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Sample records for s6 preclinical safety

  1. Time management for preclinical safety professionals.

    PubMed

    Wells, Monique Y

    2010-08-01

    A survey about time management in the workplace was distributed to obtain a sense of the level of job satisfaction among preclinical safety professionals in the current economic climate, and to encourage reflection upon how we manage time in our work environment. Roughly equal numbers of respondents (approximately 32%) identified themselves as management or staff, and approximately 27% indicated that they are consultants. Though 45.2% of respondents indicated that time management is very challenging for the profession in general, only 36.7% find it very challenging for themselves. Ten percent of respondents view time management to be exceedingly challenging for themselves. Approximately 34% of respondents indicated that prioritization of tasks was the most challenging aspect of time management for them. Focusing on an individual task was the second most challenging aspect (26%), followed equally by procrastination and delegation of tasks (12.4%). Almost equal numbers of respondents said that they would (35.2%) or might (33.3%) undertake training to improve their time management skills. Almost equal numbers of participants responded "perhaps" (44.6%) or "yes" (44.2%) to the question of whether management personnel should be trained in time management.

  2. [Preclinical evaluation of the safety of biotechnology products: specific aspects].

    PubMed

    Descotes, Jacques; Ravel, Guillaume; Vial, Thierry

    2003-01-01

    Biotechnology-derived products represent a class of increasingly numerous drugs. One of their major characteristics is extreme diversity, which requires specific approaches for the preclinical evaluation of their safety. The selection of relevant animal species is not easy, as most of these products are human-specific. Thus, only one species will often be used, i.e. primates. As most of these products are large molecules, they can be directly immunogenic. When they are human-specific, no animal model is available to predict the risk. Many biotechnology-derived products have an expected influence on the immune system. This must be taken into account in the preclinical strategy of immunotoxicity evaluation that is now required for every new drug. As conventional toxicity testing is generally limited, safety pharmacology studies should include more than the core battery of assays required by current guidelines in order to complement missing data as much as possible. Because of these particularities, a comprehensive investigation of metabolism and pharmacokinetics is not usually needed. Some products can cross-react with cellular components not intended as therapeutic targets. It is, therefore, essential to rule out the risk of possible cross-reactions that can result in adverse effects. Finally, viral safety is a crucial component of the preclinical safety evaluation of these products. Overall, biotechnology-derived products raise specific issues because of their innovative and original characteristics, and it is difficult to address all these issues if not by using a case-by-case approach.

  3. Novel technology to prepare oral formulations for preclinical safety studies.

    PubMed

    Niwa, Toshiyuki; Hashimoto, Naofumi

    2008-02-28

    A novel method to prepare oral formulations, normally suspended dosage form, for preclinical safety studies in animals has been developed using a rotation/revolution mixer. Small hard balls made of zirconia were added to the mixing process to evaluate effectiveness in making a high quality suspension. The driving with balls loaded in the cylindrical container (vessel) of the mixer was quite efficient in dispersing and milling the particles of the active pharmaceutical ingredient (API) in an aqueous medium. The API powder and a small amount of oral aqueous medium (vehicle) were successfully mixed by the spinning motion of the balls in the vessel as though the paste-like suspension was kneaded with a mortar and pestle. It was found that the milled suspension with the mean size of 10-20microm could be prepared, in addition finer milling of less than 10microm could be achieved by selecting the material of vessel. Optimum driving conditions including mixing time, size and quantity of balls, and the standard operational procedure was established using compounds varying in physicochemical properties. The particle size and quantitative analysis by HPLC showed that the resultant suspension was well-milled and highly homogeneous with the nearly intended concentration of API. The proposed method established by this experiment could be applied to the actual safety studies in the real preparation scale of oral suspension.

  4. Preclinical safety testing for cell-based products using animals.

    PubMed

    McBlane, James W

    2015-09-01

    The objectives of preclinical testing include to show why there might be therapeutic benefit in patients and to provide information on the product's toxicity. For cell-based products, given even once, there may be long term exposure and this could imply, unlike for conventional drugs, that all preclinical studies may be needed prior to first human use. The duration of exposure to cells should be studied in animals to guide toxicity assessments. Distribution of cells after administration by a route resembling that intended in humans should be studied to understand potential risks. Risk of tumour formation with the product may also need to be characterised. To the extent that this information can be generated by in vitro testing, studies in animals may not be needed and limitations on the capability of preclinical data to predict human toxicity are recognised: species-specificity make some cell products act only in humans and a human cell-product might be expected to be rejected by immunocompetent animals. Does this suggest testing in immunosuppressed animals or of development of an animal-cell product supposedly similar to the human cell product? No single answer seems to fit every situation. Copyright © 2015.

  5. Preclinical safety studies on autologous cultured human skin fibroblast transplantation.

    PubMed

    Zeng, Wei; Zhang, Shuying; Liu, Dai; Chai, Mi; Wang, Jiaqi; Zhao, Yuming

    2014-01-01

    Recently, FDA approved the clinical use of autologous fibroblasts (LAVIV™) for the improvement of nasolabial fold wrinkles in adults. The use of autologous fibroblasts for the augmentation of dermal and subcutaneous defects represents a potentially exciting natural alternative to the use of other filler materials for its long-term corrective ability and absence of allergic adverse effects proved by clinical application. However, compared to the clinical evidence, preclinical studies are far from enough. In this study, human skin-derived fibroblasts were cultured and expanded for both in vitro and in vivo observations. In vitro, the subcultured fibroblasts were divided into two groups. One set of cells underwent cell cycle and karyotype analysis at passages 5 and 10. The second group of cells was cocultured in medium with different concentrations of human skin extract D for the measurement of collagen concentration and cell count. In vivo, the subcultured fibroblasts were injected into nude mice subcutaneously. Biopsies were taken for morphology observation and specific collagen staining at 1, 2, and 3 months after injection. The results in vitro showed no significant differences in cell cycle distribution between passages 5 and 10. Cell proliferation and secretion were inhibited as the concentration of extract D increased. In vivo, the fibroblasts were remarkably denser on the experimental side with no dysplastic cells. Mitotic cells were easily observed at the end of the first month but were rare at the end of the third month. Type III collagen was detected at the end of the first month, while collagen type I was positive at the end of the second month. The content of both collagens increased as time passed. The above results indicated that the use of the autologous fibroblasts was safe, providing a basic support for clinical use of fibroblasts.

  6. A patient safety course for preclinical medical students.

    PubMed

    Shekhter, Ilya; Rosen, Lisa; Sanko, Jill; Everett-Thomas, Ruth; Fitzpatrick, Maureen; Birnbach, David

    2012-12-01

    We developed a course to introduce incoming third-year medical students to the subject of patient safety, to focus their attention on teamwork and communication, and to create an awareness of patient-safe practices that will positively impact their performance as clinicians. The course, held prior to the start of clinical rotations, consisted of lectures, web-based didactic materials, small group activities and simulation exercises, with an emphasis on experiential learning. First, students inspected a 'room of horrors', which is a simulated clinical environment riddled with errors. Second, we used lenticular puzzles in small groups to elicit teamwork behaviours that parallel real-life interactions in health care. Each team was given 8 minutes to complete a 48-piece puzzle, with five pieces removed at random and given to other teams. The salient teaching point of this exercise is that for a team to complete the task, team members must communicate with members of their own team as well as with other teams. Last, simulation scenarios provided a clinical context to reinforce the skills introduced through the puzzle exercise and lectures. The students were split into groups of six or seven members and challenged with two scenarios. Both scenarios focused on a 56-year-old man in respiratory distress. The teams were debriefed on both clinical management and teamwork. The vast majority of the students (93%) agreed that the course improved their patient safety knowledge and skills. The positive response from students to the introductory course is an important step in fostering a culture of patient safety. © Blackwell Publishing Ltd 2012.

  7. The development of neural stimulators: a review of preclinical safety and efficacy studies.

    PubMed

    Shepherd, Robert K; Villalobos, Joel; Burns, Owen; Nayagam, David

    2018-05-14

    Given the rapid expansion of the field of neural stimulation and the rigorous regulatory approval requirements required before these devices can be applied clinically, it is important that there is clarity around conducting preclinical safety and efficacy studies required for the development of this technology. The present review examines basic design principles associated with the development of a safe neural stimulator and describes the suite of preclinical safety studies that need to be considered when taking a device to clinical trial. Neural stimulators are active implantable devices that provide therapeutic intervention, sensory feedback or improved motor control via electrical stimulation of neural or neuro-muscular tissue in response to trauma or disease. Because of their complexity, regulatory bodies classify these devices in the highest risk category (Class III), and they are therefore required to go through a rigorous regulatory approval process before progressing to market. The successful development of these devices is achieved through close collaboration across disciplines including engineers, scientists and a surgical/clinical team, and the adherence to clear design principles. Preclinical studies form one of several key components in the development pathway from concept to product release of neural stimulators. Importantly, these studies provide iterative feedback in order to optimise the final design of the device. Key components of any preclinical evaluation include: in vitro studies that are focussed on device reliability and include accelerated testing under highly controlled environments; in vivo studies using animal models of the disease or injury in order to assess safety and, given an appropriate animal model, the efficacy of the technology under both passive and electrically active conditions; and human cadaver and ex vivo studies designed to ensure the device's form factor conforms to human anatomy, to optimise the surgical approach and to

  8. Development of regional chemotherapies: feasibility, safety and efficacy in clinical use and preclinical studies

    PubMed Central

    Cai, Shuang; Bagby, Taryn R; Forrest, M Laird

    2011-01-01

    Conventional oral and intravenous chemotherapies permeate throughout the body, exposing healthy tissues to similar cytotoxic drug levels as tumors. This leads to significant dose-limiting toxicities that may prevent patients from receiving sufficient treatment to overcome cancers. Therefore, a number of locoregional drug-delivery strategies have been evaluated and implemented in preclinical studies, clinical trials and in practice, in the past decades to minimize systemic toxicities from chemotherapeutic agents and to improve treatment outcomes. Localized treatment is beneficial because many cancers, such as melanoma, peritoneal cancer and breast cancer, advance locally adjacent to the site of the primary tumors prior to their circulatory invasion. In this article, we will review the feasibility, safety and efficacy of multiple localized chemotherapies in clinical use and preclinical development. PMID:22229080

  9. Validation of a Preclinical Spinal Safety Model: Effects of Intrathecal Morphine in the Neonatal Rat

    PubMed Central

    Westin, B. David; Walker, Suellen M.; Deumens, Ronald; Grafe, Marjorie; Yaksh, Tony L.

    2010-01-01

    Background Preclinical studies demonstrate increased neuroapoptosis after general anesthesia in early life. Neuraxial techniques may minimize potential risks, but there has been no systematic evaluation of spinal analgesic safety in developmental models. We aimed to validate a preclinical model for evaluating dose-dependent efficacy, spinal cord toxicity, and long term function following intrathecal morphine in the neonatal rat. Methods Lumbar intrathecal injections were performed in anesthetized rats aged postnatal day (P)3, 10 and 21. The relationship between injectate volume and segmental spread was assessed post mortem and by in-vivo imaging. To determine the antinociceptive dose, mechanical withdrawal thresholds were measured at baseline and 30 minutes following intrathecal morphine. To evaluate toxicity, doses up to the maximum tolerated were administered, and spinal cord histopathology, apoptosis and glial response were evaluated 1 and 7 days following P3 or P21 injection. Sensory thresholds and gait analysis were evaluated at P35. Results Intrathecal injection can be reliably performed at all postnatal ages and injectate volume influences segmental spread. Intrathecal morphine produced spinally-mediated analgesia at all ages with lower dose requirements in younger pups. High dose intrathecal morphine did not produce signs of spinal cord toxicity or alter long-term function. Conclusions The therapeutic ratio for intrathecal morphine (toxic dose / antinociceptive dose) was at least 300 at P3, and at least 20 at P21 (latter doses limited by side effects). This data provides relative efficacy and safety data for comparison with other analgesic preparations and contributes supporting evidence for the validity of this preclinical neonatal safety model. PMID:20526189

  10. Validation of a preclinical spinal safety model: effects of intrathecal morphine in the neonatal rat.

    PubMed

    Westin, B David; Walker, Suellen M; Deumens, Ronald; Grafe, Marjorie; Yaksh, Tony L

    2010-07-01

    Preclinical studies demonstrate increased neuroapoptosis after general anesthesia in early life. Neuraxial techniques may minimize potential risks, but there has been no systematic evaluation of spinal analgesic safety in developmental models. We aimed to validate a preclinical model for evaluating dose-dependent efficacy, spinal cord toxicity, and long-term function after intrathecal morphine in the neonatal rat. Lumbar intrathecal injections were performed in anesthetized rats aged postnatal day (P) 3, 10, and 21. The relationship between injectate volume and segmental spread was assessed postmortem and by in vivo imaging. To determine the antinociceptive dose, mechanical withdrawal thresholds were measured at baseline and 30 min after intrathecal morphine. To evaluate toxicity, doses up to the maximum tolerated were administered, and spinal cord histopathology, apoptosis, and glial response were evaluated 1 and 7 days after P3 or P21 injection. Sensory thresholds and gait analysis were evaluated at P35. Intrathecal injection can be reliably performed at all postnatal ages and injectate volume influences segmental spread. Intrathecal morphine produced spinally mediated analgesia at all ages with lower dose requirements in younger pups. High-dose intrathecal morphine did not produce signs of spinal cord toxicity or alter long-term function. The therapeutic ratio for intrathecal morphine (toxic dose/antinociceptive dose) was at least 300 at P3 and at least 20 at P21 (latter doses limited by side effects). These data provide relative efficacy and safety for comparison with other analgesic preparations and contribute supporting evidence for the validity of this preclinical neonatal safety model.

  11. Preclinical safety and efficacy of a new recombinant FIX drug product for treatment of hemophilia B.

    PubMed

    Dietrich, Barbara; Schiviz, Alexandra; Hoellriegl, Werner; Horling, Frank; Benamara, Karima; Rottensteiner, Hanspeter; Turecek, Peter L; Schwarz, Hans Peter; Scheiflinger, Friedrich; Muchitsch, Eva-Maria

    2013-11-01

    Baxter has developed a new recombinant factor IX (rFIX) drug product (BAX326) for treating patients with hemophilia B, or congenital FIX deficiency. An extensive preclinical program evaluated the pharmacokinetics, efficacy, and safety of BAX326 in different species. The efficacy of BAX326 was tested in three mouse models of primary pharmacodynamics: tail-tip bleeding, carotid occlusion, and thrombelastography. The pharmacokinetics was evaluated after a single intravenous bolus injection in mice, rats, and macaques. Toxicity was assessed in rats and macaques, safety pharmacology in rabbits and macaques, and immunogenicity in mice. BAX326 was shown to be efficacious in all three primary pharmacodynamic studies (P ≤ 0.0076). Hemostatic efficacy was dose related and similar for the three lots tested. Pharmacokinetic results showed that rFIX activity and rFIX antigen concentrations declined in a bi-phasic manner, similar to a previously licensed rFIX product. BAX326 was well tolerated in rabbits and macaques at all dose levels; no thrombogenic events and no adverse clinical, respiratory, or cardiovascular effects occurred. BAX326 was also shown to have a similar immunogenicity profile to the comparator rFIX product in mice. These results demonstrate that BAX326 has a favorable preclinical safety and efficacy profile, predictive of a comparable effect to that of the previously licensed rFIX in humans.

  12. Preclinical imaging methods for assessing the safety and efficacy of regenerative medicine therapies

    NASA Astrophysics Data System (ADS)

    Scarfe, Lauren; Brillant, Nathalie; Kumar, J. Dinesh; Ali, Noura; Alrumayh, Ahmed; Amali, Mohammed; Barbellion, Stephane; Jones, Vendula; Niemeijer, Marije; Potdevin, Sophie; Roussignol, Gautier; Vaganov, Anatoly; Barbaric, Ivana; Barrow, Michael; Burton, Neal C.; Connell, John; Dazzi, Francesco; Edsbagge, Josefina; French, Neil S.; Holder, Julie; Hutchinson, Claire; Jones, David R.; Kalber, Tammy; Lovatt, Cerys; Lythgoe, Mark F.; Patel, Sara; Patrick, P. Stephen; Piner, Jacqueline; Reinhardt, Jens; Ricci, Emanuelle; Sidaway, James; Stacey, Glyn N.; Starkey Lewis, Philip J.; Sullivan, Gareth; Taylor, Arthur; Wilm, Bettina; Poptani, Harish; Murray, Patricia; Goldring, Chris E. P.; Park, B. Kevin

    2017-10-01

    Regenerative medicine therapies hold enormous potential for a variety of currently incurable conditions with high unmet clinical need. Most progress in this field to date has been achieved with cell-based regenerative medicine therapies, with over a thousand clinical trials performed up to 2015. However, lack of adequate safety and efficacy data is currently limiting wider uptake of these therapies. To facilitate clinical translation, non-invasive in vivo imaging technologies that enable careful evaluation and characterisation of the administered cells and their effects on host tissues are critically required to evaluate their safety and efficacy in relevant preclinical models. This article reviews the most common imaging technologies available and how they can be applied to regenerative medicine research. We cover details of how each technology works, which cell labels are most appropriate for different applications, and the value of multi-modal imaging approaches to gain a comprehensive understanding of the responses to cell therapy in vivo.

  13. Preclinical QT safety assessment: cross-species comparisons and human translation from an industry consortium.

    PubMed

    Holzgrefe, Henry; Ferber, Georg; Champeroux, Pascal; Gill, Michael; Honda, Masaki; Greiter-Wilke, Andrea; Baird, Theodore; Meyer, Olivier; Saulnier, Muriel

    2014-01-01

    In vivo models have been required to demonstrate relative cardiac safety, but model sensitivity has not been systematically investigated. Cross-species and human translation of repolarization delay, assessed as QT/QTc prolongation, has not been compared employing common methodologies across multiple species and sites. Therefore, the accurate translation of repolarization results within and between preclinical species, and to man, remains problematic. Six pharmaceutical companies entered into an informal consortium designed to collect high-resolution telemetered data in multiple species (dog; n=34, cynomolgus; n=37, minipig; n=12, marmoset; n=14, guinea pig; n=5, and man; n=57). All animals received vehicle and varying doses of moxifloxacin (3-100 mg/kg, p.o.) with telemetered ECGs (≥500 Hz) obtained for 20-24h post-dose. Individual probabilistic QT-RR relationships were derived for each subject. The rate-correction efficacies of the individual (QTca) and generic correction formulae (Bazett, Fridericia, and Van de Water) were objectively assessed as the mean squared slopes of the QTc-RR relationships. Normalized moxifloxacin QTca responses (Veh Δ%/μM) were derived for 1h centered on the moxifloxacin Tmax. All QT-RR ranges demonstrated probabilistic uncertainty; slopes varied distinctly by species where dog and human exhibited the lowest QT rate-dependence, which was much steeper in the cynomolgus and guinea pig. Incorporating probabilistic uncertainty, the normalized QTca-moxifloxacin responses were similarly conserved across all species, including man. The current results provide the first unambiguous evidence that all preclinical in vivo repolarization assays, when accurately modeled and evaluated, yield results that are consistent with the conservation of moxifloxacin-induced QT prolongation across all common preclinical species. Furthermore, these outcomes are directly transferable across all species including man. The consortium results indicate that the

  14. The Sheep as a Model of Preclinical Safety and Pharmacokinetic Evaluations of Candidate Microbicides

    PubMed Central

    Cameron, David; Dias, Nicola; Holding, Jeremy; Muntendam, Alex; Oostebring, Freddy; Dreier, Peter; Rohan, Lisa; Nuttall, Jeremy

    2015-01-01

    When developing novel microbicide products for the prevention of HIV infection, the preclinical safety program must evaluate not only the active pharmaceutical ingredient but also the product itself. To that end, we applied several relatively standard toxicology study methodologies to female sheep, incorporating an assessment of the pharmacokinetics, safety, tolerability, and local toxicity of a dapivirine-containing human vaginal ring formulation (Dapivirine Vaginal Ring-004). We performed a 3-month general toxicology study, a preliminary pharmacokinetic study using drug-loaded vaginal gel, and a detailed assessment of the kinetics of dapivirine delivery to plasma, vaginal, and rectal fluid and rectal, vaginal, and cervical tissue over 28 days of exposure and 3 and 7 days after removal of the ring. The findings of the general toxicology study supported the existing data from both preclinical and clinical studies in that there were no signs of toxicity related to dapivirine. In addition, the presence of the physical dapivirine ring did not alter local or systemic toxicity or the pharmacokinetics of dapivirine. Pharmacokinetic studies indicated that the dapivirine ring produced significant vaginal tissue levels of dapivirine. However, no dapivirine was detected in cervical tissue samples using the methods described here. Plasma and vaginal fluid levels were lower than those in previous clinical studies, while there were detectable dapivirine levels in the rectal tissue and fluid. All tissue and fluid levels tailed off rapidly to undetectable levels following removal of the ring. The sheep represents a very useful model for the assessment of the safety and pharmacokinetics of microbicide drug delivery devices, such as the vaginal ring. PMID:25845860

  15. The sheep as a model of preclinical safety and pharmacokinetic evaluations of candidate microbicides.

    PubMed

    Holt, Jonathon D S; Cameron, David; Dias, Nicola; Holding, Jeremy; Muntendam, Alex; Oostebring, Freddy; Dreier, Peter; Rohan, Lisa; Nuttall, Jeremy

    2015-07-01

    When developing novel microbicide products for the prevention of HIV infection, the preclinical safety program must evaluate not only the active pharmaceutical ingredient but also the product itself. To that end, we applied several relatively standard toxicology study methodologies to female sheep, incorporating an assessment of the pharmacokinetics, safety, tolerability, and local toxicity of a dapivirine-containing human vaginal ring formulation (Dapivirine Vaginal Ring-004). We performed a 3-month general toxicology study, a preliminary pharmacokinetic study using drug-loaded vaginal gel, and a detailed assessment of the kinetics of dapivirine delivery to plasma, vaginal, and rectal fluid and rectal, vaginal, and cervical tissue over 28 days of exposure and 3 and 7 days after removal of the ring. The findings of the general toxicology study supported the existing data from both preclinical and clinical studies in that there were no signs of toxicity related to dapivirine. In addition, the presence of the physical dapivirine ring did not alter local or systemic toxicity or the pharmacokinetics of dapivirine. Pharmacokinetic studies indicated that the dapivirine ring produced significant vaginal tissue levels of dapivirine. However, no dapivirine was detected in cervical tissue samples using the methods described here. Plasma and vaginal fluid levels were lower than those in previous clinical studies, while there were detectable dapivirine levels in the rectal tissue and fluid. All tissue and fluid levels tailed off rapidly to undetectable levels following removal of the ring. The sheep represents a very useful model for the assessment of the safety and pharmacokinetics of microbicide drug delivery devices, such as the vaginal ring. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Value of shared preclinical safety studies - The eTOX database.

    PubMed

    Briggs, Katharine; Barber, Chris; Cases, Montserrat; Marc, Philippe; Steger-Hartmann, Thomas

    2015-01-01

    A first analysis of a database of shared preclinical safety data for 1214 small molecule drugs and drug candidates extracted from 3970 reports donated by thirteen pharmaceutical companies for the eTOX project (www.etoxproject.eu) is presented. Species, duration of exposure and administration route data were analysed to assess if large enough subsets of homogenous data are available for building in silico predictive models. Prevalence of treatment related effects for the different types of findings recorded were analysed. The eTOX ontology was used to determine the most common treatment-related clinical chemistry and histopathology findings reported in the database. The data were then mined to evaluate sensitivity of established in vivo biomarkers for liver toxicity risk assessment. The value of the database to inform other drug development projects during early drug development is illustrated by a case study.

  17. Preclinical efficacy and safety of herbal formulation for management of wounds.

    PubMed

    Ogwang, P E; Nyafuono, J; Agwaya, Moses; Omujal, F; Tumusiime, H R; Kyakulaga, A H

    2011-09-01

    Medicinal plants in Uganda and other developing countries have been scientifically demonstrated to have medicinal benefits but few or none have been translated to products for clinical use. Most herbal products developed by local herbalists and sold to the public are not standardized and lack efficacy and safety data to support use. To formulate from two Ugandan medicinal plants a herbal product for wound management and test its preclinical safety and efficacy using rat models. Thirty (30) Wistar albino rats were randomly divided into three groups and wounds were surgically created on the mid-dorsal region. The wounds were treated topically with distilled water (group I), Jena(®) (group II)and Neomycin sulfate cream (group III). The effects of the treatments on rate of wound closure, epithelialisation time and histological organization of tissue were assessed. The herbal formulation (Jena) had a significantly higher rate of wound closure than neomycin (p<0.05) which itself was better than distilled water. Epithelialisation time was also significantly shorter for the herbal product (p<0.01). Histological picture revealed more collagen fibers, less inflammation and better tissue remodeling for rats treated with herbal product. The herbal formulation Jena(®) systematically designed and formulated based on two Ugandan medicinal plants is according to this study better than neomycin and probably other imported products for wound management in Uganda. We recommend its trial in a clinical setting as an alternative in wound management.

  18. Preclinical study and phase I clinical safety evaluation of recombinant Mycobacterium tuberculosis ESAT6 protein.

    PubMed

    Du, Wei-Xin; Chen, Bao-Wen; Lu, Jin-Biao; Gao, Meng-Qiu; Shen, Xiao-Bing; Yang, Lei; Su, Cheng; Wang, Guo-Zhi; Sun, Qing-feng; Xu, Miao

    2013-05-15

    To investigate the ability of rESAT6 to identify different mycobacteria-sensitized guinea pigs and its safety in preclinical and phase I clinical study. Guinea pigs were sensitized with different Mycobacteria. After sensitization, all animals were intradermally injected with rESAT6 and either PPD or PPD-B. At 24 h after the injection, the erythema of the injection sites were measured using a double-blind method. For the preclinical safety study, different doses of rESAT6 and BSA were given 3 times intramuscularly to guinea pigs. On day 14 after the final immunization, the guinea pigs were intravenously injected with the same reagents in the hind legs and the allergic reactions were observed. A single-center, randomized, open phase I clinical trial was employed. The skin test was conducted in 32 healthy volunteers aged 19-65 years with 0.1 µg, 0.5 µg, and 1 µg rESAT6. Physical examination and laboratory tests were performed before and after the skin test and adverse reactions were monitored. The volunteers' local and systemic adverse reactions and adverse events were recorded for 7 days. Positive PPD or PPD-B skin tests were observed in all Mycobacteria-sensitized guinea pigs; the diameters of erythema were all >10 mm. The rESAT6 protein induced a positive skin test result in the guinea pigs sensitized with MTB, M. bovis, M. africanum and M. kansasii; the diameters of erythema were 14.7±2.0, 9.3±3.8, 18.7±2.4, and 14.8±4.2 mm, respectively. A negative skin test result was detected in BCG-vaccinated and other NTM-sensitized guinea pigs. The rESAT6 caused no allergic symptoms, but many allergic reactions, such as cough, dyspnea, and even death, were observed in the guinea pigs who were administered BSA. During the phase I clinical trial, no adverse reactions were found in the 0.1 µg rESAT6 group, but in the 0.5 µg rESAT6 group 2 volunteers reported pain and 1 reported itching, and in the 1 µg rESAT6 group there was 1 case of pain, 1 case of itching, and 1

  19. Technological Advances in Cardiovascular Safety Assessment Decrease Preclinical Animal Use and Improve Clinical Relevance.

    PubMed

    Berridge, Brian R; Schultze, A Eric; Heyen, Jon R; Searfoss, George H; Sarazan, R Dustan

    2016-12-01

    Cardiovascular (CV) safety liabilities are significant concerns for drug developers and preclinical animal studies are predominately where those liabilities are characterized before patient exposures. Steady progress in technology and laboratory capabilities is enabling a more refined and informative use of animals in those studies. The application of surgically implantable and telemetered instrumentation in the acute assessment of drug effects on CV function has significantly improved historical approaches that involved anesthetized or restrained animals. More chronically instrumented animals and application of common clinical imaging assessments like echocardiography and MRI extend functional and in-life structural assessments into the repeat-dose setting. A growing portfolio of circulating CV biomarkers is allowing longitudinal and repeated measures of cardiac and vascular injury and dysfunction better informing an understanding of temporal pathogenesis and allowing earlier detection of undesirable effects. In vitro modeling systems of the past were limited by their lack of biological relevance to the in vivo human condition. Advances in stem cell technology and more complex in vitro modeling platforms are quickly creating more opportunity to supplant animals in our earliest assessments for liabilities. Continuing improvement in our capabilities in both animal and nonanimal modeling should support a steady decrease in animal use for primary liability identification and optimize the translational relevance of the animal studies we continue to do. © The Author 2016. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Preclinical safety study of a recombinant Streptococcus pyogenes vaccine formulated with aluminum adjuvant.

    PubMed

    HogenEsch, Harm; Dunham, Anisa; Burlet, Elodie; Lu, Fangjia; Mosley, Yung-Yi C; Morefield, Garry

    2017-02-01

    A recombinant vaccine composed of a fusion protein formulated with aluminum hydroxide adjuvant is under development for protection against diseases caused by Streptococcus pyogenes. The safety and local reactogenicity of the vaccine was assessed by a comprehensive series of clinical, pathologic and immunologic tests in preclinical experiments. Outbred mice received three intramuscular injections of 1/5th of the human dose (0.1 ml) and rabbits received two injections of the full human dose. Control groups received adjuvant or protein antigen. The vaccine did not cause clinical evidence of systemic toxicity in mice or rabbits. There was a transient increase of peripheral blood neutrophils after the third vaccination of mice. In addition, the concentration of acute phase proteins serum amyloid A and haptoglobin was significantly increased 1 day after injection of the vaccine in mice. There was mild transient swelling and erythema of the injection site in both mice and rabbits. Treatment-related pathology was limited to inflammation at the injection site and accumulation of adjuvant-containing macrophages in the draining lymph nodes. In conclusion, the absence of clinical toxicity in two animal species suggest that the vaccine is safe for use in a phase I human clinical trial. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Preclinical safety evaluation of human platelets treated with antimicrobial peptides in severe combined immunodeficient mice.

    PubMed

    Bosch-Marcé, Marta; Mohan, Ketha V K; Gelderman, Monique P; Ryan, Patricia L; Russek-Cohen, Estelle; Atreya, Chintamani D

    2014-03-01

    Bacterial sepsis is a complication attributed to room temperature (RT)-stored platelets (PLTs) in transfusion medicine. Antimicrobial peptides (AMPs) are emerging as new therapeutic agents against microbes. We had previously demonstrated bactericidal activity of select synthetic AMPs against six types of bacteria in stored PLTs. In this report, we tested these AMPs for their potential antibody response and interference with the recovery and survival of human PLTs in an animal model. Two separate studies were conducted to evaluate the safety of the synthetic AMPs. 1) Two AMPs (PD3 and PD4), derived from thrombin-induced human PLT microbicidal protein, and four repeats of arginine-tryptophan (RW), containing two to five repeats (RW2-RW5), were tested in rabbits for potential antibody response. 2) RT-stored human PLTs treated for 2 hours with each of the six AMPs individually or with phosphate-buffered saline (PBS) alone were infused into severe combined immunodeficient (SCID) mice to evaluate their in vivo recovery and survival by flow cytometry. Except for PD3, which showed a weak immune response, all other peptides did not induce any detectable antibodies in rabbits. Furthermore, all six AMPs tested did not significantly affect the in vivo recovery and survival of human PLTs in SCID mice compared to PBS alone-treated PLTs. Preclinical evaluation studies reported here demonstrate that the selected AMPs used in the study did not adversely affect the human PLT recovery and survival in the SCID mouse model, suggesting further study of AMPs toward addressing the bacterial contamination of PLTs. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  2. Rheolytic thrombectomy with use of the AngioJet-F105 catheter: preclinical evaluation of safety.

    PubMed

    Sharafuddin, M J; Hicks, M E; Jenson, M L; Morris, J E; Drasler, W J; Wilson, G J

    1997-01-01

    A preclinical evaluation of the safety of the AngioJet-F105 rheolytic thrombectomy catheter. The AngioJet-F105 catheter uses multiple retrograde high-speed fluid jets impinging on a primary aspiration lumen to create a hydrodynamic recirculation vortex that traps and fragments adjacent thrombus, with simultaneous evacuation of the resulting debris through the aspiration lumen. The effect of the AngioJet on treated vessels was evaluated in 10 canines. Vascular integrity on histopathologic examination and endothelial coverage on scanning electron microscopic study were examined in 15 vessel segments treated with the AngioJet-F105 catheter, compared with four vessel segments subjected to the Fogarty balloon maneuver, and 10 untreated vessel segments. The size distribution of particulate debris, upstream and downstream, after thrombectomy was determined in a flow-circuit model simulating the superficial femoral artery. Aliquots from the downstream effluent were then injected into the renal arteries of two healthy canines. The device caused only minimal focal endothelial denudation and no significant deep injury. No significant difference in endothelial coverage occurred in AngioJet-treated vessel segments compared to untreated control vessels (mean +/- standard deviation: 88.0% +/- 7.9% vs 89.7% +/- 11.6%, P = .77). Vessels treated with the Fogarty balloon pullback maneuver had significantly less residual endothelial coverage (58.0% +/- 8.0%, P < .03). Particulate microemboli in the effluent of the flow model accounted for 12% of the initial thrombus volume (0% > 100 microm, 99.83% < or = 10 microm). Histopathologic evaluation of the four renal beds injected with the resulting debris demonstrated no signs of necrosis. A moderate transient increase in plasma-free hemoglobin occurred, with a mild corresponding decrease in hematocrit. The AngioJet-F105 catheter resulted in only mild and focal injury to the treated vessels. The vast majority of resulting particulate debris

  3. Evaluation of focused multipolar stimulation for cochlear implants: a preclinical safety study

    NASA Astrophysics Data System (ADS)

    Shepherd, Robert K.; Wise, Andrew K.; Enke, Ya Lang; Carter, Paul M.; Fallon, James B.

    2017-08-01

    Objective. Cochlear implants (CIs) have a limited number of independent stimulation channels due to the highly conductive nature of the fluid-filled cochlea. Attempts to develop highly focused stimulation to improve speech perception in CI users includes the use of simultaneous stimulation via multiple current sources. Focused multipolar (FMP) stimulation is an example of this approach and has been shown to reduce interaction between stimulating channels. However, compared with conventional biphasic current pulses generated from a single current source, FMP is a complex stimulus that includes extended periods of stimulation before charge recovery is achieved, raising questions on whether chronic stimulation with this strategy is safe. The present study evaluated the long-term safety of intracochlear stimulation using FMP in a preclinical animal model of profound deafness. Approach. Six cats were bilaterally implanted with scala tympani electrode arrays two months after deafening, and received continuous unilateral FMP stimulation at levels that evoked a behavioural response for periods of up to 182 d. Electrode impedance, electrically-evoked compound action potentials (ECAPs) and auditory brainstem responses (EABRs) were monitored periodically over the course of the stimulation program from both the stimulated and contralateral control cochleae. On completion of the stimulation program cochleae were examined histologically and the electrode arrays were evaluated for evidence of platinum (Pt) corrosion. Main results. There was no significant difference in electrode impedance between control and chronically stimulated electrodes following long-term FMP stimulation. Moreover, there was no significant difference between ECAP and EABR thresholds evoked from control or stimulated cochleae at either the onset of stimulation or at completion of the stimulation program. Chronic FMP stimulation had no effect on spiral ganglion neuron (SGN) survival when compared with

  4. Precision Pulse Capsulotomy: Preclinical Safety and Performance of a New Capsulotomy Technology.

    PubMed

    Chang, David F; Mamalis, Nick; Werner, Liliana

    2016-02-01

    To assess the preclinical safety and performance of a new precision pulse capsulotomy (PPC) method. Human cadaver eye studies and surgical, slit-lamp, and histopathologic evaluation in a consecutive series of 20 live rabbits. Human cadaver eyes and New Zealand white rabbits. Precision pulse capsulotomy uses a highly focused, fast, multipulse, low-energy discharge to produce a perfectly round anterior capsulotomy instantaneously and simultaneously along all 360°. Capsulotomies are performed using a disposable handpiece with a soft collapsible tip and circular nitinol cutting element. Miyake-Apple imaging and scanning electron microscopy (SEM) of PPC were conducted in human cadaver eyes. Surgical, postoperative slit-lamp, and histopathologic assessments of PPC were performed in 20 live rabbits and were compared with manual continuous curvilinear capsulorrhexis (CCC) in the fellow eye. Anterior chamber (AC) thermocouple temperature measurements were evaluated in a subset of rabbit eyes. Capsulotomy edge circularity, SEM morphologic features and zonular movement with PPC in human cadaver eyes. Anterior chamber temperature during PPC and grading of ocular inflammation, corneal endothelial damage, anterior capsular opacification (ACO), and posterior capsular opacification (PCO). Miyake-Apple imaging showed minimal zonular stress, and thermocouple measurements demonstrated negligible AC temperature changes during PPC. Precision pulse capsulotomy produced round, complete capsulotomies in all 20 rabbit eyes, leading to successful in-the-bag intraocular lens (IOL) implantation. Slit-lamp examinations at 3 days and 1, 2, and 4 weeks after surgery showed no significant differences between PPC and CCC in corneal edema, AC inflammatory reaction, capsular fibrosis, ACO, and PCO. Postmortem studies showed no difference in the corneal endothelium between PPC and CCC eyes. All IOLs were well centered in PPC eyes, and histopathologic analysis showed no greater inflammatory

  5. Comparison of electrophysiological data from human-induced pluripotent stem cell-derived cardiomyocytes to functional preclinical safety assays.

    PubMed

    Harris, Kate; Aylott, Mike; Cui, Yi; Louttit, James B; McMahon, Nicholas C; Sridhar, Arun

    2013-08-01

    Human-induced pluripotent stem cell cardiomyocytes (hiPSC-CMs) are a potential source to develop assays for predictive electrophysiological safety screening. Published studies show that the relevant physiology and pharmacology exist but does not show the translation between stem cell cardiomyocyte assays and other preclinical safety screening assays, which is crucial for drug discovery and safety scientists and the regulators. Our studies are the first to show the pharmacology of ion channel blockade and compare them with existing functional cardiac electrophysiology studies. Ten compounds (a mixture of pure hERG [E-4031 and Cisapride], hERG and sodium [Flecainide, Mexiletine, Quinidine, and Terfenadine], calcium channel blockers [Nifedipine and Verapamil], and two proprietary compounds [GSK A and B]) were tested, and results from hiPSC-CMs studied on multielectrode arrays (MEA) were compared with other preclincial models and clinical drug concentrations and effects using integrated risk assessment plots. All ion channel blockers produced (1) functional effects on repolarization and depolarization around the IC25 and IC50 values and (2) excessive blockade of hERG and/or blockade of sodium current precipitated arrhythmias. Our MEA data show that hiPSC-CMs demonstrate relevant pharmacology and show excellent correlations to current functional cardiac electrophysiological studies. Based on these results, MEA assays using iPSC-CMs offer a reliable, cost effective, and surrogate to preclinical in vitro testing, in addition to the 3Rs (refine, reduce, and replace animals in research) benefit.

  6. Neuraxial Analgesia In Neonates And Infants: Review of Clinical and Preclinical Strategies for the Development of Safety and Efficacy Data

    PubMed Central

    Walker, Suellen M.; Yaksh, Tony L.

    2015-01-01

    Neuraxial agents provide robust pain control, have the potential to improve outcomes, and are an important component of the perioperative care of children. Opioids or clonidine improve analgesia when added to perioperative epidural infusions; analgesia is significantly prolonged by addition of clonidine, ketamine, neostigmine or tramadol to single shot caudal injections of local anesthetic; and neonatal intrathecal anesthesia/analgesia is increasing in some centers. However, it is difficult to determine the relative risk-benefit of different techniques and drugs without detailed and sensitive data related to analgesia requirements, side-effects, and follow-up. Current data related to benefits and complications in neonates and infants are summarized, but variability in current neuraxial drug use reflects the relative lack of high quality evidence. Recent preclinical reports of adverse effects of general anesthetics on the developing brain have increased awareness of the potential benefit of neuraxial anesthesia/analgesia to avoid or reduce general anesthetic dose requirements. However, the developing spinal cord is also vulnerable to drug-related toxicity, and although there are well-established preclinical models and criteria for assessing spinal cord toxicity in adult animals, until recently there had been no systematic evaluation during early life. Therefore, the second half of this review presents preclinical data evaluating age-dependent changes in the pharmacodynamic response to different spinal analgesics, and recent studies evaluating spinal toxicity in specific developmental models. Finally, we advocate use of neuraxial agents with the widest demonstrable safety margin and suggest minimum standards for preclinical evaluation prior to adoption of new analgesics or preparations into routine clinical practice. PMID:22798528

  7. Use of a collaborative tool to simplify the outsourcing of preclinical safety studies: an insight into the AstraZeneca-Charles River Laboratories strategic relationship.

    PubMed

    Martin, Frederic D C; Benjamin, Amanda; MacLean, Ruth; Hollinshead, David M; Landqvist, Claire

    2017-12-01

    In 2012, AstraZeneca entered into a strategic relationship with Charles River Laboratories whereby preclinical safety packages comprising safety pharmacology, toxicology, formulation analysis, in vivo ADME, bioanalysis and pharmacokinetics studies are outsourced. New processes were put in place to ensure seamless workflows with the aim of accelerating the delivery of new medicines to patients. Here, we describe in more detail the AstraZeneca preclinical safety outsourcing model and the way in which a collaborative tool has helped to translate the processes in AstraZeneca and Charles River Laboratories into simpler integrated workflows that are efficient and visible across the two companies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Pre-clinical and Clinical Safety Studies of CMX-2043: A Cytoprotective Lipoic Acid Analogue for Ischaemia–Reperfusion Injury

    PubMed Central

    Kates, Steven A; Lader, Alan S; Casale, Ralph; Beeuwkes, Reinier

    2014-01-01

    CMX-2043 is an α-lipoic acid analogue targeted to reduction of cellular injury and organ damage due to ischaemia–reperfusion injury (IRI). It has been shown to be effective in a rat model of cardiac IRI. The studies here reported evaluate its safety and pharmacokinetic profile in preparation for human clinical studies in procedures associated with IRI. Safety and tolerability were tested in standard pre-clinical in vitro and animal models and in a Phase 1 human clinical trial. CMX-2043 did not bind to a wide range of receptors and specific targets at approximately 4 μg/mL (10 μM). It was not mutagenic by Ames assay, did not produce chromosome aberrations in Chinese hamster ovary (CHO) cells, and was negative for clastogenic potential. Toxicological studies in rats including both single and 14-day repeat intravenous doses and in dogs (single intravenous dose) with a 2-week recovery period were conducted. The NOAEL in rats and dogs was 30 and >10 mg/kg, respectively. No serious adverse events were reported in a placebo-controlled, sequential dose escalation Phase 1 clinical trial. The low toxicity in the pre-clinical studies and the absence of adverse events in the Phase 1 trial have supported investigation of CMX-2043 in a human efficacy trial. PMID:24751172

  9. A pre-clinical safety study of PEGylated recombinant human endostatin (M2ES) in Sprague Dawley rats.

    PubMed

    Geng, Xingchao; Guo, Lifang; Liu, Li; Wang, Chao; Peng, Qian; Qi, Weihong; Sun, Li; Liu, Xiaomeng; Miao, Yufa; Lin, Zhi; Fu, Yan; Luo, Yongzhang; Li, Bo

    2018-06-01

    PEGylated recombinant human endostatin (M 2 ES) exhibited prolonged serum half-life and enhanced antitumor activity when compared with endostatin. A pre-clinical study was performed to evaluate the safety of M 2 ES in rats. After intravenous (IV) infusions of M 2 ES at a dose level of 3, 15 and 75 mg/kg in Sprague Dawley (SD) rats, M 2 ES was well tolerated in animals, with no observable changes in clinical observation, body weight, food consumption, urine analysis, hematology and serum biochemical analysis. The increase of kidney weights, and slight to severe vacuolation and necrosis of proximal tubule epithelial cells in kidney were observed in 15 and 75 mg/kg M 2 ES groups, but this adverse-effect was reversible. In summary, the major toxicity target organ of M 2 ES might be kidney, and the no observed adverse effect level (NOAEL) of M 2 ES in rats was 3 mg/kg in this study. These pre-clinical safety data contribute to the initiation of the ongoing clinical study. Copyright © 2018. Published by Elsevier Inc.

  10. Magnetic resonance image guided transurethral ultrasound prostate ablation: a preclinical safety and feasibility study with 28-day followup.

    PubMed

    Burtnyk, Mathieu; Hill, Tracy; Cadieux-Pitre, Heather; Welch, Ian

    2015-05-01

    We determine the safety and feasibility of magnetic resonance image guided transurethral ultrasound prostate ablation using active temperature feedback control in a preclinical canine model with 28-day followup. After a long acclimatization period we performed ultrasound treatment in 8 subjects using the magnetic resonance image guided TULSA-PRO™ transurethral ultrasound prostate ablation system. Comprehensive examinations and observations were done before and throughout the 28-day followup, including assessment of clinically significant treatment related adverse events. In addition to gross pathology evaluation, extensive histopathological analysis was done to assess cell kill inside and outside the prostate. We evaluated prostate conformal heating by comparing the spatial difference between the treatment plan and the 55C isotherm measured on magnetic resonance imaging thermometry acquired during treatment. These findings were confirmed on contrast enhanced magnetic resonance imaging immediately after treatment and at 28 days. Clinically there were no adverse events in any of the 8 subjects throughout the 28-day followup. All subjects had normal urinary and bowel function. Gross necropsy and histology confirmed that the intended thermal cell kill was confined to the prostate. No surrounding tissue was damaged, including the rectum and the external urinary sphincter. Conformal heating was achieved with an average -0.9 mm accuracy and 0.9 mm precision. Contrast enhanced magnetic resonance imaging and histological analysis confirmed tissue ablation in targeted areas of the prostate. Urethral tissue was spared from thermal damage. Magnetic resonance image guided transurethral ultrasound is a safe, feasible procedure for accurate and precise conformal thermal ablation of prostate tissue, as demonstrated in a preclinical model with 28-day followup. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights

  11. [Preclinical safety evaluation of chloral hydrate after topical application using the example of psoriatic itch].

    PubMed

    Wohlrab, J; Gilbrich, F; Wolff, L; Fischer, M; Philipp, S

    2017-03-01

    Psoriasis is known today as a T‑cell-mediated autoimmunological systemic disease. The chronic inflammatory processes involve neuroimmunological factors that are held responsible not only for various aspects of psychiatric-neurological comorbidities but also for neurosensory problems, primarily itching. Amongst other things, the significance of GABA A receptors are often discussed in this context. The topical use of chloral hydrate in semisolid preparations for antipruritic therapy goes back to Neisser and is currently experiencing a revival in individually manufactured formulations. However, it is currently unknown whether the unwanted side effects that are described for systemic use of chloral hydrate are also relevant for topical application. For lack of clinical safety data, preclinical tests for cutaneous cytotoxicity and calculations for systemic bioavailability after topical application have been performed. The present data cannot fully remove safety concerns for topical application of chloral hydrate in the formulation favoured by the NRF (Neues Rezepturformularium)-the so-called 1‑2-3-cream. A twice daily use of the 1‑2-3-cream on a maximum of 10% of the body surface can be regarded as safe. For a better assessment of harmlessness, tests for cutaneous bioavailability (concentration-time profile) on human skin and clinical studies would be necessary.

  12. Pre-clinical Safety and Off-Target Studies to Support Translation of AAV-Mediated RNAi Therapy for FSHD.

    PubMed

    Wallace, Lindsay M; Saad, Nizar Y; Pyne, Nettie K; Fowler, Allison M; Eidahl, Jocelyn O; Domire, Jacqueline S; Griffin, Danielle A; Herman, Adam C; Sahenk, Zarife; Rodino-Klapac, Louise R; Harper, Scott Q

    2018-03-16

    RNAi emerged as a prospective molecular therapy nearly 15 years ago. Since then, two major RNAi platforms have been under development: oligonucleotides and gene therapy. Oligonucleotide-based approaches have seen more advancement, with some promising therapies that may soon reach market. In contrast, vector-based approaches for RNAi therapy have remained largely in the pre-clinical realm, with limited clinical safety and efficacy data to date. We are developing a gene therapy approach to treat the autosomal-dominant disorder facioscapulohumeral muscular dystrophy. Our strategy involves silencing the myotoxic gene DUX4 using adeno-associated viral vectors to deliver targeted microRNA expression cassettes (miDUX4s). We previously demonstrated proof of concept for this approach in mice, and we are now taking additional steps here to assess safety issues related to miDUX4 overexpression and sequence-specific off-target silencing. In this study, we describe improvements in vector design and expansion of our miDUX4 sequence repertoire and report differential toxicity elicited by two miDUX4 sequences, of which one was toxic and the other was not. This study provides important data to help advance our goal of translating RNAi gene therapy for facioscapulohumeral muscular dystrophy.

  13. Preclinical immunogenicity and safety of a Group A streptococcal M protein-based vaccine candidate

    PubMed Central

    Batzloff, Michael R.; Fane, Anne; Gorton, Davina; Pandey, Manisha; Rivera-Hernandez, Tania; Calcutt, Ainslie; Yeung, Grace; Hartas, Jon; Johnson, Linda; Rush, Catherine M.; McCarthy, James; Ketheesan, Natkunam; Good, Michael F.

    2016-01-01

    ABSTRACT Streptococcus pyogenes (group A streptococcus, GAS) causes a wide range of clinical manifestations ranging from mild self-limiting pyoderma to invasive diseases such as sepsis. Also of concern are the post-infectious immune-mediated diseases including rheumatic heart disease. The development of a vaccine against GAS would have a large health impact on populations at risk of these diseases. However, there is a lack of suitable models for the safety evaluation of vaccines with respect to post-infectious complications. We have utilized the Lewis Rat model for cardiac valvulitis to evaluate the safety of the J8-DT vaccine formulation in parallel with a rabbit toxicology study. These studies demonstrated that the vaccine did not induce abnormal pathology. We also show that in mice the vaccine is highly immunogenic but that 3 doses are required to induce protection from a GAS skin challenge even though 2 doses are sufficient to induce a high antibody titer. PMID:27541593

  14. Preclinical immunogenicity and safety of a Group A streptococcal M protein-based vaccine candidate.

    PubMed

    Batzloff, Michael R; Fane, Anne; Gorton, Davina; Pandey, Manisha; Rivera-Hernandez, Tania; Calcutt, Ainslie; Yeung, Grace; Hartas, Jon; Johnson, Linda; Rush, Catherine M; McCarthy, James; Ketheesan, Natkunam; Good, Michael F

    2016-12-01

    Streptococcus pyogenes (group A streptococcus, GAS) causes a wide range of clinical manifestations ranging from mild self-limiting pyoderma to invasive diseases such as sepsis. Also of concern are the post-infectious immune-mediated diseases including rheumatic heart disease. The development of a vaccine against GAS would have a large health impact on populations at risk of these diseases. However, there is a lack of suitable models for the safety evaluation of vaccines with respect to post-infectious complications. We have utilized the Lewis Rat model for cardiac valvulitis to evaluate the safety of the J8-DT vaccine formulation in parallel with a rabbit toxicology study. These studies demonstrated that the vaccine did not induce abnormal pathology. We also show that in mice the vaccine is highly immunogenic but that 3 doses are required to induce protection from a GAS skin challenge even though 2 doses are sufficient to induce a high antibody titer.

  15. Preclinical safety assessments of nano-sized constructs on cardiovascular system toxicity: A case for telemetry.

    PubMed

    Cheah, Hoay Yan; Kiew, Lik Voon; Lee, Hong Boon; Japundžić-Žigon, Nina; Vicent, Marίa J; Hoe, See Ziau; Chung, Lip Yong

    2017-11-01

    While nano-sized construct (NSC) use in medicine has grown significantly in recent years, reported unwanted side effects have raised safety concerns. However, the toxicity of NSCs to the cardiovascular system (CVS) and the relative merits of the associated evaluation methods have not been thoroughly studied. This review discusses the toxicological profiles of selected NSCs and provides an overview of the assessment methods, including in silico, in vitro, ex vivo and in vivo models and how they are related to CVS toxicity. We conclude the review by outlining the merits of telemetry coupled with spectral analysis, baroreceptor reflex sensitivity analysis and echocardiography as an appropriate integrated strategy for the assessment of the acute and chronic impact of NSCs on the CVS. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Chronic Electrical Stimulation with a Suprachoroidal Retinal Prosthesis: A Preclinical Safety and Efficacy Study

    PubMed Central

    Nayagam, David A. X.; Williams, Richard A.; Allen, Penelope J.; Shivdasani, Mohit N.; Luu, Chi D.; Salinas-LaRosa, Cesar M.; Finch, Sue; Ayton, Lauren N.; Saunders, Alexia L.; McPhedran, Michelle; McGowan, Ceara; Villalobos, Joel; Fallon, James B.; Wise, Andrew K.; Yeoh, Jonathan; Xu, Jin; Feng, Helen; Millard, Rodney; McWade, Melanie; Thien, Patrick C.; Williams, Chris E.; Shepherd, Robert K.

    2014-01-01

    Purpose To assess the safety and efficacy of chronic electrical stimulation of the retina with a suprachoroidal visual prosthesis. Methods Seven normally-sighted feline subjects were implanted for 96–143 days with a suprachoroidal electrode array and six were chronically stimulated for 70–105 days at levels that activated the visual cortex. Charge balanced, biphasic, current pulses were delivered to platinum electrodes in a monopolar stimulation mode. Retinal integrity/function and the mechanical stability of the implant were assessed monthly using electroretinography (ERG), optical coherence tomography (OCT) and fundus photography. Electrode impedances were measured weekly and electrically-evoked visual cortex potentials (eEVCPs) were measured monthly to verify that chronic stimuli were suprathreshold. At the end of the chronic stimulation period, thresholds were confirmed with multi-unit recordings from the visual cortex. Randomized, blinded histological assessments were performed by two pathologists to compare the stimulated and non-stimulated retina and adjacent tissue. Results All subjects tolerated the surgical and stimulation procedure with no evidence of discomfort or unexpected adverse outcomes. After an initial post-operative settling period, electrode arrays were mechanically stable. Mean electrode impedances were stable between 11–15 kΩ during the implantation period. Visually-evoked ERGs & OCT were normal, and mean eEVCP thresholds did not substantially differ over time. In 81 of 84 electrode-adjacent tissue samples examined, there were no discernible histopathological differences between stimulated and unstimulated tissue. In the remaining three tissue samples there were minor focal fibroblastic and acute inflammatory responses. Conclusions Chronic suprathreshold electrical stimulation of the retina using a suprachoroidal electrode array evoked a minimal tissue response and no adverse clinical or histological findings. Moreover, thresholds and

  17. Preclinical assessment of safety of maternal vaccination against respiratory syncytial virus (RSV) in cotton rats.

    PubMed

    Blanco, Jorge C G; Pletneva, Lioubov M; Otoa, Raymonde O; Patel, Mira C; Vogel, Stefanie N; Boukhvalova, Marina S

    2017-07-13

    Maternal immunization directed to control RSV infection in newborns and infants is an appealing vaccination strategy currently under development. In this work we have modeled maternal vaccination against RSV in cotton rats (CR) to answer two fundamental questions on maternal vaccine safety. We tested (i), whether a known, unsafe RSV vaccine (i.e., FI-RSV Lot 100 vaccine) induces vaccine enhanced disease in the presence of passively transferred, RSV maternal immunity, and (ii) whether the same FI-RSV vaccine could induce vaccine enhanced disease in CR litters when used to immunize their RSV-primed mothers. Our data show that FI-RSV immunization of pups with subsequent RSV infection results in vaccine-enhanced disease independent of whether the pups were born to RSV-seropositive or RSV-seronegative mothers, and that FI-RSV immunization of RSV-seropositive mothers does not present a health risk to either the mother or the infant. Our study also raises a novel concern regarding infant immunization, namely that "safe" RSV vaccines (e.g., live RSV administered intramuscularly) may induce vaccine-enhanced disease in RSV-infected pups born to seropositive mothers. Finally, we describe for the first time a sharp decrease in RSV neutralizing antibody titers in immunized seropositive CR at the time of delivery. This decline may reflect maternal immune suppression, potentially pinpointing a window of increased vulnerability to RSV infection that could be alleviated by effective immunization of expectant mothers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. The Use of Minipigs for Preclinical Safety Assessment by the Pharmaceutical Industry: Results of an IQ DruSafe Minipig Survey.

    PubMed

    Colleton, Curtis; Brewster, David; Chester, Anne; Clarke, David O; Heining, Peter; Olaharski, Andrew; Graziano, Michael

    2016-04-01

    The use of minipigs in preclinical safety testing of pharmaceuticals is considered an alternative to the more traditional dog and nonhuman primate (NHP) nonrodent species. Substantial evidence exists to suggest that the anatomy, physiology, and biochemistry of minipigs are similar enough to humans to consider them as valid nonrodent models for pharmaceutical safety testing. Since the utilization of minipigs was last assessed over 5 years ago, the Preclinical Safety Leadership Group (DruSafe) of the International Consortium for Innovation and Quality in Pharmaceutical Development conducted this survey to provide an updated assessment of the utility, perceived value, and impediments to the use of minipigs in preclinical safety testing. Of the 32 participating members of DruSafe, 15 responded to the survey representing both large and small companies. Respondents indicated that the minipig has been utilized mostly for short-term safety assessment studies with dermal, oral, and parenteral routes of administration. Minipigs are widely accepted as appropriate models for cardiovascular assessments and have been used to a limited extent for reproductive toxicology testing. Overall responses indicated that safety testing for large molecules using this species is relatively low due to a lack of background data, reagents or biomarkers, concerns regarding immune system characterization and poor suitability for developmental toxicity assessments. Most companies utilized contract research organizations for definitive safety toxicity assessment studies. Conclusions of this survey indicate that minipig is an acceptable nonrodent species largely limited to studies using small molecules, primarily dermal products, and results are comparable to those reported 5 years ago. © The Author(s) 2016.

  19. Aerosol gemcitabine: preclinical safety and in vivo antitumor activity in osteosarcoma-bearing dogs.

    PubMed

    Rodriguez, Carlos O; Crabbs, Torrie A; Wilson, Dennis W; Cannan, Virginia A; Skorupski, Katherine A; Gordon, Nancy; Koshkina, Nadya; Kleinerman, Eugenie; Anderson, Peter M

    2010-08-01

    Osteosarcoma is the most common skeletal malignancy in the dog and in young humans. Although chemotherapy improves survival time, death continues to be attributed to metastases. Aerosol delivery can provide a strategy with which to improve the lung drug delivery while reducing systemic toxicity. The purpose of this study is to assess the safety of a regional aerosol approach to chemotherapy delivery in osteosarcoma-bearing dogs, and second, to evaluate the effect of gemcitabine on Fas expression in the pulmonary metastasis. We examined the systemic and local effects of aerosol gemcitabine on lung and pulmonary metastasis in this relevant large-animal tumor model using serial laboratory and arterial blood gas analysis and histopathology and immunohistochemistry, respectively. Six hundred seventy-two 1-h doses of aerosol gemcitabine were delivered. The treatment was well tolerated by these subjects with osteosarcoma (n = 20). Aerosol-treated subjects had metastatic foci that demonstrated extensive, predominately central, intratumoral necrosis. Fas expression was decreased in pulmonary metastases compared to the primary tumor (p = 0.008). After aerosol gemcitabine Fas expression in the metastatic foci was increased compared to lung metastases before treatment (p = 0.0075), and even was higher than the primary tumor (p = 0.025). Increased apoptosis (TUNEL) staining was also detected in aerosol gemcitabine treated metastasis compared to untreated controls (p = 0.028). The results from this pivotal translational study support the concept that aerosol gemcitabine may be useful against pulmonary metastases of osteosarcoma. Additional studies that evaluate the aerosol route of administration of gemcitabine in humans should be safe and are warranted.

  20. Aerosol Gemcitabine: Preclinical Safety and In Vivo Antitumor Activity in Osteosarcoma-Bearing Dogs

    PubMed Central

    Crabbs, Torrie A.; Wilson, Dennis W.; Cannan, Virginia A.; Skorupski, Katherine A.; Gordon, Nancy; Koshkina, Nadya; Kleinerman, Eugenie; Anderson, Peter M.

    2010-01-01

    Abstract Background Osteosarcoma is the most common skeletal malignancy in the dog and in young humans. Although chemotherapy improves survival time, death continues to be attributed to metastases. Aerosol delivery can provide a strategy with which to improve the lung drug delivery while reducing systemic toxicity. The purpose of this study is to assess the safety of a regional aerosol approach to chemotherapy delivery in osteosarcoma-bearing dogs, and second, to evaluate the effect of gemcitabine on Fas expression in the pulmonary metastasis. Methods We examined the systemic and local effects of aerosol gemcitabine on lung and pulmonary metastasis in this relevant large-animal tumor model using serial laboratory and arterial blood gas analysis and histopathology and immunohistochemistry, respectively. Results and Conclusions Six hundred seventy-two 1-h doses of aerosol gemcitabine were delivered. The treatment was well tolerated by these subjects with osteosarcoma (n = 20). Aerosol-treated subjects had metastatic foci that demonstrated extensive, predominately central, intratumoral necrosis. Fas expression was decreased in pulmonary metastases compared to the primary tumor (p = 0.008). After aerosol gemcitabine Fas expression in the metastatic foci was increased compared to lung metastases before treatment (p = 0.0075), and even was higher than the primary tumor (p = 0.025). Increased apoptosis (TUNEL) staining was also detected in aerosol gemcitabine treated metastasis compared to untreated controls (p = 0.028). The results from this pivotal translational study support the concept that aerosol gemcitabine may be useful against pulmonary metastases of osteosarcoma. Additional studies that evaluate the aerosol route of administration of gemcitabine in humans should be safe and are warranted. PMID:19803732

  1. Preclinical Mammalian Safety Studies of EPHARNA (DOPC Nanoliposomal EphA2-Targeted siRNA).

    PubMed

    Wagner, Michael J; Mitra, Rahul; McArthur, Mark J; Baze, Wallace; Barnhart, Kirstin; Wu, Sherry Y; Rodriguez-Aguayo, Cristian; Zhang, Xinna; Coleman, Robert L; Lopez-Berestein, Gabriel; Sood, Anil K

    2017-06-01

    To address the need for efficient and biocompatible delivery systems for systemic siRNA delivery, we developed 1,2-Dioleoyl-sn-Glycero-3-Phosphatidylcholine (DOPC) nanoliposomal EphA2-targeted therapeutic (EPHARNA). Here, we performed safety studies of EPHARNA in murine and primate models. Single dosing of EPHARNA was tested at 5 concentrations in mice ( N = 15 per group) and groups were sacrificed on days 1, 14, and 28 for evaluation of clinical pathology and organ toxicity. Multiple dosing of EPHARNA was tested in mice and Rhesus macaques twice weekly at two dose levels in each model. Possible effects on hematologic parameters, serum chemistry, coagulation, and organ toxicity were assessed. Following single-dose EPHARNA administration to mice, no gross pathologic or dose-related microscopic findings were observed in either the acute (24 hours) or recovery (14 and 28 days) phases. The no-observed-adverse-effect level (NOAEL) for EPHARNA is considered >225 μg/kg when administered as a single injection intravenously in CD-1 mice. With twice weekly injection, EPHARNA appeared to stimulate a mild to moderate inflammatory response in a dose-related fashion. There appeared to be a mild hemolytic reaction in the female mice. In Rhesus macaques, minimal to moderate infiltration of mononuclear cells was found in some organs including the gastrointestinal tract, heart, and kidney. No differences attributed to EPHARNA were observed. These results demonstrate that EPHARNA is well tolerated at all doses tested. These data, combined with previously published in vivo validation studies, have led to an ongoing first-in-human phase I clinical trial (NCT01591356). Mol Cancer Ther; 16(6); 1114-23. ©2017 AACR . ©2017 American Association for Cancer Research.

  2. Preclinical Efficacy and Safety Assessment of Artemisinin-Chemotherapeutic Agent Conjugates for Ovarian Cancer.

    PubMed

    Li, Xiaoguang; Zhou, Yu; Liu, Yanling; Zhang, Xu; Chen, Tao; Chen, Kerong; Ba, Qian; Li, Jingquan; Liu, Hong; Wang, Hui

    2016-12-01

    Artemisinin (ARS) and its derivatives, which are clinically used antimalarial agents, have shown antitumor activities. Their therapeutic potencies, however, are limited by their low solubility and poor bioavailability. Here, through a pharmacophore hybridization strategy, we synthesized ARS-drug conjugates, in which the marketed chemotherapeutic agents chlorambucil, melphalan, flutamide, aminoglutethimide, and doxifluridine, were separately bonded to Dihydroartemisinin (DHA) through various linkages. Of these, the artemisinin-melphalan conjugate, ARS4, exhibited most toxicity to human ovarian cancer cells but had low cytotoxicity to normal cells. ARS4 inhibited the growth and proliferation of ovarian cancer cells and resulted in S-phase arrest, apoptosis, and inhibition of migration; these effects were stronger than those of its parent drugs, DHA and melphalan. Furthermore, ARS4 modulated the expression of proteins involved in cell cycle progression, apoptosis, and the epithelial-mesenchymal transition (EMT). Moreover, in mice, ARS4 inhibited growth and intraperitoneal dissemination and metastasis of ovarian cancer cells without observable toxic effects. Our results provide a basis for development of the compound as a chemotherapeutic agent. Artemisinin compounds have recently received attention as anticancer agents because of their clinical safety profiles and broad efficacy. However, their therapeutic potencies are limited by low solubility and poor bioavailability. Here, we report that ARS4, an artemisinin-melphalan conjugate, possesses marked in-vitro and in-vivo antitumor activity against ovarian cancer, the effects of which are stronger than those for its parent drugs, Dihydroartemisinin and melphalan. In mice, ARS4 inhibits localized growth of ovarian cancer cells and intraperitoneal dissemination and metastasis without appreciable host toxicity. Thus, for patients with ovarian cancer, ARS4 is a promising chemotherapeutic agent. Copyright © 2016 The Authors

  3. An integrated approach to improved toxicity prediction for the safety assessment during preclinical drug development using Hep G2 cells

    SciTech Connect

    Noor, Fozia; Niklas, Jens; Mueller-Vieira, Ursula

    2009-06-01

    Efficient and accurate safety assessment of compounds is extremely important in the preclinical development of drugs especially when hepatotoxicty is in question. Multiparameter and time resolved assays are expected to greatly improve the prediction of toxicity by assessing complex mechanisms of toxicity. An integrated approach is presented in which Hep G2 cells and primary rat hepatocytes are compared in frequently used cytotoxicity assays for parent compound toxicity. The interassay variability was determined. The cytotoxicity assays were also compared with a reliable alternative time resolved respirometric assay. The set of training compounds consisted of well known hepatotoxins; amiodarone, carbamazepine, clozapine, diclofenac,more » tacrine, troglitazone and verapamil. The sensitivity of both cell systems in each tested assay was determined. Results show that careful selection of assay parameters and inclusion of a kinetic time resolved assay improves prediction for non-metabolism mediated toxicity using Hep G2 cells as indicated by a sensitivity ratio of 1. The drugs with EC{sub 50} values 100 {mu}M or lower were considered toxic. The difference in the sensitivity of the two cell systems to carbamazepine which causes toxicity via reactive metabolites emphasizes the importance of human cell based in-vitro assays. Using the described system, primary rat hepatocytes do not offer advantage over the Hep G2 cells in parent compound toxicity evaluation. Moreover, respiration method is non invasive, highly sensitive and allows following the time course of toxicity. Respiration assay could serve as early indicator of changes that subsequently lead to toxicity.« less

  4. Saporin-S6: A Useful Tool in Cancer Therapy

    PubMed Central

    Polito, Letizia; Bortolotti, Massimo; Mercatelli, Daniele; Battelli, Maria Giulia; Bolognesi, Andrea

    2013-01-01

    Thirty years ago, the type 1 ribosome-inactivating protein (RIP) saporin-S6 (also known as saporin) was isolated from Saponaria officinalis L. seeds. Since then, the properties and mechanisms of action of saporin-S6 have been well characterized, and it has been widely employed in the construction of conjugates and immunotoxins for different purposes. These immunotoxins have shown many interesting results when used in cancer therapy, particularly in hematological tumors. The high enzymatic activity, stability and resistance to conjugation procedures and blood proteases make saporin-S6 a very useful tool in cancer therapy. High efficacy has been reported in clinical trials with saporin-S6-containing immunotoxins, at dosages that induced only mild and transient side effects, which were mainly fever, myalgias, hepatotoxicity, thrombocytopenia and vascular leak syndrome. Moreover, saporin-S6 triggers multiple cell death pathways, rendering impossible the selection of RIP-resistant mutants. In this review, some aspects of saporin-S6, such as the chemico-physical characteristics, the structural properties, its endocytosis, its intracellular routing and the pathogenetic mechanisms of the cell damage, are reported. In addition, the recent progress and developments of saporin-S6-containing immunotoxins in cancer immunotherapy are summarized, including in vitro and in vivo pre-clinical studies and clinical trials. PMID:24105401

  5. Preclinical Biodistribution and Safety Evaluation of a pbi-shRNA STMN1 Lipoplex after Subcutaneous Delivery.

    PubMed

    Wang, Zhaohui; Jay, Christopher M; Evans, Courtney; Kumar, Padmasini; Phalon, Connor; Rao, Donald D; Senzer, Neil; Nemunaitis, John

    2017-02-01

    Stathmin-1 (STMN1) is a microtubule-destabilizing protein which is overexpressed in cancer. Its overexpression is associated with poor prognosis and also serves as a predictive marker to taxane therapy. We have developed a proprietary bi-functional shRNA (bi-shRNA) platform to execute RNA interference (RNAi)-mediated gene silencing and a liposome-carrier complex to systemically deliver the pbi-shRNA plasmids. In vitro and in vivo testing demonstrated efficacy and specificity of pbi-shRNA plasmid in targeting STMN1 (Phadke, A. P., Jay, C. M., Wang, Z., Chen, S., Liu, S., Haddock, C., Kumar, P., Pappen, B. O., Rao, D. D., Templeton, N. S., et al. (2011). In vivo safety and antitumor efficacy of bifunctional small hairpin RNAs specific for the human Stathmin 1 oncoprotein. DNA Cell Biol. 30, 715-726.). Biodistribution and toxicology studies in bio-relevant Sprague Dawley rats with pbi-shRNA STMN1 lipoplex revealed that the plasmid DNA was delivered to a broad distribution of organs after a single subcutaneous injection. Specifically, plasmid was detected within the first week using QPCR (threshold 50 copies plasmid/1 µg genomic DNA) at the injection site, lung, spleen, blood, skin, ovary (limited), lymph nodes, and liver. It was not detected in the heart, testis or bone marrow. No plasmid was detected from any organ 30 days after injection. Treatment was well tolerated. Minimal inflammation/erythema was observed at the injection site. Circulating cytokine response was also examined by ELISA. The IL-6 levels were induced within 6 h then declined to the vehicle control level 72 h after the injection. TNFα induction was transiently observed 4 days after the DNA lipoplex treatment. In summary, the pbi-shRNA STMN1 lipoplex was well tolerated and displayed broad distribution after a single subcutaneous injection. The pre-clinical data has been filed to FDA and the pbi-shRNA STMN1 lipoplex is being investigated in a phase I clinical study. © The Author 2016. Published

  6. Determination of exposure multiples of human metabolites for MIST assessment in preclinical safety species without using reference standards or radiolabeled compounds.

    PubMed

    Ma, Shuguang; Li, Zhiling; Lee, Keun-Joong; Chowdhury, Swapan K

    2010-12-20

    A simple, reliable, and accurate method was developed for quantitative assessment of metabolite coverage in preclinical safety species by mixing equal volumes of human plasma with blank plasma of animal species and vice versa followed by an analysis using high-resolution full-scan accurate mass spectrometry. This approach provided comparable results (within (±15%) to those obtained from regulated bioanalysis and did not require synthetic standards or radiolabeled compounds. In addition, both qualitative and quantitative data were obtained from a single LC-MS analysis on all metabolites and, therefore, the coverage of any metabolite of interest can be obtained.

  7. System Vaccinology for the Evaluation of Influenza Vaccine Safety by Multiplex Gene Detection of Novel Biomarkers in a Preclinical Study and Batch Release Test

    PubMed Central

    Mizukami, Takuo; Momose, Haruka; Kuramitsu, Madoka; Takizawa, Kazuya; Araki, Kumiko; Furuhata, Keiko; Ishii, Ken J.; Hamaguchi, Isao; Yamaguchi, Kazunari

    2014-01-01

    Vaccines are beneficial and universal tools to prevent infectious disease. Thus, safety of vaccines is strictly evaluated in the preclinical phase of trials and every vaccine batch must be tested by the National Control Laboratories according to the guidelines published by each country. Despite many vaccine production platforms and methods, animal testing for safety evaluation is unchanged thus far. We recently developed a systems biological approach to vaccine safety evaluation where identification of specific biomarkers in a rat pre-clinical study evaluated the safety of vaccines for pandemic H5N1 influenza including Irf7, Lgals9, Lgalsbp3, Cxcl11, Timp1, Tap2, Psmb9, Psme1, Tapbp, C2, Csf1, Mx2, Zbp1, Ifrd1, Trafd1, Cxcl9, β2m, Npc1, Ngfr and Ifi47. The current study evaluated whether these 20 biomarkers could evaluate the safety, batch-to-batch and manufacturer-to-manufacturer consistency of seasonal trivalent influenza vaccine using a multiplex gene detection system. When we evaluated the influenza HA vaccine (HAv) from four different manufactures, the biomarker analysis correlated to findings from conventional animal use tests, such as abnormal toxicity test. In addition, sensitivity of toxicity detection and differences in HAvs were higher and more accurate than with conventional methods. Despite a slight decrease in body weight caused by HAv from manufacturer B that was not statistically significant, our results suggest that HAv from manufacturer B is significantly different than the other HAvs tested with regard to Lgals3bp, Tapbp, Lgals9, Irf7 and C2 gene expression in rat lungs. Using the biomarkers confirmed in this study, we predicted batch-to-batch consistency and safety of influenza vaccines within 2 days compared with the conventional safety test, which takes longer. These biomarkers will facilitate the future development of new influenza vaccines and provide an opportunity to develop in vitro methods of evaluating batch-to-batch consistency and

  8. Essentials for starting a pediatric clinical study (4): Clinical pediatric safety planning based on preclinical toxicity studies and pediatric pharmacovigilance guidance.

    PubMed

    Sheth, Neha

    2009-01-01

    Juvenile toxicology studies in animals provide useful information to guide monitoring of potential adverse effects in children especially on growth and development. In order to continue to gain knowledge and build upon these preclinical studies, recent experience has suggested that additional approaches for monitoring of safety concerns in the pediatric population may be required. Recently, pediatric guidance has become available from the health authorities which provide pharmacovigilance concepts as they specifically relate to drugs being developed for pediatric indications. Clinical trials are typically not robust enough to detect rare or delayed safety effects as the pediatric trials are relatively short-term. Furthermore, such long term or rare effects may not be detected via standard voluntary postmarketing surveillance. Safety monitoring of children with Juvenile Inflammatory Arthritis (JIA) taking nonsteroid anti-inflammatory drug (NSAID)s will be used as an example to describe a post-marketing risk management and pharmacovigilance program that serves to better evaluate safety data from various sources. The intent of this program is to identify adverse events (AE), including events with longer latency, which may be associated with NSAID use in a pediatric population. In this presentation, the 4 major components of the program are to be addressed. Such a program may serve as a model to proactively generate and monitor safety data in order to identify AEs that may be associated with new therapeutics for a pediatric population.

  9. Preclinical Pharmacokinetics and First-in-Human Pharmacokinetics, Safety, and Tolerability of Velpatasvir, a Pangenotypic Hepatitis C Virus NS5A Inhibitor, in Healthy Subjects

    PubMed Central

    German, Polina; Kearney, Brian P.; Yang, Cheng Yong; Brainard, Diana; Link, John; McNally, John; Han, LingLing; Ling, John; Mathias, Anita

    2017-01-01

    ABSTRACT Preclinical characterization of velpatasvir (VEL; GS-5816), an inhibitor of the hepatitis C virus (HCV) NS5A protein, demonstrated that it has favorable in vitro and in vivo properties, including potent antiviral activity against hepatitis C virus genotype 1 to 6 replicons, good metabolic stability, low systemic clearance, and adequate bioavailability and physicochemical properties, to warrant clinical evaluation. The phase 1 (first-in-human) study evaluated the safety, tolerability, and pharmacokinetics of VEL in healthy human subjects following administration of single and multiple (n = 7) once-daily ascending doses and of VEL in the presence and absence of food. Following administration of single and multiple doses, VEL was safe and well tolerated when administered at up to 450 mg and when administered with food. The pharmacokinetic behavior of VEL observed in humans was generally in agreement with that seen during preclinical characterization. Following administration of multiple doses, VEL trough concentrations were significantly greater than the protein-adjusted half-maximal (50%) effective concentration of VEL against HCV genotype 1 to 6 replicons at all evaluated doses greater than 5 mg. The pharmacokinetics of VEL were not significantly affected by administration with food. Collectively, the results of this study support the further clinical investigation of VEL administered once daily as part of a regimen with other pangenotypic direct-acting antivirals for the treatment of HCV infection. PMID:28193657

  10. Preclinical Assessment of CD171-Directed CAR T-cell Adoptive Therapy for Childhood Neuroblastoma: CE7 Epitope Target Safety and Product Manufacturing Feasibility.

    PubMed

    Künkele, Annette; Taraseviciute, Agne; Finn, Laura S; Johnson, Adam J; Berger, Carolina; Finney, Olivia; Chang, Cindy A; Rolczynski, Lisa S; Brown, Christopher; Mgebroff, Stephanie; Berger, Michael; Park, Julie R; Jensen, Michael C

    2017-01-15

    The identification and vetting of cell surface tumor-restricted epitopes for chimeric antigen receptor (CAR)-redirected T-cell immunotherapy is the subject of intensive investigation. We have focused on CD171 (L1-CAM), an abundant cell surface molecule on neuroblastomas and, specifically, on the glycosylation-dependent tumor-specific epitope recognized by the CE7 monoclonal antibody. CD171 expression was assessed by IHC using CE7 mAb in tumor microarrays of primary, metastatic, and recurrent neuroblastoma, as well as human and rhesus macaque tissue arrays. The safety of targeting the CE7 epitope of CD171 with CE7-CAR T cells was evaluated in a preclinical rhesus macaque trial on the basis of CD171 homology and CE7 cross reactivity. The feasibility of generating bioactive CAR T cells from heavily pretreated pediatric patients with recurrent/refractory disease was assessed. CD171 is uniformly and abundantly expressed by neuroblastoma tumor specimens obtained at diagnoses and relapse independent of patient clinical risk group. CD171 expression in normal tissues is similar in humans and rhesus macaques. Infusion of up to 1 × 10 8 /kg CE7-CAR + CTLs in rhesus macaques revealed no signs of specific on-target off-tumor toxicity. Manufacturing of lentivirally transduced CD4 + and CD8 + CE7-CAR T-cell products under GMP was successful in 4 out of 5 consecutively enrolled neuroblastoma patients in a phase I study. All four CE7-CAR T-cell products demonstrated in vitro and in vivo antitumor activity. Our preclinical assessment of the CE7 epitope on CD171 supports its utility and safety as a CAR T-cell target for neuroblastoma immunotherapy. Clin Cancer Res; 23(2); 466-77. ©2016 AACR. ©2016 American Association for Cancer Research.

  11. Preclinical efficacy and safety of an anti-IL-1β vaccine for the treatment of type 2 diabetes

    PubMed Central

    Spohn, Gunther; Schori, Christian; Keller, Iris; Sladko, Katja; Sina, Christina; Guler, Reto; Schwarz, Katrin; Johansen, Pål; Jennings, Gary T; Bachmann, Martin F

    2014-01-01

    Neutralization of the inflammatory cytokine interleukin-1β (IL-1β) is a promising new strategy to prevent the β-cell destruction, which leads to type 2 diabetes. Here, we describe the preclinical development of a therapeutic vaccine against IL-1β consisting of a detoxified version of IL-1β chemically cross-linked to virus-like particles of the bacteriophage Qβ. The vaccine was well tolerated and induced robust antibody responses in mice, which neutralized the biological activity of IL-1β, as shown both in cellular assays and in challenge experiments in vivo. Antibody titers were long lasting but reversible over time and not associated with the development of potentially harmful T cell responses against IL-1β. Neutralization of IL-1β by vaccine-induced antibodies had no influence on the immune responses of mice to Listeria monocytogenes and Mycobacterium tuberculosis. In a diet-induced model of type 2 diabetes, immunized mice showed improved glucose tolerance, which was mediated by improved insulin secretion by pancreatic β-cells. Hence, immunization with IL-1β conjugated to virus-like particles has the potential to become a safe, efficacious, and cost-effective therapy for the prevention and long-term treatment of type 2 diabetes. PMID:26015986

  12. Safety data on 19 vehicles for use in 1 month oral rodent pre-clinical studies: administration of hydroxypropyl-ß-cyclodextrin causes renal toxicity.

    PubMed

    Healing, Guy; Sulemann, Tabassum; Cotton, Peter; Harris, Jayne; Hargreaves, Adam; Finney, Rowena; Kirk, Sarah; Schramm, Carolin; Garner, Clare; Pivette, Perrine; Burdett, Lisa

    2016-01-01

    Potential new drugs are assessed in pre-clinical in vivo studies to determine their safety profiles. The drugs are formulated in vehicles suitable for the route of administration and the physicochemical properties of the drug, aiming to achieve optimal exposure in the test species. The availability of safety data on vehicles is often limited (incomplete data, access restricted/private databases). Nineteen potentially useful vehicles that contained new and/or increased concentrations of excipients and for which little safety data have been published were tested. Vehicles were dosed orally once daily to HanWistar rats for a minimum of 28 days and a wide range of toxicological parameters were assessed. Only 30% (w/v) hydroxypropyl-ß-cyclodextrin was found unsuitable owing to effects on liver enzymes (AST, ALT and GLDH), urinary volume and the kidneys (tubular vacuolation and tubular pigment). 20% (v/v) oleic acid caused increased salivation and hence this vehicle should be used with caution. As 40% (v/v) tetraethylene glycol affected urinary parameters, its use should be carefully considered, particularly for compounds suspected to impact the renal system and studies longer than 1 month. There were no toxicologically significant findings with 10% (v/v) dimethyl sulphoxide, 20% (v/v) propylene glycol, 33% (v/v) Miglyol®812, 20% (w/v) Kolliphor®RH40, 10% (w/v) Poloxamer 407, 5% (w/v) polyvinylpyrrolidone K30 or 10% (v/v) Labrafil®M1944. All other vehicles tested caused isolated or low magnitude effects which would not prevent their use. The aim of sharing these data, including adverse findings, is to provide meaningful information for vehicle selection, thereby avoiding repetition of animal experimentation. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Pre-Clinical Efficacy and Safety of Experimental Vaccines Based on Non-Replicating Vaccinia Vectors against Yellow Fever

    PubMed Central

    Schäfer, Birgit; Holzer, Georg W.; Joachimsthaler, Alexandra; Coulibaly, Sogue; Schwendinger, Michael; Crowe, Brian A.; Kreil, Thomas R.; Barrett, P. Noel; Falkner, Falko G.

    2011-01-01

    Background Currently existing yellow fever (YF) vaccines are based on the live attenuated yellow fever virus 17D strain (YFV-17D). Although, a good safety profile was historically attributed to the 17D vaccine, serious adverse events have been reported, making the development of a safer, more modern vaccine desirable. Methodology/Principal Findings A gene encoding the precursor of the membrane and envelope (prME) protein of the YFV-17D strain was inserted into the non-replicating modified vaccinia virus Ankara and into the D4R-defective vaccinia virus. Candidate vaccines based on the recombinant vaccinia viruses were assessed for immunogenicity and protection in a mouse model and compared to the commercial YFV-17D vaccine. The recombinant live vaccines induced γ-interferon-secreting CD4- and functionally active CD8-T cells, and conferred full protection against lethal challenge already after a single low immunization dose of 105 TCID50. Surprisingly, pre-existing immunity against wild-type vaccinia virus did not negatively influence protection. Unlike the classical 17D vaccine, the vaccinia virus-based vaccines did not cause mortality following intracerebral administration in mice, demonstrating better safety profiles. Conclusions/Significance The non-replicating recombinant YF candidate live vaccines induced a broad immune response after single dose administration, were effective even in the presence of a pre-existing immunity against vaccinia virus and demonstrated an excellent safety profile in mice. PMID:21931732

  14. Pre-clinical efficacy and safety of experimental vaccines based on non-replicating vaccinia vectors against yellow fever.

    PubMed

    Schäfer, Birgit; Holzer, Georg W; Joachimsthaler, Alexandra; Coulibaly, Sogue; Schwendinger, Michael; Crowe, Brian A; Kreil, Thomas R; Barrett, P Noel; Falkner, Falko G

    2011-01-01

    Currently existing yellow fever (YF) vaccines are based on the live attenuated yellow fever virus 17D strain (YFV-17D). Although, a good safety profile was historically attributed to the 17D vaccine, serious adverse events have been reported, making the development of a safer, more modern vaccine desirable. A gene encoding the precursor of the membrane and envelope (prME) protein of the YFV-17D strain was inserted into the non-replicating modified vaccinia virus Ankara and into the D4R-defective vaccinia virus. Candidate vaccines based on the recombinant vaccinia viruses were assessed for immunogenicity and protection in a mouse model and compared to the commercial YFV-17D vaccine. The recombinant live vaccines induced γ-interferon-secreting CD4- and functionally active CD8-T cells, and conferred full protection against lethal challenge already after a single low immunization dose of 10(5) TCID(50). Surprisingly, pre-existing immunity against wild-type vaccinia virus did not negatively influence protection. Unlike the classical 17D vaccine, the vaccinia virus-based vaccines did not cause mortality following intracerebral administration in mice, demonstrating better safety profiles. The non-replicating recombinant YF candidate live vaccines induced a broad immune response after single dose administration, were effective even in the presence of a pre-existing immunity against vaccinia virus and demonstrated an excellent safety profile in mice.

  15. Initial preclinical safety of non-replicating human endogenous retrovirus envelope protein-coated baculovirus vector-based vaccines against human papillomavirus.

    PubMed

    Han, Su-Eun; Kim, Mi-Gyeong; Lee, Soondong; Cho, Hee-Jeong; Byun, Youngro; Kim, Sujeong; Kim, Young Bong; Choi, Yongseok; Oh, Yu-Kyoung

    2013-12-01

    Human endogenous retrovirus (HERV) envelope protein-coated, baculovirus vector-based HPV 16 L1 (AcHERV-HPV16L1) is a non-replicating recombinant baculoviral vaccine. Here, we report an initial evaluation of the preclinical safety of AcHERV-HPV16L1 vaccine. In an acute toxicity study, a single administration of AcHERV-HPV16L1 DNA vaccine given intramuscularly (i.m.) to mice at a dose of 1 × 10(8) plaque-forming units (PFU) did not cause significant changes in body weight compared with vehicle-treated controls. It did cause a brief increase in the weights of some organs on day 15 post-treatment, but by day 30, all organ weights were not significantly different from those in the vehicle-treated control group. No hematological changes were observed on day 30 post-treatment. In a range-finding toxicity study with three doses of 1 × 10(7) , 2 × 10(7) and 5 × 10(7) PFU once daily for 5 days, the group treated with 5 × 10(7) PFU showed a transient decrease in the body weights from day 5 to day 15 post-treatment, but recovery to the levels similar to those in the vehicle-treated control group by post-treatment day 20. Organ weights were slightly higher for lymph nodes, spleen, thymus and liver after repeated dosing with 5 × 10(7) PFU on day 15, but had normalized by day 30. Moreover, repeated administration of AcHERV-HPV16L1 did not induce myosin-specific autoantibody in serum, and did not cause immune complex deposition or tissue damage at injection sites. Taken together, these results provide preliminary evidence of the preclinical safety of AcHERV-based HPV16L1 DNA vaccines in mice. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Preclinical safety assessment of the 5-HT2A receptor agonist PET radioligand [ 11C]Cimbi-36.

    PubMed

    Ettrup, Anders; Holm, Søren; Hansen, Martin; Wasim, Muhammad; Santini, Martin Andreas; Palner, Mikael; Madsen, Jacob; Svarer, Claus; Kristensen, Jesper Langgaard; Knudsen, Gitte Moos

    2013-08-01

    [11C]Cimbi-36 was recently developed as an agonist radioligand for brain imaging of serotonin 2A receptors (5-HT2A) with positron emission tomography (PET). This may be used to quantify the high-affinity state of 5-HT2A receptors and may have the potential to quantify changes in cerebral 5-HT levels in vivo. We here investigated safety aspects related to clinical use of [11C]Cimbi-36, including radiation dosimetry and in vivo pharmacology. [11C]Cimbi-36 was injected in rats or pigs, and radiation dosimetry was examined by ex vivo dissection or with PET scanning, respectively. Based on animal data, the Organ Level INternal Dose Assessment software was used to estimate extrapolated human dosimetry for [11C]Cimbi-36. The 5-HT2A receptor agonist actions of [11C]Cimbi-36 in vivo pharmacological effects in mice elicited by increasing doses of Cimbi-36 were assessed with the head-twitch response (HTR). The effective dose as extrapolated from both rat and pig data was low, 7.67 and 4.88 μSv/MBq, respectively. In addition, the estimated absorbed radiation dose to human target organs did not exceed safety levels. Administration of 0.5 mg/kg Cimbi-36 leads to significant HTR compared to saline, whereas 0.05 mg/kg Cimbi-36 (doses much larger than those given in conjunction with a PET scan) did not elicit a significant HTR. Administration of tracer doses of [11C]Cimbi-36 does not seem to be associated with unusual radiation burden or adverse clinical effects.

  17. Focused ultrasound-mediated noninvasive blood-brain barrier modulation: preclinical examination of efficacy and safety in various sonication parameters.

    PubMed

    Shin, Jaewoo; Kong, Chanho; Cho, Jae Sung; Lee, Jihyeon; Koh, Chin Su; Yoon, Min-Sik; Na, Young Cheol; Chang, Won Seok; Chang, Jin Woo

    2018-02-01

    OBJECTIVE The application of pharmacological therapeutics in neurological disorders is limited by the ability of these agents to penetrate the blood-brain barrier (BBB). Focused ultrasound (FUS) has recently gained attention for its potential application as a method for locally opening the BBB and thereby facilitating drug delivery into the brain parenchyma. However, this method still requires optimization to maximize its safety and efficacy for clinical use. In the present study, the authors examined several sonication parameters of FUS influencing BBB opening in small animals. METHODS Changes in BBB permeability were observed during transcranial sonication using low-intensity FUS in 20 adult male Sprague-Dawley rats. The authors examined the effects of FUS sonication with different sonication parameters, varying acoustic pressure, center frequency, burst duration, microbubble (MB) type, MB dose, pulse repetition frequency (PRF), and total exposure time. The focal region of BBB opening was identified by Evans blue dye. Additionally, H & E staining was used to identify blood vessel damage. RESULTS Acoustic pressure amplitude and burst duration were closely associated with enhancement of BBB opening efficiency, but these parameters were also highly correlated with tissue damage in the sonicated region. In contrast, MB types, MB dose, total exposure time, and PRF had an influence on BBB opening without conspicuous tissue damage after FUS sonication. CONCLUSIONS The study aimed to identify these influential conditions and provide safety and efficacy values for further studies. Future work based on the current results is anticipated to facilitate the implementation of FUS sonication for drug delivery in various CNS disease states in the near future.

  18. Good Laboratory Practice Preclinical Safety Studies for GSK2696273 (MLV Vector-Based Ex Vivo Gene Therapy for Adenosine Deaminase Deficiency Severe Combined Immunodeficiency) in NSG Mice.

    PubMed

    Carriglio, Nicola; Klapwijk, Jan; Hernandez, Raisa Jofra; Vezzoli, Michela; Chanut, Franck; Lowe, Rhiannon; Draghici, Elena; Nord, Melanie; Albertini, Paola; Cristofori, Patrizia; Richards, Jane; Staton, Hazel; Appleby, Jonathan; Aiuti, Alessandro; Sauer, Aisha V

    2017-03-01

    GSK2696273 (autologous CD34+ cells transduced with retroviral vector that encodes for the human adenosine deaminase [ADA] enzyme) is a gamma-retroviral ex vivo gene therapy of bone marrow-derived CD34+ cells for the treatment of adenosine deaminase deficiency severe combined immunodeficiency (ADA-SCID). ADA-SCID is a severe monogenic disease characterized by immunologic and nonimmunologic symptoms. Bone-marrow transplant from a matched related donor is the treatment of choice, but it is available for only a small proportion of patients. Ex vivo gene therapy of patient bone-marrow CD34+ cells is an alternative treatment. In order to prepare for a marketing authorization application in the European Union, preclinical safety studies in mice were requested by the European Medicines Agency (EMA). A pilot study and a main biodistribution study were performed according to Good Laboratory Practice (GLP) at the San Raffaele Telethon Institute for Gene Therapy test facility. In the main study, human umbilical cord blood (UCB)-derived CD34+ cells were transduced with gamma-retroviral vector used in the production of GSK2696273. Groups of 10 male and 10 female NOD-SCID gamma (NSG) mice were injected intravenously with a single dose of transduced- or mock-transduced UCB CD34+ cells, and they were observed for 4 months. Engraftment and multilineage differentiation of blood cells was observed in the majority of animals in both groups. There was no significant difference in the level of chimerism between the two groups. In the gene therapy group, vector was detectable in lymphohemopoietic and nonlymphohemopoietic tissues, consistent with the presence of gene-modified human hematopoietic donor cells. Given the absence of relevant safety concerns in the data, the nonclinical studies and the clinical experience with GSK2696273 supported a successful application for market authorization in the European Union for the treatment of ADA-SCID patients, for whom no suitable human leukocyte

  19. Preclinical safety profile of trastuzumab emtansine (T-DM1): Mechanism of action of its cytotoxic component retained with improved tolerability

    SciTech Connect

    Poon, Kirsten Achilles, E-mail: achilles.kirsten@gene.com; Flagella, Kelly; Beyer, Joseph

    2013-12-01

    Trastuzumab emtansine (T-DM1) is the first antibody-drug conjugate (ADC) approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. The therapeutic premise of ADCs is based on the hypothesis that targeted delivery of potent cytotoxic drugs to tumors will provide better tolerability and efficacy compared with non-targeted delivery, where poor tolerability can limit efficacious doses. Here, we present results from preclinical studies characterizing the toxicity profile of T-DM1, including limited assessment of unconjugated DM1. T-DM1 binds primate ErbB2 and human HER2 but not the rodent homolog c-neu. Therefore, antigen-dependent and non-antigen-dependent toxicity was evaluated in monkeysmore » and rats, respectively, in both single- and repeat-dose studies; toxicity of DM1 was assessed in rats only. T-DM1 was well tolerated at doses up to 40 mg/kg (∼ 4400 μg DM1/m{sup 2}) and 30 mg/kg (∼ 6000 μg DM1/m{sup 2}) in rats and monkeys, respectively. In contrast, DM1 was only tolerated up to 0.2 mg/kg (1600 μg DM1/m{sup 2}). This suggests that at least two-fold higher doses of the cytotoxic agent are tolerated in T-DM1, supporting the premise of ADCs to improve the therapeutic index. In addition, T-DM1 and DM1 safety profiles were similar and consistent with the mechanism of action of DM1 (i.e., microtubule disruption). Findings included hepatic, bone marrow/hematologic (primarily platelet), lymphoid organ, and neuronal toxicities, and increased numbers of cells of epithelial and phagocytic origin in metaphase arrest. These adverse effects did not worsen with chronic dosing in monkeys and are consistent with those reported in T-DM1-treated patients to date. - Highlights: • T-DM1 was well tolerated in preclinical studies in rats and cynomolgus monkeys. • T-DM1 is associated with bone marrow/hematologic, hepatic, and neuronal toxicities. • T-DM1 toxicities are related to DM1 mechanisms of action and

  20. Chronic preclinical safety evaluation of EPO-018B, a pegylated peptidic erythropoiesis-stimulating agent in monkeys and rats

    SciTech Connect

    Gong, Xue-Lian; Gu, Xiao-Lei

    EPO-018B, a synthetic peptide-based erythropoiesis stimulating agent (ESA), is mainly designed for treatment of anemia caused by chronic renal failure and chemotherapy against cancer. It overcomes the deficiencies of currently approved ESA, including the frequent administration of temperature-sensitive recombinant protein and anti-EPO antibody-mediated pure red cell aplasia (PRCA). This study was designed to evaluate the potential chronic toxicity of EPO-018B. Subcutaneous administration doses were designed as 0, 0.2, 1 and 10 mg/kg for six months for 160 rats (20/gender/group) and 0, 0.3, 3 and 20 mg/kg for nine months for 32 monkeys (4/gender/group) once every three weeks. The vehicles receivedmore » the same volume of physiological saline injection. All animals survived to the scheduled necropsies after six weeks (for rats) and fourteen weeks (for monkeys) recovery period, except for the two high-dose female rats and two high-dose male monkeys, which were considered related to the increased RBCs, chronic blood hyperviscosity and chronic cardiac injury. EPO-018B is supposed to be subcutaneously injected once every month and the intended human therapeutic dose is 0.025 mg/kg. The study findings at 0.2 mg/kg for rats and 0.3 mg/kg for monkeys were considered to be the study NOAEL (the no observed adverse effect level), which were more than ten times the intended human therapeutic dose. Higher doses caused adverse effects related to the liver toxicity, cardiotoxicity, appearance of neutralizing antibodies of EPO-018B and the decrease of serum glucose and cholesterol. Most treatment-induced effects were reversible or revealed ongoing recovery upon the discontinuation of treatment. The sequelae occurred in rats and monkeys were considered secondary to exaggerated pharmacology and would less likely occur in the intended patient population. As to the differences between human beings and animals, the safety of EPO-018B need to be further confirmed in the future

  1. Preclinical correction of human Fanconi anemia complementation group A bone marrow cells using a safety-modified lentiviral vector.

    PubMed

    Becker, P S; Taylor, J A; Trobridge, G D; Zhao, X; Beard, B C; Chien, S; Adair, J; Kohn, D B; Wagner, J E; Shimamura, A; Kiem, H-P

    2010-10-01

    One of the major hurdles for the development of gene therapy for Fanconi anemia (FA) is the increased sensitivity of FA stem cells to free radical-induced DNA damage during ex vivo culture and manipulation. To minimize this damage, we have developed a brief transduction procedure for lentivirus vector-mediated transduction of hematopoietic progenitor cells from patients with Fanconi anemia complementation group A (FANCA). The lentiviral vector FancA-sW contains the phosphoglycerate kinase promoter, the FANCA cDNA, and a synthetic, safety-modified woodchuck post transcriptional regulatory element (sW). Bone marrow mononuclear cells or purified CD34(+) cells from patients with FANCA were transduced in an overnight culture on recombinant fibronectin peptide CH-296, in low (5%) oxygen, with the reducing agent, N-acetyl-L-cysteine (NAC), and a combination of growth factors, granulocyte colony-stimulating factor (G-CSF), Flt3 ligand, stem cell factor, and thrombopoietin. Transduced cells plated in methylcellulose in hypoxia with NAC showed increased colony formation compared with 21% oxygen without NAC (P<0.03), showed increased resistance to mitomycin C compared with green fluorescent protein (GFP) vector-transduced controls (P<0.007), and increased survival. Thus, combining short transduction and reducing oxidative stress may enhance the viability and engraftment of gene-corrected cells in patients with FANCA.

  2. Evaluation of Marbofloxacin in Beagle Dogs After Oral Dosing: Preclinical Safety Evaluation and Comparative Pharmacokinetics of Two Different Tablets

    PubMed Central

    Lei, Zhixin; Liu, Qianying; Yang, Bing; Khaliq, Haseeb; Ahmed, Saeed; Fan, Bowen; Cao, Jiyue; He, Qigai

    2018-01-01

    The current study evaluates a tested marbofloxacin tablet (MBT) (Petsen), in terms of bioavailability and pharmacokinetics (PK) in a comparison of the commercialized and standard tablet (Marbocyl) in beagle dogs. Four different bacterial species were selected for the determination of the minimal inhibitory concentration (MIC) against marbofloxacin (MBF). Target animal safety studies were conducted with a wide spectrum of dosages of Petsen. Pharmacokinetics and bioavailability of Petsen were observed after the oral administration of a recommended dosage of 2 mg/kg. The MIC90 of MBF against Staphylococcus aureus, Escherichia coli, Pasteurella multocida, and Streptococcus were 2.00, 4.00, 0.25, and 0.50 μg/ml, respectively. These results showed that the MBT has an expected antimicrobial activity in vitro. The main parameters of t1/2β, Clb, AUC0−∞, Cmax, and Ke were 22.14 h, 0.15 L/h, 13.27 μg.h/ml, 0.95 μg/ml, 0.09 h−1, and 16.47 h, 0.14 L/h, 14.10 μg.h/ml, 0.97 μg/ml, 0.11 h−1 after the orally administrated Petsen and Marbocyl, while no biologically significant changes and toxicological significance have been found by their comparison. These findings indicate that the Petsen had a slow elimination, high bioavailability and kinetically similar to the commercialized Marbocyl. Furthermore, no statistically significant differences were distinguished on the continuous gradient dosages of 2, 6, and 10 mg/kg in the term of the clinical presentation. The present study results displayed that the tested MBT (Petsen) was safe, with limited toxicity, which was similar to the commercialized tablet (Marbocyl), could provide an alternative MBT as a veterinary medicine in beagle dogs. PMID:29692725

  3. A Preclinical Study of the Safety and Efficacy of Occlusin Trade-Mark-Sign 500 Artificial Embolization Device in Sheep

    SciTech Connect

    Owen, Richard J., E-mail: drrichardowen@tbwifi.ca; Nation, Patrick N.; Polakowski, Robert

    Introduction: This study evaluated the safety, effectiveness, and biodegradation of a new embolic agent, Occlusin Trade-Mark-Sign 503 Artificial Embolization Device (OCL 503). The agent consists of biodegradable poly-lactic-co-glycolic acid microspheres (150-212 {mu}m) coated with type I bovine collagen and was compared with Embosphere{sup Registered-Sign} Microspheres (300-500 {mu}m) in this controlled study of uterine artery embolization (UAE) in sheep. Methods: Unilateral UAE was performed in 32 adult ewes randomly assigned. Vessels were embolized to effective stasis. The cohort was divided into four groups, which were sacrificed at 1, 3, 6, and 12 months. Results: Both agents were 100% effective in achievingmore » stasis. At 6 months, all OCL 503-treated arteries were occluded, the microspheres degraded with time, and at 12 months all four animals examined demonstrated recanalization. OCL 503 was found in the untreated uterine artery in one animal with no other evidence of non target embolization. In the Embosphere-treated group, all vessels remained occluded and microspheres were detected in the contralateral uterine artery in 6 of 15 examined vessels and in 10 vaginal, 2 ovarian, and 1 vesical artery. No procedural-related complications were seen in either group. Conclusions: OCL 503 is as effective an embolic agent as Embosphere{sup Registered-Sign} Microspheres when embolizing ovine uterine arteries and resorbs with time, allowing recanalization of the treated arteries. No device-related issues or adverse events were observed.« less

  4. Preclinical profile of cabazitaxel

    PubMed Central

    Vrignaud, Patricia; Semiond, Dorothée; Benning, Veronique; Beys, Eric; Bouchard, Hervé; Gupta, Sunil

    2014-01-01

    First-generation taxanes have changed the treatment paradigm for a wide variety of cancers, but innate or acquired resistance frequently limits their use. Cabazitaxel is a novel second-generation taxane developed to overcome such resistance. In vitro, cabazitaxel showed similar antiproliferative activity to docetaxel in taxane-sensitive cell lines and markedly greater activity in cell lines resistant to taxanes. In vivo, cabazitaxel demonstrated excellent antitumor activity in a broad spectrum of docetaxel-sensitive tumor xenografts, including a castration-resistant prostate tumor xenograft, HID28, where cabazitaxel exhibited greater efficacy than docetaxel. Importantly, cabazitaxel was also active against tumors with innate or acquired resistance to docetaxel, suggesting therapeutic potential for patients progressing following taxane treatment and those with docetaxel-refractory tumors. In patients with tumors of the central nervous system (CNS), and in patients with pediatric tumors, therapeutic success with first-generation taxanes has been limited. Cabazitaxel demonstrated greater antitumor activity than docetaxel in xenograft models of CNS disease and pediatric tumors, suggesting potential clinical utility in these special patient populations. Based on therapeutic synergism observed in an in vivo tumor model, cabazitaxel is also being investigated clinically in combination with cisplatin. Nonclinical evaluation of the safety of cabazitaxel in a range of animal species showed largely reversible changes in the bone marrow, lymphoid system, gastrointestinal tract, and male reproductive system. Preclinical safety signals of cabazitaxel were consistent with the previously reported safety profiles of paclitaxel and docetaxel. Clinical observations with cabazitaxel were consistent with preclinical results, and cabazitaxel is indicated, in combination with prednisone, for the treatment of patients with hormone-refractory metastatic prostate cancer previously treated

  5. Discovery and safety profiling of a potent preclinical candidate, (4-[4-[[(3R)-3-(hydroxycarbamoyl)-8-azaspiro[4.5]decan-3-yl]sulfonyl]phenoxy]-N-methylbenzamide) (CM-352), for the prevention and treatment of hemorrhage.

    PubMed

    Orbe, Josune; Rodríguez, José A; Sánchez-Arias, Juan A; Salicio, Agustina; Belzunce, Miriam; Ugarte, Ana; Chang, Haisul C Y; Rabal, Obdulia; Oyarzabal, Julen; Páramo, José A

    2015-04-09

    Discovery of potent and safe therapeutics that improve upon currently available antifibrinolytics, e.g., tranexamic acid (TXA, 1) and aprotinin, has been challenging. Matrix metalloproteinases (MMPs) participate in thrombus dissolution. Then we designed a novel series of optimized MMP inhibitors that went through phenotypic screening consisting of thromboelastometry and mouse tail bleeding. Our optimized lead compound, CM-352 (2), inhibited fibrinolysis in human whole blood functional assays and was more effective than the current standard of care, 1, in the tail-bleeding model using a 30 000 times lower dose. Moreover, 2 reduced blood loss during liver hepatectomy, while 1 and aprotinin had no effect. Molecule 2 displayed optimal pharmacokinetic and safety profiles with no evidence of thrombosis or coagulation impairment. This novel mechanism of action, targeting MMP, defines a new class of antihemorrhagic agents without interfering with normal hemostatic function. Furthermore, 2 represents a preclinical candidate for the acute treatment of bleeding.

  6. Immunohistochemical analysis of S6K1 and S6K2 localization in human breast tumors.

    PubMed

    Filonenko, Valeriy V; Tytarenko, Ruslana; Azatjan, Sergey K; Savinska, Lilya O; Gaydar, Yuriy A; Gout, Ivan T; Usenko, Vasiliy S; Lyzogubov, Valeriy V

    2004-12-01

    To perform an immunohistochemical analysis of human breast adenomas and adenocarcinomas as well as normal breast tissues in respect of S6 ribosomal protein kinase (S6K) expression and localization in normal and transformed cells. The expression level and localization of S6K have been detected in formalin fixed, paraffin embedded sections of normal human breast tissues, adenomas and adenocarcinomas with different grade of differentiation. Immunohistochemical detection of S6K1 and S6K2 in normal human breast tissues and breast tumors were performed using specific monoclonal and polyclonal antibodies against S6K1 and S6K2 with following semiquantitative analysis. The increase of S6K content in the cytoplasm of epithelial cells in benign and malignant tumors has been detected. Nuclear accumulation of S6K1 and to a greater extend S6K2 have been found in breast adenocarcinomas. About 80% of breast adenocarcinomas cases revealed S6K2 nuclear staining comparing to normal tissues. In 31% of cases more then 50% of cancer cells had strong nuclear staining. Accumulation of S6K1 in the nucleus of neoplastic cells has been demonstrated in 25% of cases. Nuclear localization of S6K in the epithelial cells in normal breast tissues has not been detected. Immunohistochemical analysis of S6K1 and S6K2 expression in normal human breast tissues, benign and malignant breast tumors clearly indicates that both kinases are overexpressed in breast tumors. Semiquantitative analysis of peculiarities of S6K localization in normal tissues and tumors revealed that nucleoplasmic accumulation of S6K (especially S6K2) is a distinguishing feature of cancer cells.

  7. Preclinical restorative training.

    PubMed

    Ferguson, Michael B; Sobel, Morton; Niederman, Richard

    2002-10-01

    In conjunction with its problem-based learning curriculum, Harvard School of Dental Medicine (HSDM) developed a shortened preclinical restorative training curriculum. This study compared our curriculum with those in other dental schools and examined student reaction to it. Twenty-nine U.S. dental schools responded to a survey regarding the length of their preclinical course in Operative Dentistry. Nationally, preclinical courses ranged from 179 hours to 280 hours (mean +/- SEM = 193 +/- 9 hours; n = 29). In marked contrast, the new seventy-five-hour preclinical curriculum at Harvard was the lowest of any school, and significantly lower than the U.S. average (p < 0.01). In Harvard's previous curriculum, students spent 232 curriculum hours. Reactions of Harvard students to this compact preclinical curriculum were surveyed using a three-topic, three-category survey instrument. Results indicated that, prior to beginning clinical patient care, approximately 80 percent of students felt that the course was too short and 20 percent just right. Conversely, and retrospectively, after completing their dental school training, only 35 percent felt it was too short, and 65 percent felt it was just right. Retrospectively, in terms of clinical preparedness, 55 percent felt adequately prepared and 35 percent felt well prepared to treat their patients. No significant change was noted between Part II National Board scores following the change to the reduced curricula time. The average National Board Part II scores prior to initiating the new curriculum was 86.3, and afterwards, it was 86.2. Further, for the North East Regional Board, HSDM students in the past four years demonstrated a 98 percent overall success rate with 100 percent primary pass in the operative dentistry part of the examination. These results suggest that an abbreviated preclinical training is not only possible, but may make time available for training opportunities in other areas, such as aesthetic dental

  8. Single-cell Pharmacodynamic Monitoring of S6 Ribosomal Protein Phosphorylation in AML Blasts During a Clinical Trial Combining the mTOR Inhibitor Sirolimus and Intensive Chemotherapy

    PubMed Central

    Perl, Alexander E.; Kasner, Margaret T.; Shank, Doris; Luger, Selina M.; Carroll, Martin

    2011-01-01

    Purpose Integration of signal transduction inhibitors into chemotherapy regimens generally has generally not led to anticipated increases in response and survival. However, it remains unclear whether this is because of inadequate or inconsistent inhibition of target or other complex biology. The mammalian target of rapamycin (mTOR) signaling pathway is frequently activated in acute myelogenous leukemia (AML) and we previously demonstrated the safety of combining the mTOR inhibitor, sirolimus, with mitoxantrone, etoposide, and cytarabine (MEC) chemotherapy. However, we did not reliably determine the extent of mTOR inhibition on that study. Here we sought to develop an assay that allowed us to serially quantify mTOR kinase’s activation state during therapy. Experimental design To provide evidence of mTOR kinase activation and inhibition, we applied a validated whole blood fixation/permeabilization technique for flow cytometry in order to serially monitor S6 ribosomal protein (S6) phosphorylation in immunophenotypically-identified AML blasts. Results With this approach, we demonstrate activation of mTOR signaling in 8/10 subjects’ samples (80%) and conclusively show inhibition of mTOR in the majority of subjects’ tumor cell during therapy. Of note, S6 phosphorylation in AML blasts is heterogeneous and, in some cases, intrinsically resistant to rapamycin at clinically achieved concentrations. Conclusions The methodology described is rapid and reproducible. We demonstrate the feasibility of real-time, direct pharmacodynamic monitoring by flow cytometry during clinical trials combining intensive chemotherapy and signal transduction inhibitors. This approach greatly clarifies pharmacokinetic/pharmacodynamic relationships and has broad application to pre-clinical and clinical testing of drugs whose direct or downstream effects disrupt PI3K/AKT/mTOR signaling. PMID:22167413

  9. Phosphorylation of ribosomal protein S6 mediates compensatory renal hypertrophy

    PubMed Central

    Xu, Jinxian; Chen, Jianchun; Dong, Zheng; Meyuhas, Oded; Chen, Jian-Kang

    2014-01-01

    The molecular mechanism underlying renal hypertrophy and progressive nephron damage remains poorly understood. Here we generated congenic ribosomal protein S6 (rpS6) knockin mice expressing non-phosphorylatable rpS6 and found that uninephrectomy-induced renal hypertrophy was significantly blunted in these knockin mice. Uninephrectomy-induced increases in cyclin D1 and decreases in cyclin E in the remaining kidney were attenuated in the knockin mice compared to their wild-type littermates. Uninephrectomy induced rpS6 phosphorylation in the wild type mice; however, no rpS6 phosphorylation was detected in uninephrectomized or sham-operated knockin mice. Nonetheless, uninephrectomy stimulated comparable 4E-BP1 phosphorylation in both knockin and wild type mice, indicating that mTORC1 was still activated in the knockin mice. Moreover, the mTORC1 inhibitor rapamycin prevented both rpS6 and 4E-BP1 phosphorylation, significantly blunted uninephrectomy-induced renal hypertrophy in wild type mice, but did not prevent residual renal hypertrophy despite inhibiting 4E-BP1 phosphorylation in uninephrectomized knockin mice. Thus, both genetic and pharmacological approaches unequivocally demonstrate that phosphorylated rpS6 is a downstream effector of the mTORC1-S6K1 signaling pathway mediating renal hypertrophy. Hence, rpS6 phosphorylation facilitates the increase in cyclin D1 and decrease in cyclin E1 that underlie the hypertrophic nature of uninephrectomy-induced kidney growth. PMID:25229342

  10. Ferulic acid attenuates focal cerebral ischemia-induced decreases in p70S6 kinase and S6 phosphorylation.

    PubMed

    Koh, Phil-Ok

    2013-10-25

    Ferulic acid exhibits neuroprotective effects against focal cerebral ischemia. PI3/K and Akt signaling pathways play an essential role in protecting against cerebral ischemia. Mammalian target of rapamycin (mTOR), a major downstream target of Akt, regulates p70S6 kinase and S6, both of which are involved in ribosomal biogenesis and protein synthesis. I investigated whether ferulic acid regulates mTOR, p70S6 kinase, and S6 phosphorylation during brain ischemic injury. Rats were treated immediately with vehicle or ferulic acid (100mg/kg, i.v.) after middle cerebral artery occlusion (MCAO). Brains tissues were removed at 24h after the onset of MCAO and the cerebral cortex regions were collected. Ferulic acid reduced the MCAO-induced infarct volume. I showed previously that ferulic acid prevents the MCAO injury-induced decrease of Akt phosphorylation. In this study, MCAO injury induced decreases in mTOR, p70S6 kinase, and S6 phosphorylation levels, while ferulic acid attenuated the injury-induced decreases. Immunohistochemical staining demonstrated that ferulic acid prevented the MCAO-induced reduction in the number of positive cells for phosphorylated p70S6 kinase and phosphorylated S6. These findings suggest that ferulic acid has a neuroprotective function against focal cerebral ischemia by modulating p70S6 kinase expression and S6 phosphorylation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  11. Cholecystokinin (CCK) stimulates S6 phosphorylation and induced activation of S6 protein kinase in rat pancreatic acini

    SciTech Connect

    Sung, C.; Okabayashi, Y.; Williams, J.

    CCK and insulin stimulate pancreatic protein synthesis at a post transcriptional step. To better understand this regulation the authors evaluated the phosphorylation state of ribosomal protein S6 and the presence of a specific S6 protein kinase in pancreatic acini from diabetic rats. Both CCK and insulin increased S6 phosphorylation by up to 400% in intact TSP-labelled acini. The phorbol ester 12-0-tetradecanoylphorbol 13-acetate also stimulated both protein synthesis and S6 phosphorlyation suggesting a role for protein kinase C in mediating the effect of CCK. By contrast, the CaS ionophore ionomycin had no effect on either parameter. Recently, insulin has been shownmore » to activate a unique S6 kinase in various cells. To test for its presence, cytosolic extracts were prepared from acini stimulated with CCK and insulin by homogenization in US -glycerophosphate buffer and assayed for the kinase using el-TSP ATP and rat pancreatic ribosomes followed by SDS-polyacrylamide gel electrophoresis. CCK and insulin both increased S6 kinase activity which required neither CaS or phospholipid. The dose response for CCk was similar to S6 phosphorlyation in the intact acini. TPA did not stimulate the S6 kinase. Thus, CCK may induce S6 phosphorylation both via C kinase and by activation of a unique S6 kinase.« less

  12. Preclinical good laboratory practice-compliant safety study to evaluate biodistribution and tumorigenicity of a cartilage advanced therapy medicinal product (ATMP).

    PubMed

    Zscharnack, Matthias; Krause, Christoph; Aust, Gabriela; Thümmler, Christian; Peinemann, Frank; Keller, Thomas; Smink, Jeske J; Holland, Heidrun; Somerson, Jeremy S; Knauer, Jens; Schulz, Ronny M; Lehmann, Jörg

    2015-05-20

    The clinical development of advanced therapy medicinal products (ATMPs), a new class of drugs, requires initial safety studies that deviate from standard non-clinical safety protocols. The study provides a strategy to address the safety aspects of biodistribution and tumorigenicity of ATMPs under good laboratory practice (GLP) conditions avoiding cell product manipulation. Moreover, the strategy was applied on a human ATMP for cartilage repair. The testing strategy addresses biodistribution and tumorigenicity using a multi-step analysis without any cell manipulation to exclude changes of test item characteristics. As a safeguard measurement for meeting regulatory expectations, the project design and goals were discussed continuously with the regulatory authority using a staggered scientific advice concept. Subsequently, the strategy was applied to co.don chondrosphere® (huChon spheroid), a tissue-engineered matrix-free ATMP of human normal chondrocytes. In both the biodistribution and tumorigenicity studies, huChon spheroids were implanted subcutaneously into 40 immunodeficient mice. Biodistribution was studied 1 month after implantation. A skin disc containing the huChon spheroid, two surrounding skin rings and selected organs were analyzed by validated, gender-specific, highly-sensitive triplex qPCR and by immunohistochemistry (IHC). No human DNA was detected in distant skin rings and analyzed organs. IHC revealed no direct or indirect indications of cell migration. Tumorigenicity was assessed 6 months after huChon spheroid implantation by palpation, macroscopic inspection, histology and IHC. No mice from the huChon spheroid group developed a tumor at the implantation site. In two mice, benign tumors were detected that were negative for HLA-ABC, suggesting that they were of spontaneous murine origin. In summary, the presented strategy using a multi-step analysis was confirmed to be suitable for safety studies of ATMPs.

  13. Preclinical Evaluation of Efficacy and Safety of an Improved Lentiviral Vector for the Treatment of β-Thalassemia and Sickle Cell Disease

    PubMed Central

    Negre, Olivier; Bartholomae, Cynthia; Beuzard, Yves; Cavazzana, Marina; Christiansen, Lauryn; Courne, Céline; Deichmann, Annette; Denaro, Maria; de Dreuzy, Edouard; Finer, Mitchell; Fronza, Raffaele; Gillet-Legrand, Béatrix; Joubert, Christophe; Kutner, Robert; Leboulch, Philippe; Maouche, Leïla; Paulard, Anaïs; Pierciey, Francis J.; Rothe, Michael; Ryu, Byoung; Schmidt, Manfred; von Kalle, Christof; Payen, Emmanuel; Veres, Gabor

    2015-01-01

    A previously published clinical trial demonstrated the benefit of autologous CD34+ cells transduced with a self-inactivating lentiviral vector (HPV569) containing an engineered β-globin gene (βA-T87Q-globin) in a subject with β-thalassemia major. This vector has been modified to increase transduction efficacy without compromising safety. In vitro analyses indicated that the changes resulted in both increased vector titers (3 to 4 fold) and increased transduction efficacy (2 to 3 fold). An in vivo study in which 58 β-thalassemic mice were transplanted with vector- or mock-transduced syngenic bone marrow cells indicated sustained therapeutic efficacy. Secondary transplantations involving 108 recipients were performed to evaluate long-term safety. The six month study showed no hematological or biochemical toxicity. Integration site (IS) profile revealed an oligo/polyclonal hematopoietic reconstitution in the primary transplants and reduced clonality in secondary transplants. Tumor cells were detected in the secondary transplant mice in all treatment groups (including the control group), without statistical differences in the tumor incidence. Immunohistochemistry and quantitative PCR demonstrated that tumor cells were not derived from transduced donor cells. This comprehensive efficacy and safety data provided the basis for initiating two clinical trials with this second generation vector (BB305) in Europe and in the USA in patients with β-thalassemia major and sickle cell disease. PMID:25429463

  14. Non-clinical and Pre-clinical Testing to Demonstrate Safety of the Barostim Neo Electrode for Activation of Carotid Baroreceptors in Chronic Human Implants

    PubMed Central

    Wilks, Seth J.; Hara, Seth A.; Ross, Erika K.; Nicolai, Evan N.; Pignato, Paul A.; Cates, Adam W.; Ludwig, Kip A.

    2017-01-01

    The Barostim neo™ electrode was developed by CVRx, Inc.to deliver baroreflex activation therapy (BAT)™ to treat hypertension and heart failure. The neo electrode concept was designed to deliver electrical stimulation to the baroreceptors within the carotid sinus bulb, while minimizing invasiveness of the implant procedure. This device is currently CE marked in Europe, and in a Pivotal (akin to Phase III) Trial in the United States. Here we present the in vitro and in vivo safety testing that was completed in order to obtain necessary regulatory approval prior to conducting human studies in Europe, as well as an FDA Investigational Device Exemption (IDE) to conduct a Pivotal Trial in the United States. Stimulated electrodes (10 mA, 500 μs, 100 Hz) were compared to unstimulated electrodes using optical microscopy and several electrochemical techniques over the course of 27 weeks. Electrode dissolution was evaluated by analyzing trace metal content of solutions in which electrodes were stimulated. Lastly, safety testing under Good Laboratory Practice guidelines was conducted in an ovine animal model over a 12 and 24 week time period, with results processed and evaluated by an independent histopathologist. Long-term stimulation testing indicated that the neo electrode with a sputtered iridium oxide coating can be stimulated at maximal levels for the lifetime of the implant without clinically significant dissolution of platinum or iridium, and without increasing the potential at the electrode interface to cause hydrolysis or significant tissue damage. Histological examination of tissue that was adjacent to the neo electrodes indicated no clinically significant signs of increased inflammation and no arterial stenosis as a result of 6 months of continuous stimulation. The work presented here involved rigorous characterization and evaluation testing of the neo electrode, which was used to support its safety for chronic implantation. The testing strategies discussed

  15. Ribosomal protein S6 kinase 1 signaling regulates mammalian lifespan

    PubMed Central

    Selman, Colin; Tullet, Jennifer M.A.; Wieser, Daniela; Irvine, Elaine; Lingard, Steven J.; Choudhury, Agharul I.; Claret, Marc; Al-Qassab, Hind; Carmignac, Danielle; Ramadani, Faruk; Woods, Angela; Robinson, Iain C.A.; Schuster, Eugene; Batterham, Rachel L.; Kozma, Sara C.; Thomas, George; Carling, David; Okkenhaug, Klaus; Thornton, Janet M.; Partridge, Linda; Gems, David; Withers, Dominic J.

    2016-01-01

    Caloric restriction (CR) protects against aging and disease but the mechanisms by which this affects mammalian lifespan are unclear. We show in mice that deletion of the nutrient-responsive mTOR (mammalian target of rapamycin) signaling pathway component ribosomal S6 protein kinase 1 (S6K1) led to increased lifespan and resistance to age-related pathologies such as bone, immune and motor dysfunction and loss of insulin sensitivity. Deletion of S6K1 induced gene expression patterns similar to those seen in CR or with pharmacological activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK), a conserved regulator of the metabolic response to CR. Our results demonstrate that S6K1 influences healthy mammalian lifespan, and suggest therapeutic manipulation of S6K1 and AMPK might mimic CR and provide broad protection against diseases of aging. PMID:19797661

  16. Inhibition of mammalian S6 kinase by resveratrol suppresses autophagy

    PubMed Central

    Armour, Sean M.; Baur, Joseph A.; Hsieh, Sherry N.; Land-Bracha, Abigail; Thomas, Sheila M.; Sinclair, David A.

    2009-01-01

    Resveratrol is a plant-derived polyphenol that promotes health and disease resistance in rodent models, and extends lifespan in lower organisms. A major challenge is to understand the biological processes and molecular pathways by which resveratrol induces these beneficial effects. Autophagy is a critical process by which cells turn over damaged components and maintain bioenergetic requirements. Disruption of the normal balance between pro- and anti-autophagic signals is linked to cancer, liver disease, and neurodegenerative disorders. Here we show that resveratrol attenuates autophagy in response to nutrient limitation or rapamycin in multiple cell lines through a pathway independent of a known target, SIRT1. In a large-scalein vitro kinase screen we identified p70 S6 kinase (S6K1) as a target of resveratrol. Blocking S6K1 activity by expression of a dominant-negative mutant or RNA interference is sufficient to disrupt autophagy to a similar extent as resveratrol. Furthermore, co-administration of resveratrol with S6K1 knockdown does not produce an additive effect. These data indicate that S6K1 is important for the full induction of autophagy in mammals and raise the possibility that some of the beneficial effects of resveratrol are due to modulation of S6K1 activity. PMID:20157535

  17. Inhibition of mammalian S6 kinase by resveratrol suppresses autophagy.

    PubMed

    Armour, Sean M; Baur, Joseph A; Hsieh, Sherry N; Land-Bracha, Abigail; Thomas, Sheila M; Sinclair, David A

    2009-06-03

    Resveratrol is a plant-derived polyphenol that promotes health and disease resistance in rodent models, and extends lifespan in lower organisms. A major challenge is to understand the biological processes and molecular pathways by which resveratrol induces these beneficial effects. Autophagy is a critical process by which cells turn over damaged components and maintain bioenergetic requirements. Disruption of the normal balance between pro- and anti-autophagic signals is linked to cancer, liver disease, and neurodegenerative disorders. Here we show that resveratrol attenuates autophagy in response to nutrient limitation or rapamycin in multiple cell lines through a pathway independent of a known target, SIRT1. In a large-scalein vitro kinase screen we identified p70 S6 kinase (S6K1) as a target of resveratrol. Blocking S6K1 activity by expression of a dominant-negative mutant or RNA interference is sufficient to disrupt autophagy to a similar extent as resveratrol. Furthermore, co-administration of resveratrol with S6K1 knockdown does not produce an additive effect. These data indicate that S6K1 is important for the full induction of autophagy in mammals and raise the possibility that some of the beneficial effects of resveratrol are due to modulation of S6K1 activity.

  18. Employing a gain-of-function factor IX variant R338L to advance the efficacy and safety of hemophilia B human gene therapy: preclinical evaluation supporting an ongoing adeno-associated virus clinical trial.

    PubMed

    Monahan, Paul E; Sun, Junjiang; Gui, Tong; Hu, Genlin; Hannah, William B; Wichlan, David G; Wu, Zhijian; Grieger, Joshua C; Li, Chengwen; Suwanmanee, Thipparat; Stafford, Darrel W; Booth, Carmen J; Samulski, Jade J; Kafri, Tal; McPhee, Scott W J; Samulski, R Jude

    2015-02-01

    , 100-500%). These preclinical studies demonstrate a safety:efficacy profile supporting an ongoing phase 1/2 human clinical trial of the scAAV8.FIXR338L vector (designated BAX335).

  19. Faraday effect in Sn2P2S6 crystals.

    PubMed

    Krupych, Oleh; Adamenko, Dmytro; Mys, Oksana; Grabar, Aleksandr; Vlokh, Rostyslav

    2008-11-10

    We have revealed a large Faraday rotation in tin thiohypodiphosphate (Sn(2)P(2)S(6)) crystals, which makes this material promising for magneto-optics. The effective Faraday tensor component and the Verdet constant for the direction of the optic axis have been determined by measuring the pure Faraday rotation in Sn(2)P(2)S(6) crystals with both the single-ray and small-angular polarimetric methods at the normal conditions and a wavelength of 632.8 nm. The effective Verdet constant is found to be equal to 115 rad/T x m.

  20. Mutagenic and cytotoxic properties of 6-thioguanine, S6-methylthioguanine, and guanine-S6-sulfonic acid.

    PubMed

    Yuan, Bifeng; Wang, Yinsheng

    2008-08-29

    Thiopurine drugs, including 6-thioguanine ((S)G), 6-mercaptopurine, and azathioprine, are widely employed anticancer agents and immunosuppressants. The formation of (S)G nucleotides from the thiopurine prodrugs and their subsequent incorporation into nucleic acids are important for the drugs to exert their cytotoxic effects. (S)G in DNA can be methylated by S-adenosyl-l-methionine to give S(6)-methylthioguanine (S(6)mG) and oxidized by UVA light to render guanine-S(6)-sulfonic acid ((SO3H)G). Here, we constructed single-stranded M13 shuttle vectors carrying a (S)G, S(6)mG, or (SO3H)G at a unique site and allowed the vectors to propagate in wild-type and bypass polymerase-deficient Escherichia coli cells. Analysis of the replication products by using the competitive replication and adduct bypass and a slightly modified restriction enzyme digestion and post-labeling assays revealed that, although none of the three thionucleosides considerably blocked DNA replication in all transfected E. coli cells, both S(6)mG and (SO3H)G were highly mutagenic, which resulted in G-->A mutation at frequencies of 94 and 77%, respectively, in wild-type E. coli cells. Deficiency in bypass polymerases does not result in alteration of mutation frequencies of these two lesions. In contrast to what was found from previous steady-state kinetic analysis, our data demonstrated that 6-thioguanine is mutagenic, with G-->A transition occurring at a frequency of approximately 10%. The mutagenic properties of 6-thioguanine and its derivatives revealed in the present study offered important knowledge about the biological implications of these thionucleosides.

  1. Palmatine inhibits growth and invasion in prostate cancer cell: Potential role for rpS6/NFκB/FLIP.

    PubMed

    Hambright, Heather G; Batth, Izhar Singh; Xie, Jianping; Ghosh, Rita; Kumar, Addanki Pratap

    2015-10-01

    Novel agents are desperately needed for improving the quality of life and 5-year survival to more than 30% for metastatic castrate-resistant prostate cancer. Previously we showed that Nexrutine, Phellodendron amurense bark extract, inhibits prostate tumor growth in vitro and in vivo. Subsequently using biochemical fractionation we identified butanol fraction contributes to the observed biological activities. We report here that palmatine, which is present in the butanol fraction, selectively inhibits growth of prostate cancer cells without significant effect on non-tumorigenic prostate epithelial cells. By screening receptor tyrosine kinases in a protein kinase array, we identified ribosomal protein S6, a downstream target of p70S6K and the Akt/mTOR signaling cascade as a potential target. We further show that palmatine treatment is associated with decreased activation of NFκB and its downstream target gene FLIP. These events led to inhibition of invasion. Similar results were obtained using parent extract Nexrutine (Nx) suggesting that palmatine either in the purified form or as one of the components in Nx is a potent cytotoxic agent with tumor invasion inhibitory properties. Synergistic inhibition of rpS6/NFκB/FLIP axis with palmatine may have therapeutic potential for the treatment of prostate cancer and possibly other malignancies with their constitutive activation. These data support a biological link between rpS6/NFκB/FLIP in mediating palmatine-induced inhibitory effects and warrants additional preclinical studies to test its therapeutic efficacy. © 2014 Wiley Periodicals, Inc.

  2. AdS6 solutions of type II supergravity

    NASA Astrophysics Data System (ADS)

    Apruzzi, Fabio; Fazzi, Marco; Passias, Achilleas; Rosa, Dario; Tomasiello, Alessandro

    2014-11-01

    Very few AdS6 × M 4 supersymmetric solutions are known: one in massive IIA, and two IIB solutions dual to it. The IIA solution is known to be unique; in this paper, we use the pure spinor approach to give a classification for IIB supergravity. We reduce the problem to two PDEs on a two-dimensional space Σ. M 4 is then a fibration of S 2 over Σ; the metric and fluxes are completely determined in terms of the solution to the PDEs. The results seem likely to accommodate near-horizon limits of ( p, q)-fivebrane webs studied in the literature as a source of CFT5's. We also show that there are no AdS6 solutions in eleven-dimensional supergravity.

  3. Study partners should be required in preclinical Alzheimer's disease trials.

    PubMed

    Grill, Joshua D; Karlawish, Jason

    2017-12-06

    In an effort to intervene earlier in Alzheimer's disease (AD), clinical trials are testing promising candidate therapies in preclinical disease. Preclinical AD trial participants are cognitively normal, functionally independent, and autonomous decision-makers. Yet, like AD dementia trials, preclinical trials require dual enrollment of a participant and a knowledgeable informant, or study partner. The requirement of dyadic enrollment is a barrier to recruitment and may present unique ethical challenges. Despite these limitations, the requirement should continue. Study partners may be essential to ensure participant safety and wellbeing, including overcoming distress related to biomarker disclosure and minimizing risk for catastrophic reactions and suicide. The requirement may maximize participant retention and ensure data integrity, including that study partners are the source of data that will ultimately instruct whether a new treatment has a clinical benefit and meaningful impact on the population health burden associated with AD. Finally, study partners are needed to ensure the scientific and clinical value of trials. Preclinical AD will represent a new model of care, in which persons with no symptoms are informed of probable cognitive decline and eventual dementia. The rationale for early diagnosis in symptomatic AD is equally applicable in preclinical AD-to minimize risk, maximize quality of life, and ensure optimal planning and communication. Family members and other sources of support will likely be essential to the goals of this new model of care for preclinical AD patients and trials must instruct this clinical practice.

  4. Preclinical drug development.

    PubMed

    Brodniewicz, Teresa; Grynkiewicz, Grzegorz

    2010-01-01

    Life sciences provide reasonably sound prognosis for a number and nature of therapeutic targets on which drug design could be based, and search for new chemical entities--future new drugs, is now more than ever based on scientific principles. Nevertheless, current very long and incredibly costly drug discovery and development process is very inefficient, with attrition rate spanning from many thousands of new chemical structures, through a handful of validated drug leads, to single successful new drug launches, achieved in average after 13 years, with compounded cost estimates from hundreds of thousands to over one billion US dollars. Since radical pharmaceutical innovation is critically needed, number of new research projects concerning this area is steeply rising outside of big pharma industry--both in academic environment and in small private companies. Their prospective success will critically depend on project management, which requires combined knowledge of scientific, technical and legal matters, comprising regulations concerning admission of new drug candidates to be subjects of clinical studies. This paper attempts to explain basic rules and requirements of drug development within preclinical study period, in case of new chemical entities of natural or synthetic origin, which belong to low molecular weight category.

  5. NCI Pediatric Preclinical Testing Consortium

    Cancer.gov

    NCI has awarded grants to five research teams to participate in its Pediatric Preclinical Testing Consortium, which is intended to help to prioritize which agents to pursue in pediatric clinical trials.

  6. Synaptic Activation of Ribosomal Protein S6 Phosphorylation Occurs Locally in Activated Dendritic Domains

    ERIC Educational Resources Information Center

    Pirbhoy, Patricia Salgado; Farris, Shannon; Steward, Oswald

    2016-01-01

    Previous studies have shown that induction of long-term potentiation (LTP) induces phosphorylation of ribosomal protein S6 (rpS6) in postsynaptic neurons, but the functional significance of rpS6 phosphorylation is poorly understood. Here, we show that synaptic stimulation that induces perforant path LTP triggers phosphorylation of rpS6 (p-rpS6)…

  7. The basics of preclinical drug development for neurodegenerative disease indications.

    PubMed

    Steinmetz, Karen L; Spack, Edward G

    2009-06-12

    Preclinical development encompasses the activities that link drug discovery in the laboratory to initiation of human clinical trials. Preclinical studies can be designed to identify a lead candidate from several hits; develop the best procedure for new drug scale-up; select the best formulation; determine the route, frequency, and duration of exposure; and ultimately support the intended clinical trial design. The details of each preclinical development package can vary, but all have some common features. Rodent and nonrodent mammalian models are used to delineate the pharmacokinetic profile and general safety, as well as to identify toxicity patterns. One or more species may be used to determine the drug's mean residence time in the body, which depends on inherent absorption, distribution, metabolism, and excretion properties. For drugs intended to treat Alzheimer's disease or other brain-targeted diseases, the ability of a drug to cross the blood brain barrier may be a key issue. Toxicology and safety studies identify potential target organs for adverse effects and define the Therapeutic Index to set the initial starting doses in clinical trials. Pivotal preclinical safety studies generally require regulatory oversight as defined by US Food and Drug Administration (FDA) Good Laboratory Practices and international guidelines, including the International Conference on Harmonization. Concurrent preclinical development activities include developing the Clinical Plan and preparing the new drug product, including the associated documentation to meet stringent FDA Good Manufacturing Practices regulatory guidelines. A wide range of commercial and government contract options are available for investigators seeking to advance their candidate(s). Government programs such as the Small Business Innovative Research and Small Business Technology Transfer grants and the National Institutes of Health Rapid Access to Interventional Development Pilot Program provide funding and

  8. The basics of preclinical drug development for neurodegenerative disease indications

    PubMed Central

    Steinmetz, Karen L; Spack, Edward G

    2009-01-01

    Preclinical development encompasses the activities that link drug discovery in the laboratory to initiation of human clinical trials. Preclinical studies can be designed to identify a lead candidate from several hits; develop the best procedure for new drug scale-up; select the best formulation; determine the route, frequency, and duration of exposure; and ultimately support the intended clinical trial design. The details of each preclinical development package can vary, but all have some common features. Rodent and nonrodent mammalian models are used to delineate the pharmacokinetic profile and general safety, as well as to identify toxicity patterns. One or more species may be used to determine the drug's mean residence time in the body, which depends on inherent absorption, distribution, metabolism, and excretion properties. For drugs intended to treat Alzheimer's disease or other brain-targeted diseases, the ability of a drug to cross the blood brain barrier may be a key issue. Toxicology and safety studies identify potential target organs for adverse effects and define the Therapeutic Index to set the initial starting doses in clinical trials. Pivotal preclinical safety studies generally require regulatory oversight as defined by US Food and Drug Administration (FDA) Good Laboratory Practices and international guidelines, including the International Conference on Harmonisation. Concurrent preclinical development activities include developing the Clinical Plan and preparing the new drug product, including the associated documentation to meet stringent FDA Good Manufacturing Practices regulatory guidelines. A wide range of commercial and government contract options are available for investigators seeking to advance their candidate(s). Government programs such as the Small Business Innovative Research and Small Business Technology Transfer grants and the National Institutes of Health Rapid Access to Interventional Development Pilot Program provide funding and

  9. Removal of S6K1 and S6K2 Leads to Divergent Alterations in Learning, Memory, and Synaptic Plasticity

    ERIC Educational Resources Information Center

    Antion, Marcia D.; Merhav, Maayan; Hoeffer, Charles A.; Reis, Gerald; Kozma, Sara C.; Thomas, George; Schuman Erin M.; Rosenblum, Kobi; Klann, Eric

    2008-01-01

    Protein synthesis is required for the expression of enduring memories and long-lasting synaptic plasticity. During cellular proliferation and growth, S6 kinases (S6Ks) are activated and coordinate the synthesis of de novo proteins. We hypothesized that protein synthesis mediated by S6Ks is critical for the manifestation of learning, memory, and…

  10. Preclinical electrogastrography in experimental pigs

    PubMed Central

    Květina, Jaroslav; Varayil, Jithinraj Edakkanambeth; Ali, Shahzad Marghoob; Kuneš, Martin; Bureš, Jan; Tachecí, Ilja; Rejchrt, Stanislav; Kopáčová, Marcela

    2010-01-01

    Surface electrogastrography (EGG) is a non-invasive means of recording gastric myoelectric activity or slow waves from cutaneous leads placed over the stomach. This paper provides a comprehensive review of preclinical EGG. Our group recently set up and worked out the methods for EGG in experimental pigs. We gained our initial experience in the use of EGG in assessment of porcine gastric myoelectric activity after volume challenge and after intragastric administration of itopride and erythromycin. The mean dominant frequency in pigs is comparable with that found in humans. EGG in experimental pigs is feasible. Experimental EGG is an important basis for further preclinical projects in pharmacology and toxicology. PMID:21217873

  11. Ribosomal S6 kinase (RSK) modulators: a patent review.

    PubMed

    Ludwik, Katarzyna A; Lannigan, Deborah A

    2016-09-01

    The p90 ribosomal S6 kinases (RSK) are a family of Ser/Thr protein kinases that are downstream effectors of MEK1/2-ERK1/2. Increased RSK activation is implicated in the etiology of multiple pathologies, including numerous types of cancers, cardiovascular disease, liver and lung fibrosis, and infections. The review summarizes the patent and scientific literature on small molecule modulators of RSK and their potential use as therapeutics. The patents were identified using World Intellectual Property Organization and United States Patent and Trademark Office databases. The compounds described are predominantly RSK inhibitors, but a RSK activator is also described. The majority of the inhibitors are not RSK-specific. Based on the overwhelming evidence that RSK is involved in a number of diseases that have high mortalities it seems surprising that there are no RSK modulators that have pharmacokinetic properties suitable for in vivo use. MEK1/2 inhibitors are in the clinic, but the efficacy of these compounds appears to be limited by their side effects. We hypothesize that targeting the downstream effectors of MEK1/2, like RSK, are an untapped source of drug targets and that they will generate less side effects than MEK1/2 inhibitors because they regulate fewer effectors.

  12. Reform in Teaching Preclinical Pathophysiology

    ERIC Educational Resources Information Center

    Li, Yong-Yu; Li, Kun; Yao, Hong; Xu, Xiao-Juan; Cai, Qiao-Lin

    2015-01-01

    Pathophysiology is a scientific discipline that studies the onset and progression of pathological conditions and diseases, and pathophysiology is one of the core courses in most preclinical medical curricula. In China, most medical schools house a Department of Pathophysiology, in contrast to medical schools in many developed countries. The staff…

  13. Safety.

    ERIC Educational Resources Information Center

    Education in Science, 1996

    1996-01-01

    Discusses safety issues in science, including: allergic reactions to peanuts used in experiments; explosions in lead/acid batteries; and inspection of pressure vessels, such as pressure cookers or model steam engines. (MKR)

  14. First Principles Investigation of the Geometrical and Electrochemical Properties of Na4P<S6 and Li4P2S6

    NASA Astrophysics Data System (ADS)

    Rush, Larry E., Jr.; Holzwarth, N. A. W.

    First principles simulations are used to examine the structural and physical properties of Na4P2S6 in comparison with its Li4P2S6 analog. Four model structures are considered including the C 2 / m structure recently reported by Kuhn and co-workers from their analysis of single crystals of Na4P2S6, and three structures related to the P63 / mcm structure with P site disorder found in 1982 by Mercier and co-workers from their analysis of single crystals of Li4P2S6. The computational results indicate that both Na4P2S6 and Li4P2S6 have the same disordered ground state structures consistent with the P63 / mcm space group, while the optimized C 2 / m structures have higher energies by 0.1 eV and 0.4 eV per formula unit for Na4P2S6 and Li4P2S6, respectively. Simulations of ion migration suggest that Na4P2S6 may have more favorable ionic conductivity compared to Li4P2S6. Supported by NSF Grant DMR-1105485 and DMR-1507942.

  15. Mitigating risk in academic preclinical drug discovery

    PubMed Central

    Dahlin, Jayme L.; Inglese, James; Walters, Michael A.

    2018-01-01

    The number of academic drug discovery centres has grown considerably in recent years, providing new opportunities to couple the curiosity-driven research culture in academia with rigorous preclinical drug discovery practices used in industry. To fully realize the potential of these opportunities, it is important that academic researchers understand the risks inherent in preclinical drug discovery, and that translational research programmes are effectively organized and supported at an institutional level. In this article, we discuss strategies to mitigate risks in several key aspects of preclinical drug discovery at academic drug discovery centres, including organization, target selection, assay design, medicinal chemistry and preclinical pharmacology. PMID:25829283

  16. Mitigating risk in academic preclinical drug discovery.

    PubMed

    Dahlin, Jayme L; Inglese, James; Walters, Michael A

    2015-04-01

    The number of academic drug discovery centres has grown considerably in recent years, providing new opportunities to couple the curiosity-driven research culture in academia with rigorous preclinical drug discovery practices used in industry. To fully realize the potential of these opportunities, it is important that academic researchers understand the risks inherent in preclinical drug discovery, and that translational research programmes are effectively organized and supported at an institutional level. In this article, we discuss strategies to mitigate risks in several key aspects of preclinical drug discovery at academic drug discovery centres, including organization, target selection, assay design, medicinal chemistry and preclinical pharmacology.

  17. Phosphorylated ribosomal S6 (p-rpS6) as a post-treatment indicator of HER2 signalling targeted drug resistance.

    PubMed

    Yang-Kolodji, Gloria; Mumenthaler, Shannon M; Mehta, Arjun; Ji, Lingyun; Tripathy, Debu

    2015-01-01

    To identify clinically relevant predictive biomarkers of trastuzumab resistance. MTT, FACS assays, immunoblotting and immunocytochemistry were used to phenotypically characterize drug responses of two cell models BT474R and SKBR3R. Student's t-test and Spearman's correlation were applied for statistic analysis. The activity of a downstream effector of the HER2 pathway phosphorylated ribosomal protein S6 (p-rpS6), was suppressed by trastuzumab in the parental cell lines yet remained unchanged in the resistant cells following treatment. The level of p-rpS6 was inversely correlated to the drug induced growth inhibition of trastuzumab-resistant cells when they are treated with selected HER2 targeting drugs. p-rpS6 is a robust post-treatment indicator of HER2 pathway-targeted therapy resistance.

  18. Stimulation of skeletal muscle myofibrillar protein synthesis, p70 S6 kinase phosphorylation, and ribosomal protein S6 phosphorylation by inhibition of myostatin in mature mice.

    PubMed

    Welle, Stephen; Burgess, Kerri; Mehta, Sangeeta

    2009-03-01

    Knocking out myostatin activity during development increases the rate of muscle protein synthesis. The present study was done to determine whether postdevelopmental loss of myostatin activity stimulates myofibrillar protein synthesis and the phosphorylation of some of the proteins involved in regulation of protein synthesis rate. Myostatin activity was inhibited for 4 days, in 4- to 5-mo-old male mice, with injections of an anti-myostatin antibody (JA16). The mean myofibrillar synthesis rate increased 19% (P < 0.01) relative to the mean rate in saline-treated mice, as determined by incorporation of deuterium-labeled phenylalanine. JA16 increased phosphorylation of p70 S6 kinase (S6K) and ribosomal protein S6 (rpS6) 1.9-fold (P < 0.05). It did not affect phosphorylation of eukaryotic initiation factor 4E-binding protein-1 or Akt. Microarrays and real-time PCR analyses indicated that JA16 administration did not selectively enrich levels of mRNAs encoding myofibrillar proteins, ribosomal proteins, or translation initiation and elongation factors. Rapamycin treatment did not affect the rate of myofibrillar protein synthesis whether or not the mice received JA16 injections, although it eliminated the phosphorylation of S6K and rpS6. We conclude that the normal level of myostatin activity in mature muscle is sufficient to inhibit myofibrillar synthesis rate and phosphorylation of S6K and rpS6. Reversal of the inhibition of myofibrillar synthesis with an anti-myostatin antibody is not dependent on mTOR activation.

  19. Reform in teaching preclinical pathophysiology.

    PubMed

    Li, Yong-Yu; Li, Kun; Yao, Hong; Xu, Xiao-Juan; Cai, Qiao-Lin

    2015-12-01

    Pathophysiology is a scientific discipline that studies the onset and progression of pathological conditions and diseases, and pathophysiology is one of the core courses in most preclinical medical curricula. In China, most medical schools house a Department of Pathophysiology, in contrast to medical schools in many developed countries. The staff in Chinese Departments of Pathophysiology generally consists of full-time instructors or lecturers who teach medical students. These lecturers are sometimes lacking in clinic knowledge and experiences. To overcome this, in recent years, we have been trying to bring new trends in teaching pathophysiology into our curriculum. Our purpose in writing this article was to share our experiences with our colleagues and peers worldwide in the hope that the insights we have gained in pathophysiology teaching will be of some value to educators who advocate teaching reform in medical schools. Copyright © 2015 The American Physiological Society.

  20. [Preclinical study of noopept toxicity].

    PubMed

    Kovalenko, L P; Smol'nikova, N M; Alekseeva, S V; Nemova, E P; Sorokina, A V; Miramedova, M G; Kurapova, S P; Sidorina, E I; Kulakova, A V; Daugel'-Dauge, N O

    2002-01-01

    Within the framework of a preclinical investigation, the new nootrope drug noopept (N-phenyl-acetyl-L-propyl-glycine ethylate) was tested for chronic toxicity upon peroral administration in a dose of 10 or 100 mg/kg over 6 months in both male and female rabbits. The results of observations showed that noopept administered in this dose range induced no irreversible pathologic changes in the organs and systems studied and exhibited no allergenic, immunotoxic, and mutagen activity. The drug affected neither the generative function nor the antenatal or postnatal progeny development. Noopept produced a dose-dependent suppression of inflammation reaction to concanavalin A and stimulated the cellular and humoral immune response in mice.

  1. p70S6K1 (S6K1)-mediated Phosphorylation Regulates Phosphatidylinositol 4-Phosphate 5-Kinase Type I γ Degradation and Cell Invasion.

    PubMed

    Jafari, Naser; Zheng, Qiaodan; Li, Liqing; Li, Wei; Qi, Lei; Xiao, Jianyong; Gao, Tianyan; Huang, Cai

    2016-12-02

    Phosphatidylinositol 4-phosphate 5-kinase type I γ (PIPKIγ90) ubiquitination and subsequent degradation regulate focal adhesion assembly, cell migration, and invasion. However, it is unknown how upstream signals control PIPKIγ90 ubiquitination or degradation. Here we show that p70S6K1 (S6K1), a downstream target of mechanistic target of rapamycin (mTOR), phosphorylates PIPKIγ90 at Thr-553 and Ser-555 and that S6K1-mediated PIPKIγ90 phosphorylation is essential for cell migration and invasion. Moreover, PIPKIγ90 phosphorylation is required for the development of focal adhesions and invadopodia, key machineries for cell migration and invasion. Surprisingly, substitution of Thr-553 and Ser-555 with Ala promoted PIPKIγ90 ubiquitination but enhanced the stability of PIPKIγ90, and depletion of S6K1 also enhanced the stability of PIPKIγ90, indicating that PIPKIγ90 ubiquitination alone is insufficient for its degradation. These data suggest that S6K1-mediated PIPKIγ90 phosphorylation regulates cell migration and invasion by controlling PIPKIγ90 degradation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Preclinical Animal Models for Temporomandibular Joint Tissue Engineering.

    PubMed

    Almarza, Alejandro J; Brown, Bryan N; Arzi, Boaz; Ângelo, David Faustino; Chung, William; Badylak, Stephen F; Detamore, Michael

    2018-06-01

    There is a paucity of in vivo studies that investigate the safety and efficacy of temporomandibular joint (TMJ) tissue regeneration approaches, in part due to the lack of established animal models. Review of disease models for study of TMJ is presented herein with an attempt to identify relevant preclinical animal models for TMJ tissue engineering, with emphasis on the disc and condyle. Although degenerative joint disease models have been mainly performed on mice, rats, and rabbits, preclinical regeneration approaches must employ larger animal species. There remains controversy regarding the preferred choice of larger animal models between the farm pig, minipig, goat, sheep, and dog. The advantages of the pig and minipig include their well characterized anatomy, physiology, and tissue properties. The advantages of the sheep and goat are their easier surgical access, low cost per animal, and its high tissue availability. The advantage of the dog is that the joint space is confined, so migration of interpositional devices should be less likely. However, each species has limitations as well. For example, the farm pig has continuous growth until about 18 months of age, and difficult surgical access due to the zygomatic arch covering the lateral aspect of joint. The minipig is not widely available and somewhat costly. The sheep and the goat are herbivores, and their TMJs mainly function in translation. The dog is a carnivore, and the TMJ is a hinge joint that can only rotate. Although no species provides the gold standard for all preclinical TMJ tissue engineering approaches, the goat and sheep have emerged as the leading options, with the minipig as the choice when cost is less of a limitation; and with the dog and farm pig serving as acceptable alternatives. Finally, naturally occurring TMJ disorders in domestic species may be harnessed on a preclinical trial basis as a clinically relevant platform for translation.

  3. Cation–Eutectic Transition via Sublattice Melting in CuInP 2S 6/In 4/3P 2S 6 van der Waals Layered Crystals

    DOE PAGES

    Susner, Michael A.; Chyasnavichyus, Marius; Puretzky, Alexander A.; ...

    2017-07-07

    Single crystals of the van der Waals layered ferrielectric material CuInP 2S 6 spontaneously phase separate when synthesized with Cu deficiency. In this paper, we identify a route to form and tune intralayer heterostructures between the corresponding ferrielectric (CuInP 2S 6) and paraelectric (In 4/3P 2S 6) phases through control of chemical phase separation. We conclusively demonstrate that Cu-deficient Cu 1–xIn 1+x/3P 2S 6 forms a single phase at high temperature. We also identify the mechanism by which the phase separation proceeds upon cooling. Above 500 K both Cu + and In 3+ become mobile, while P 2S 6 4–more » anions maintain their structure. We therefore propose that this transition can be understood as eutectic melting on the cation sublattice. Such a model suggests that the transition temperature for the melting process is relatively low because it requires only a partial reorganization of the crystal lattice. As a result, varying the cooling rate through the phase transition controls the lateral extent of chemical domains over several decades in size. At the fastest cooling rate, the dimensional confinement of the ferrielectric CuInP 2S 6 phase to nanoscale dimensions suppresses ferrielectric ordering due to the intrinsic ferroelectric size effect. Finally, intralayer heterostructures can be formed, destroyed, and re-formed by thermal cycling, thus enabling the possibility of finely tuned ferroic structures that can potentially be optimized for specific device architectures.« less

  4. Cation–Eutectic Transition via Sublattice Melting in CuInP 2S 6/In 4/3P 2S 6 van der Waals Layered Crystals

    SciTech Connect

    Susner, Michael A.; Chyasnavichyus, Marius; Puretzky, Alexander A.

    Single crystals of the van der Waals layered ferrielectric material CuInP 2S 6 spontaneously phase separate when synthesized with Cu deficiency. In this paper, we identify a route to form and tune intralayer heterostructures between the corresponding ferrielectric (CuInP 2S 6) and paraelectric (In 4/3P 2S 6) phases through control of chemical phase separation. We conclusively demonstrate that Cu-deficient Cu 1–xIn 1+x/3P 2S 6 forms a single phase at high temperature. We also identify the mechanism by which the phase separation proceeds upon cooling. Above 500 K both Cu + and In 3+ become mobile, while P 2S 6 4–more » anions maintain their structure. We therefore propose that this transition can be understood as eutectic melting on the cation sublattice. Such a model suggests that the transition temperature for the melting process is relatively low because it requires only a partial reorganization of the crystal lattice. As a result, varying the cooling rate through the phase transition controls the lateral extent of chemical domains over several decades in size. At the fastest cooling rate, the dimensional confinement of the ferrielectric CuInP 2S 6 phase to nanoscale dimensions suppresses ferrielectric ordering due to the intrinsic ferroelectric size effect. Finally, intralayer heterostructures can be formed, destroyed, and re-formed by thermal cycling, thus enabling the possibility of finely tuned ferroic structures that can potentially be optimized for specific device architectures.« less

  5. The Preclinical Alzheimer Cognitive Composite

    PubMed Central

    Donohue, Michael C.; Sperling, Reisa A.; Salmon, David P.; Rentz, Dorene M.; Raman, Rema; Thomas, Ronald G.; Weiner, Michael; Aisen, Paul S.

    2015-01-01

    IMPORTANCE As Alzheimer disease (AD) research moves to intervene in presymptomatic phases of the disease, we must develop outcome measures sensitive to the earliest disease-related changes. OBJECTIVE To demonstrate the feasibility of a cognitive composite outcome for clinically normal elderly participants with evidence of AD pathology using the ADCS Preclinical Alzheimer Cognitive Composite (ADCS-PACC). The ADCS-PACC combines tests that assess episodic memory, timed executive function, and global cognition. The ADCS-PACC is the primary outcome measure for the first clinical trial in preclinical AD (ie, the Anti-Amyloid Treatment in Asymptomatic Alzheimer’s study). DESIGN, SETTING, AND PARTICIPANTS With the ADCS-PACC, we derive pilot estimates of amyloid-related decline using data from 2 observational studies conducted in North America and another conducted in Australia. The participants analyzed had normal cognition and mean ages of 75.81, 71.37, and 79.42 years across the 3 studies. MAIN OUTCOMES AND MEASURES For the 2 studies that collected data on Aβ levels (ADNI and AIBL), we estimate decline in a preclinical AD “Aβ-positive” placebo group and compare them with an “Aβ-negative” group. For the study that did not include data on Aβ levels (the ADCS Prevention Instrument [ADCS-PI] study), we grouped participants by the presence of APOE-ɛ4 and by clinical progression. RESULTS In ADNI, Aβ-positive participants showed more decline than did Aβ-negative participants with regard to the ADCS-PACC score at 24 months (mean [SE] difference, −1.239 [0.522] [95% CI, −2.263 to −0.215]; P = .02). In AIBL, the mean (SE) difference is significant at both 18 months (−1.009 [0.406] [95% CI, −1.805 to −0.213]; P = .01) and 36 months (−1.404 [0.452] [95% CI, −2.290 to −0.519]; P = .002). In the ADCS-PI study, APOE-ɛ4 allele carriers performed significantly worse on the ADCS-PACC at 24 months (mean [SE] score, −0.742 [0.294] [95% CI, −1.318 to

  6. 8 CFR 1236.4 - Removal of S-5, S-6, and S-7 nonimmigrants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Removal of S-5, S-6, and S-7 nonimmigrants. 1236.4 Section 1236.4 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF... OF ALIENS ORDERED REMOVED Detention of Aliens Prior to Order of Removal § 1236.4 Removal of S-5, S-6...

  7. 8 CFR 236.4 - Removal of S-5, S-6, and S-7 nonimmigrants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Removal of S-5, S-6, and S-7 nonimmigrants. 236.4 Section 236.4 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS... of Aliens Prior to Order of Removal § 236.4 Removal of S-5, S-6, and S-7 nonimmigrants. (a) Condition...

  8. Involvement of S6K1 in mitochondria function and structure in HeLa cells.

    PubMed

    Park, Jisoo; Tran, Quangdon; Mun, Kisun; Masuda, Kouhei; Kwon, So Hee; Kim, Seon-Hwan; Kim, Dong-Hoon; Thomas, George; Park, Jongsun

    2016-12-01

    The major biological function of mitochondria is to generate cellular energy through oxidative phosphorylation. Apart from cellular respiration, mitochondria also play a key role in signaling processes, including aging and cancer metabolism. It has been shown that S6K1-knockout mice are resistant to obesity due to enhanced beta-oxidation, with an increased number of large mitochondria. Therefore, in this report, the possible involvement of S6K1 in regulating mitochondria dynamics and function has been investigated in stable lenti-shS6K1-HeLa cells. Interestingly, S6K1-stably depleted HeLa cells showed phenotypical changes in mitochondria morphology. This observation was further confirmed by detailed image analysis of mitochondria shape. Corresponding molecular changes were also observed in these cells, such as the induction of mitochondrial fission proteins (Drp1 and Fis1). Oxygen consumption is elevated in S6K1-depeleted HeLa cells and FL5.12 cells. In addition, S6K1 depletion leads to enhancement of ATP production in cytoplasm and mitochondria. However, the relative ratio of mitochondrial ATP to cytoplasmic ATP is actually decreased in lenti-shS6K1-HeLa cells compared to control cells. Lastly, induction of mitophagy was found in lenti-shS6K1-HeLa cells with corresponding changes of mitochondria shape on electron microscope analysis. Taken together, our results indicate that S6K1 is involved in the regulation of mitochondria morphology and function in HeLa cells. This study will provide novel insights into S6K1 function in mitochondria-mediated cellular signaling. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Preclinical studies of dendrimer prodrugs.

    PubMed

    Kojima, Chie

    2015-01-01

    Dendrimers are synthetic macromolecules with well-defined structures bearing a wide variety of functional groups on their periphery. These groups can be used to conjugate bioactive molecules such as drugs, ligands and imaging agents. Dendrimer prodrugs can be used to improve the water solubility and pharmacokinetic properties of the corresponding free drugs. This article summarizes preclinical studies pertaining to the use of drug-dendrimer conjugates as dendrimer prodrugs for the treatments of various diseases, including cancer and inflammatory diseases. A wide range of anticancer drugs have been conjugated to dendrimers via biodegradable linkers. The side effects of the parent drugs can be markedly reduced using dendrimer prodrugs, with some drugs showing improved efficacy. Anti-inflammatory agents have also been conjugated to dendrimers and used to treat a number of inflammatory diseases. Drug-dendrimer conjugates are preferable to drug-dendrimer complexes, where the use of degradable linkers is critical to the release of the drug. Polyethylene glycol and/or ligands can be added to a dendrimer prodrug, which is useful for the targeting of affected tissues. Imaging probes can also be incorporated into dendrimer prodrugs for the simultaneous delivery of therapeutic and diagnostic agents as 'theranostics.'

  10. Preclinical models for obesity research

    PubMed Central

    Barrett, Perry; Morgan, Peter J.

    2016-01-01

    ABSTRACT A multi-dimensional strategy to tackle the global obesity epidemic requires an in-depth understanding of the mechanisms that underlie this complex condition. Much of the current mechanistic knowledge has arisen from preclinical research performed mostly, but not exclusively, in laboratory mouse and rat strains. These experimental models mimic certain aspects of the human condition and its root causes, particularly the over-consumption of calories and unbalanced diets. As with human obesity, obesity in rodents is the result of complex gene–environment interactions. Here, we review the traditional monogenic models of obesity, their contemporary optogenetic and chemogenetic successors, and the use of dietary manipulations and meal-feeding regimes to recapitulate the complexity of human obesity. We critically appraise the strengths and weaknesses of these different models to explore the underlying mechanisms, including the neural circuits that drive behaviours such as appetite control. We also discuss the use of these models for testing and screening anti-obesity drugs, beneficial bio-actives, and nutritional strategies, with the goal of ultimately translating these findings for the treatment of human obesity. PMID:27821603

  11. Characterization of a phorbol ester-stimulated S6 kinase from MDCK renal epithelial cells

    SciTech Connect

    Meier, K.E.; Krebs, E.G.

    Increased phosphorylation of S6, a 40S ribosomal subunit protein, is observed in mammalian cells in response to growth factors and phorbol esters. The goal of this study was to identify the S6 kinase that is stimulated by phorbol ester treatment of MDCK cells. MDCK clone D1 cells express high levels of protein kinase C(PKC). PKC and S6 kinase activities were measured following DEAE-Sephacel fractionation of cytosol; this procedure separated the two kinase activities. When confluent MDCK-D1 cells were exposed to 100 nM phorbol 12-myristate 13-acetate (PMA), 95% of the total cellular PKC activity became associated with the particulate fraction withinmore » 1 hour. Cytosolic S6 kinase activity was maximal by 1 hour and then declined thereafter, preceding any detectable loss of total cellular PKC. The PMA-responsive S6 kinase was partially purified from MDCK-D1 cytosol by consecutive steps of DEAE-Sephacel, ammonium sulfate precipitation, Ultrogel AcA 34, heparin-agarose, and Ultrogel AcA 34. The partially-purified enzyme had an apparent molecular size of approximately 80 kDa. In addition to S6, the enzyme phosphorylated synthetic peptides based on the carboxyl terminal sequence of S6. S6 kinase activity utilized ATP but not GTP, and was inhibited by heparin, NaCl, and ..beta..-glycerophosphate. In conclusion, a phorbol ester-stimulated S6 kinase has been partially purified from an epithelial cell line. This kinase is distinct from PKC.« less

  12. Targeting Aberrant p70S6K Activation for Estrogen Receptor-Negative Breast Cancer Prevention.

    PubMed

    Wang, Xiao; Yao, Jun; Wang, Jinyang; Zhang, Qingling; Brady, Samuel W; Arun, Banu; Seewaldt, Victoria L; Yu, Dihua

    2017-11-01

    The prevention of estrogen receptor-negative (ER-) breast cancer remains a major challenge in the cancer prevention field, although antiestrogen and aromatase inhibitors have shown adequate efficacy in preventing estrogen receptor-positive (ER + ) breast cancer. Lack of commonly expressed, druggable targets is a major obstacle for meeting this challenge. Previously, we detected the activation of Akt signaling pathway in atypical hyperplasic early-stage lesions of patients. In the current study, we found that Akt and the downstream 70 kDa ribosomal protein S6 kinase (p70S6K) signaling pathway was highly activated in ER - premalignant breast lesions and ER - breast cancer. In addition, p70S6K activation induced transformation of ER - human mammary epithelial cells (hMEC). Therefore, we explored the potential of targeting Akt/p70S6K in the p70S6K activated, ER - hMEC models and mouse mammary tumor models for the prevention of ER - breast cancer. We found that a clinically applicable Akt/p70S6K dual inhibitor, LY2780301, drastically decreased proliferation of hMECs with ErbB2-induced p70S6K activation via Cyclin B1 inhibition and cell-cycle blockade at G 0 -G 1 phase, while it did not significantly reverse the abnormal acinar morphology of these hMECs. In addition, a brief treatment of LY2780301 in MMTV- neu mice that developed atypical hyperplasia (ADH) and mammary intraepithelial neoplasia (MIN) lesions with activated p70S6K was sufficient to suppress S6 phosphorylation and decrease cell proliferation in hyperplasic MECs. In summary, targeting the aberrant Akt/p70S6K activation in ER - hMEC models in vitro and in the MMTV- neu transgenic mouse model in vivo effectively inhibited Akt/S6K signaling and reduced proliferation of hMECs in vitro and ADH/MIN lesions in vivo , indicating its potential in prevention of p70S6K activated ER - breast cancer. Cancer Prev Res; 10(11); 641-50. ©2017 AACR . ©2017 American Association for Cancer Research.

  13. Preclinical neuroprotective actions of xenon and possible implications for human therapeutics: a narrative review.

    PubMed

    Maze, Mervyn

    2016-02-01

    The purpose of this report is to facilitate an understanding of the possible application of xenon for neuroprotection in critical care settings. This narrative review appraises the literature assessing the efficacy and safety of xenon in preclinical models of acute ongoing neurologic injury. Databases of the published literature (MEDLINE® and EMBASE™) were appraised for peer-reviewed manuscripts addressing the use of xenon in both preclinical models and disease states of acute ongoing neurologic injury. For randomized clinical trials not yet reported, the investigators' declarations in the National Institutes of Health clinical trials website were considered. While not a primary focus of this review, to date, xenon cannot be distinguished as superior for surgical anesthesia over existing alternatives in adults. Nevertheless, studies in a variety of preclinical disease models from multiple laboratories have consistently shown xenon's neuroprotective properties. These properties are enhanced in settings where xenon is combined with hypothermia. Small randomized clinical trials are underway to explore xenon's efficacy and safety in clinical settings of acute neurologic injury where hypothermia is the current standard of care. According to the evidence to date, the neuroprotective efficacy of xenon in preclinical models and its safety in clinical anesthesia set the stage for the launch of randomized clinical trials to determine whether these encouraging neuroprotective findings can be translated into clinical utility.

  14. Growth Inhibition by Bupivacaine Is Associated with Inactivation of Ribosomal Protein S6 Kinase 1

    PubMed Central

    Beigh, Mushtaq Ahmad; Showkat, Mehvish; Bashir, Basharat; Bashir, Asma; Hussain, Mahboob ul; Andrabi, Khurshid Iqbal

    2014-01-01

    Bupivacaine is an amide type long acting local anesthetic used for epidural anesthesia and nerve blockade in patients. Use of bupivacaine is associated with severe cytotoxicity and apoptosis along with inhibition of cell growth and proliferation. Although inhibition of Erk, Akt, and AMPK seemingly appears to mediate some of the bupivacaine effects, potential downstream targets that mediate its effect remain unknown. S6 kinase 1 is a common downstream effector of several growth regulatory pathways involved in cell growth and proliferation known to be affected by bupivacaine. We have accordingly attempted to relate the growth inhibitory effects of bupivacaine with the status of S6K1 activity and we present evidence that decrease in cell growth and proliferation by bupivacaine is mediated through inactivation of S6 kinase 1 in a concentration and time dependent manner. We also show that ectopic expression of constitutively active S6 kinase 1 imparts substantial protection from bupivacaine induced cytotoxicity. Inactivation of S6K1 though associated with loss of putative mTOR mediated phosphorylation did not correspond with loss of similar phosphorylations in 4EBP1 indicating that S6K1 inhibition was not mediated through inactivation of mTORC1 signaling pathway or its down regulation. PMID:24605337

  15. Methodological Rigor in Preclinical Cardiovascular Studies

    PubMed Central

    Ramirez, F. Daniel; Motazedian, Pouya; Jung, Richard G.; Di Santo, Pietro; MacDonald, Zachary D.; Moreland, Robert; Simard, Trevor; Clancy, Aisling A.; Russo, Juan J.; Welch, Vivian A.; Wells, George A.

    2017-01-01

    Rationale: Methodological sources of bias and suboptimal reporting contribute to irreproducibility in preclinical science and may negatively affect research translation. Randomization, blinding, sample size estimation, and considering sex as a biological variable are deemed crucial study design elements to maximize the quality and predictive value of preclinical experiments. Objective: To examine the prevalence and temporal patterns of recommended study design element implementation in preclinical cardiovascular research. Methods and Results: All articles published over a 10-year period in 5 leading cardiovascular journals were reviewed. Reports of in vivo experiments in nonhuman mammals describing pathophysiology, genetics, or therapeutic interventions relevant to specific cardiovascular disorders were identified. Data on study design and animal model use were collected. Citations at 60 months were additionally examined as a surrogate measure of research impact in a prespecified subset of studies, stratified by individual and cumulative study design elements. Of 28 636 articles screened, 3396 met inclusion criteria. Randomization was reported in 21.8%, blinding in 32.7%, and sample size estimation in 2.3%. Temporal and disease-specific analyses show that the implementation of these study design elements has overall not appreciably increased over the past decade, except in preclinical stroke research, which has uniquely demonstrated significant improvements in methodological rigor. In a subset of 1681 preclinical studies, randomization, blinding, sample size estimation, and inclusion of both sexes were not associated with increased citations at 60 months. Conclusions: Methodological shortcomings are prevalent in preclinical cardiovascular research, have not substantially improved over the past 10 years, and may be overlooked when basing subsequent studies. Resultant risks of bias and threats to study validity have the potential to hinder progress in

  16. Identification of a Calcium Signalling Pathway of S-[6]-Gingerol in HuH-7 Cells.

    PubMed

    Li, Xiao-Hong; McGrath, Kristine C Y; Tran, Van H; Li, Yi-Ming; Mandadi, Sravan; Duke, Colin C; Heather, Alison K; Roufogalis, Basil D

    2013-01-01

    Calcium signals in hepatocytes control cell growth, proliferation, and death. Members of the transient receptor potential (TRP) cation channel superfamily are candidate calcium influx channels. NF κ B activation strictly depends on calcium influx and often induces antiapoptotic genes favouring cell survival. Previously, we reported that S-[6]-gingerol is an efficacious agonist of the transient receptor potential cation channel subfamily V member 1 (TRPV1) in neurones. In this study, we tested the effect of S-[6]-gingerol on HuH-7 cells using the Fluo-4 calcium assay, RT-qPCR, transient cell transfection, and luciferase measurements. We found that S-[6]-gingerol induced a transient rise in [Ca(2+)] i in HuH-7 cells. The increase in [Ca(2+)] i induced by S-[6]-gingerol was abolished by preincubation with EGTA and was also inhibited by the TRPV1 channel antagonist capsazepine. Expression of TRPV1 in HuH-7 cells was confirmed by mRNA analysis as well as a test for increase of [Ca(2+)] i by TRPV1 agonist capsaicin and its inhibition by capsazepine. We found that S-[6]-gingerol induced rapid NF κ B activation through TRPV1 in HuH-7 cells. Furthermore, S-[6]-gingerol-induced NF κ B activation was dependent on the calcium gradient and TRPV1. The rapid NF κ B activation by S-[6]-gingerol was associated with an increase in mRNA levels of NF κ B-target genes: cIAP-2, XIAP, and Bcl-2 that encode antiapoptotic proteins.

  17. Dissolution DNP for in vivo preclinical studies

    NASA Astrophysics Data System (ADS)

    Comment, Arnaud

    2016-03-01

    The tremendous polarization enhancement afforded by dissolution dynamic nuclear polarization (DNP) can be taken advantage of to perform preclinical in vivo molecular and metabolic imaging. Following the injection of molecules that are hyperpolarized via dissolution DNP, real-time measurements of their biodistribution and metabolic conversion can be recorded. This technology therefore provides a unique and invaluable tool for probing cellular metabolism in vivo in animal models in a noninvasive manner. It gives the opportunity to follow and evaluate disease progression and treatment response without requiring ex vivo destructive tissue assays. Although its considerable potential has now been widely recognized, hyperpolarized magnetic resonance by dissolution DNP remains a challenging method to implement for routine in vivo preclinical measurements. The aim of this article is to provide an overview of the current state-of-the-art technology for preclinical applications and the challenges that need to be addressed to promote it and allow its wider dissemination in the near future.

  18. S6K1 Is Required for Increasing Skeletal Muscle Force during Hypertrophy.

    PubMed

    Marabita, Manuela; Baraldo, Martina; Solagna, Francesca; Ceelen, Judith Johanna Maria; Sartori, Roberta; Nolte, Hendrik; Nemazanyy, Ivan; Pyronnet, Stéphane; Kruger, Marcus; Pende, Mario; Blaauw, Bert

    2016-10-04

    Loss of skeletal muscle mass and force aggravates age-related sarcopenia and numerous pathologies, such as cancer and diabetes. The AKT-mTORC1 pathway plays a major role in stimulating adult muscle growth; however, the functional role of its downstream mediators in vivo is unknown. Here, we show that simultaneous inhibition of mTOR signaling to both S6K1 and 4E-BP1 is sufficient to reduce AKT-induced muscle growth and render it insensitive to the mTORC1-inhibitor rapamycin. Surprisingly, lack of mTOR signaling to 4E-BP1 only, or deletion of S6K1 alone, is not sufficient to reduce muscle hypertrophy or alter its sensitivity to rapamycin. However, we report that, while not required for muscle growth, S6K1 is essential for maintaining muscle structure and force production. Hypertrophy in the absence of S6K1 is characterized by compromised ribosome biogenesis and the formation of p62-positive protein aggregates. These findings identify S6K1 as a crucial player for maintaining muscle function during hypertrophy. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Rapamycin modulation of p70 S6 kinase signaling inhibits Rift Valley fever virus pathogenesis.

    PubMed

    Bell, Todd M; Espina, Virginia; Senina, Svetlana; Woodson, Caitlin; Brahms, Ashwini; Carey, Brian; Lin, Shih-Chao; Lundberg, Lindsay; Pinkham, Chelsea; Baer, Alan; Mueller, Claudius; Chlipala, Elizabeth A; Sharman, Faye; de la Fuente, Cynthia; Liotta, Lance; Kehn-Hall, Kylene

    2017-07-01

    Despite over 60 years of research on antiviral drugs, very few are FDA approved to treat acute viral infections. Rift Valley fever virus (RVFV), an arthropod borne virus that causes hemorrhagic fever in severe cases, currently lacks effective treatments. Existing as obligate intracellular parasites, viruses have evolved to manipulate host cell signaling pathways to meet their replication needs. Specifically, translation modulation is often necessary for viruses to establish infection in their host. Here we demonstrated phosphorylation of p70 S6 kinase, S6 ribosomal protein, and eIF4G following RVFV infection in vitro through western blot analysis and in a mouse model of infection through reverse phase protein microarrays (RPPA). Inhibition of p70 S6 kinase through rapamycin treatment reduced viral titers in vitro and increased survival and mitigated clinical disease in RVFV challenged mice. Additionally, the phosphorylation of p70 S6 kinase was decreased following rapamycin treatment in vivo. Collectively these data demonstrate modulating p70 S6 kinase can be an effective antiviral strategy. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Preclinical safety evaluation of intravenously administered mixed micelles.

    PubMed

    Teelmann, K; Schläppi, B; Schüpbach, M; Kistler, A

    1984-01-01

    Mixed micelles, with their main constituents lecithin and glycocholic acid, form a new principle for the parenteral administration of compounds which are poorly water-soluble. Their composition of mainly physiological substances as well as their comparatively good stability substantiate their attractivity in comparison to existing solvents. A decomposition due to physical influences such as heat or storage for several years will almost exclusively affect the lecithin component in the form of hydrolysis into free fatty acids and lysolecithin. Their toxicity was examined experimentally in various studies using both undecomposed and artificially decomposed mixed micelles. In these studies the mixed micelles were locally and systemically well tolerated and proved to be neither embryotoxic, teratogenic nor mutagenic. Only when comparatively high doses of the undecomposed mixed micelles were administered, corresponding to approximately 30 to 50 times the anticipated clinical injection volume (of e.g. diazepam mixed micelles), did some vomitus (dogs), slight liver enzyme elevation (rats and dogs), and slightly increased liver weights (dogs) occur. After repeated injections of the artificially decomposed formulation (approximately 25% of lecithin hydrolyzed to free fatty acids and lysolecithin) effects such as intravascular haemolysis, liver enzyme elevations and intrahepatic cholestasis (dogs only) were observed but only when doses exceeding a threshold of approximately 40 to 60 mg lysolecithin/kg body weight were administered. All alterations were reversible after cessation of treatment.

  1. Blocking rpS6 Phosphorylation Exacerbates Tsc1 Deletion–Induced Kidney Growth

    PubMed Central

    Wu, Huijuan; Chen, Jianchun; Xu, Jinxian; Dong, Zheng; Meyuhas, Oded

    2016-01-01

    The molecular mechanisms underlying renal growth and renal growth–induced nephron damage remain poorly understood. Here, we report that in murine models, deletion of the tuberous sclerosis complex protein 1 (Tsc1) in renal proximal tubules induced strikingly enlarged kidneys, with minimal cystogenesis and occasional microscopic tumorigenesis. Signaling studies revealed hyperphosphorylation of eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) and increased phosphorylation of ribosomal protein S6 (rpS6) in activated renal tubules. Notably, knockin of a nonphosphorylatable rpS6 in these Tsc1-mutant mice exacerbated cystogenesis and caused drastic nephron damage and renal fibrosis, leading to kidney failure and a premature death rate of 67% by 9 weeks of age. In contrast, Tsc1 single-mutant mice were all alive and had far fewer renal cysts at this age. Mechanistic studies revealed persistent activation of mammalian target of rapamycin complex 1 (mTORC1) signaling causing hyperphosphorylation and consequent accumulation of 4E-BP1, along with greater cell proliferation, in the renal tubules of Tsc1 and rpS6 double-mutant mice. Furthermore, pharmacologic treatment of Tsc1 single-mutant mice with rapamycin reduced hyperphosphorylation and accumulation of 4E-BP1 but also inhibited phosphorylation of rpS6. Rapamycin also exacerbated cystic and fibrotic lesions and impaired kidney function in these mice, consequently leading to a premature death rate of 40% within 2 weeks of treatment, despite destroying tumors and decreasing kidney size. These findings indicate that Tsc1 prevents aberrant renal growth and tumorigenesis by inhibiting mTORC1 signaling, whereas phosphorylated rpS6 suppresses cystogenesis and fibrosis in Tsc1-deleted kidneys. PMID:26296742

  2. S6K1 is involved in polyploidization through its phosphorylation at Thr421/Ser424.

    PubMed

    Ma, Dongchu; Yu, Huiying; Lin, Di; Sun, Yinghui; Liu, Liping; Liu, Yage; Dai, Bing; Chen, Wei; Cao, Jianping

    2009-04-01

    Studies on polyploidization of megakaryocytes have been hampered by the lack of synchronized polyploid megakaryocytes. In this study, a relatively synchronized polyploid cell model was successfully established by employing Dami cells treated with nocodazole. In nocodazole-induced cells, cyclin B expression oscillated normally as in diploid cells and polyploid megakaryocytes. By using the nocodazole-induced Dami cell model, we found that 4E-BP1 and Thr421/Ser424 of ribosomal S6 kinase 1(S6K1) were phosphorylated mostly at M-phase in cytoplasm and oscillated in nocodazole-induced polyploid Dami cells, concomitant with increased expression of p27 and cyclin D3. However, phosphorylation of 4E-BP1 and S6K1 on Thr421/Ser424 was significantly decreased in differentiated Dami cells induced by phorbol 12-myristate 13-acetate (PMA), concomitant with increased expression of cyclin D1 and p21 and cyclin D3. Overexpression of the kinase dead form of S6K1 containing the mutation Lys 100 --> Gln in PMA-induced Dami cells increased ploidy whereas overexpression of rapamycin-resistant form of S6K1 containing the mutations Thr421 --> Glu and Ser424 --> Asp significantly dephosphorylated 4E-BP1 and reduced expression of cyclin D1, cyclin D3, p21 and p27, and slightly decreased the ploidy of PMA-induced Dami cells, compared with treatment with PMA alone. Moreover, overexpression of rapamycin-resistant form of S6K1 significantly reversed polyploidization of nocodazole-induced Dami cells. Furthermore, MAP (a novel compound synthesized recently) partly blocked the phosphorylation of S6K1 on Thr421/Ser424 and decreased the expression of p27 and polyploidization in nocodazole-induced Dami cells. Taken together, these data suggested that S6K1/4E-BP1 pathway may play an important role in polyploidization of megakaryocytes. (c) 2008 Wiley-Liss, Inc.

  3. Recommendations for Benchmarking Preclinical Studies of Nanomedicines.

    PubMed

    Dawidczyk, Charlene M; Russell, Luisa M; Searson, Peter C

    2015-10-01

    Nanoparticle-based delivery systems provide new opportunities to overcome the limitations associated with traditional small-molecule drug therapy for cancer and to achieve both therapeutic and diagnostic functions in the same platform. Preclinical trials are generally designed to assess therapeutic potential and not to optimize the design of the delivery platform. Consequently, progress in developing design rules for cancer nanomedicines has been slow, hindering progress in the field. Despite the large number of preclinical trials, several factors restrict comparison and benchmarking of different platforms, including variability in experimental design, reporting of results, and the lack of quantitative data. To solve this problem, we review the variables involved in the design of preclinical trials and propose a protocol for benchmarking that we recommend be included in in vivo preclinical studies of drug-delivery platforms for cancer therapy. This strategy will contribute to building the scientific knowledge base that enables development of design rules and accelerates the translation of new technologies. ©2015 American Association for Cancer Research.

  4. Highly efficient acousto-optic diffraction in Sn2P2S6 crystals.

    PubMed

    Martynyuk-Lototska, I Yu; Mys, O G; Grabar, A A; Stoika, I M; Vysochanskii, Yu M; Vlokh, R O

    2008-01-01

    We have studied the acousto-optic (AO) diffraction in Sn2P2S6 crystals and found that they manifest high values of an AO figure of merit. The above crystals may therefore be used as highly efficient materials in different AO applications.

  5. Rapamycin has paradoxical effects on S6 phosphorylation in rats with and without seizures.

    PubMed

    Chen, Linglin; Hu, Lin; Dong, Jing-Yin; Ye, Qing; Hua, Nan; Wong, Michael; Zeng, Ling-Hui

    2012-11-01

      Accumulating data have demonstrated that seizures induced by kainate (KA) or pilocarpine activate the mammalian target of rapamycin (mTOR) pathway and that mTOR inhibitor rapamycin can inhibit mTOR activation, which subsequently has potential antiepileptic effects. However, a preliminary study showed a paradoxical exacerbation of increased mTOR pathway activity reflected by S6 phosphorylation when rapamycin was administrated within a short period before KA injection. In the present study, we examined this paradoxical effect of rapamycin in more detail, both in normal rats and KA-injected animals.   Normal rats or KA-treated rats pretreated with rapamycin at different time intervals were sacrificed at various time points (1, 3, 6, 10, 15, and 24 h) after rapamycin administration or seizure onset for western blotting analysis. Phosphorylation of mTOR signaling target of Akt, mTOR, Rictor, Raptor, S6K, and S6 were analyzed. Seizure activity was monitored behaviorally and graded according to a modified Racine scale (n = 6 for each time point). Neuronal cell death was detected by Fluoro-Jade B staining.   In normal rats, we found that rapamycin showed the expected dose-dependent inhibition of S6 phosphorylation 3-24 h after injection, whereas a paradoxical elevation of S6 phosphorylation was observed 1 h after rapamycin. Similarly, pretreatment with rapamycin over 10 h before KA inhibited the KA seizure-induced mTOR activation. In contrast, rapamycin administered 1-6 h before KA caused a paradoxical increase in the KA seizure-induced mTOR activation. Rats pretreated with rapamycin 1 h prior to KA exhibited an increase in severity and duration of seizures and more neuronal cell death as compared to vehicle-treated groups. In contrast, rapamycin pretreated 10 h prior to KA had no effect on the seizures and decreased neuronal cell death. The paradoxical effect of rapamycin on S6 phosphorylation was correlated with upstream mTOR signaling and was

  6. Rapamycin has Paradoxical Effects on S6 Phosphorylation in Rats With and Without Seizures

    PubMed Central

    Chen, Linglin; Hu, Lin; Dong, Jing-Yin; Ye, Qing; Hua, Nan; Wong, Michael; Zeng, Ling-Hui

    2012-01-01

    Summary Purpose Accumulating data have demonstrated that seizures induced by kainate (KA) or pilocarpine activate the mammalian target of rapamycin (mTOR) pathway and mTOR inhibitor rapamycin can inhibit mTOR activation which subsequently has potential anti-epileptic effects. However, a preliminary study showed a paradoxical exacerbation of increased mTOR pathway activity reflected by S6 phosphorylation when rapamycin was administrated within a short period before KA injection. In the present study, we examined this paradoxical effect of rapamycin in more detail, both in normal rats and KA-injected animals. Methods Normal Rats or KA-treated rats pretreated with rapamycin at different time interval were sacrificed at various time points (1h, 3h, 6h, 10h, 15h and 24h) after rapamycin administration or seizure onset for Western blotting analysis. Phosphorylation of mTOR signaling target of Akt, mTOR, Rictor, Raptor, S6K and S6 were analyzed. Seizure activity was monitored behaviorally and graded according to a modified Racine scale (n=6 for each time point). Neuronal cell death was detected by Fluoro-Jade B staining. Key findings In normal rats, we found that rapamycin showed the expected dose-dependent inhibition of S6 phosphorylation 3–24 h after injection, while a paradoxical elevation of S6 phosphorylation was observed 1 hour after rapamycin. Similarly, pretreatment with rapamycin over 10 h prior to KA inhibited the KA seizure induced mTOR activation. In contrast, rapamycin administered 1 to 6 hours before KA caused a paradoxical increase in the KA seizure-induced mTOR activation. Rats pretreated with rapamycin 1 h prior to KA exhibited an increase in severity and duration of seizures and more neuronal cell death as compared to vehicle treated groups. In contrast, rapamycin pretreated 10 h prior to KA had no effect on the seizures and decreased neuronal cell death. The paradoxical effect of rapamycin on S6 phosphorylation was correlated with upstream m

  7. A Novel (S)-6-Hydroxynicotine Oxidase Gene from Shinella sp. Strain HZN7

    PubMed Central

    Qiu, Jiguo; Wei, Yin; Ma, Yun; Wen, Rongti; Wen, Yuezhong

    2014-01-01

    Nicotine is an important environmental toxicant in tobacco waste. Shinella sp. strain HZN7 can metabolize nicotine into nontoxic compounds via variations of the pyridine and pyrrolidine pathways. However, the catabolic mechanism of this variant pathway at the gene or enzyme level is still unknown. In this study, two 6-hydroxynicotine degradation-deficient mutants, N7-M9 and N7-W3, were generated by transposon mutagenesis. The corresponding mutant genes, designated nctB and tnp2, were cloned and analyzed. The nctB gene encodes a novel flavin adenine dinucleotide-containing (S)-6-hydroxynicotine oxidase that converts (S)-6-hydroxynicotine into 6-hydroxy-N-methylmyosmine and then spontaneously hydrolyzes into 6-hydroxypseudooxynicotine. The deletion and complementation of the nctB gene showed that this enzyme is essential for nicotine or (S)-6-hydroxynicotine degradation. Purified NctB could also convert (S)-nicotine into N-methylmyosmine, which spontaneously hydrolyzed into pseudooxynicotine. The kinetic constants of NctB toward (S)-6-hydroxynicotine (Km = 0.019 mM, kcat = 7.3 s−1) and nicotine (Km = 2.03 mM, kcat = 0.396 s−1) indicated that (S)-6-hydroxynicotine is the preferred substrate in vivo. NctB showed no activities toward the R enantiomer of nicotine or 6-hydroxynicotine. Strain HZN7 could degrade (R)-nicotine into (R)-6-hydroxynicotine without any further degradation. The tnp2 gene from mutant N7-W3 encodes a putative transposase, and its deletion did not abolish the nicotine degradation activity. This study advances the understanding of the microbial diversity of nicotine biodegradation. PMID:25002425

  8. A novel (S)-6-hydroxynicotine oxidase gene from Shinella sp. strain HZN7.

    PubMed

    Qiu, Jiguo; Wei, Yin; Ma, Yun; Wen, Rongti; Wen, Yuezhong; Liu, Weiping

    2014-09-01

    Nicotine is an important environmental toxicant in tobacco waste. Shinella sp. strain HZN7 can metabolize nicotine into nontoxic compounds via variations of the pyridine and pyrrolidine pathways. However, the catabolic mechanism of this variant pathway at the gene or enzyme level is still unknown. In this study, two 6-hydroxynicotine degradation-deficient mutants, N7-M9 and N7-W3, were generated by transposon mutagenesis. The corresponding mutant genes, designated nctB and tnp2, were cloned and analyzed. The nctB gene encodes a novel flavin adenine dinucleotide-containing (S)-6-hydroxynicotine oxidase that converts (S)-6-hydroxynicotine into 6-hydroxy-N-methylmyosmine and then spontaneously hydrolyzes into 6-hydroxypseudooxynicotine. The deletion and complementation of the nctB gene showed that this enzyme is essential for nicotine or (S)-6-hydroxynicotine degradation. Purified NctB could also convert (S)-nicotine into N-methylmyosmine, which spontaneously hydrolyzed into pseudooxynicotine. The kinetic constants of NctB toward (S)-6-hydroxynicotine (Km = 0.019 mM, kcat = 7.3 s(-1)) and nicotine (Km = 2.03 mM, kcat = 0.396 s(-1)) indicated that (S)-6-hydroxynicotine is the preferred substrate in vivo. NctB showed no activities toward the R enantiomer of nicotine or 6-hydroxynicotine. Strain HZN7 could degrade (R)-nicotine into (R)-6-hydroxynicotine without any further degradation. The tnp2 gene from mutant N7-W3 encodes a putative transposase, and its deletion did not abolish the nicotine degradation activity. This study advances the understanding of the microbial diversity of nicotine biodegradation. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  9. Preclinical Studies for Cartilage Repair

    PubMed Central

    Hurtig, Mark B.; Buschmann, Michael D.; Fortier, Lisa A.; Hoemann, Caroline D.; Hunziker, Ernst B.; Jurvelin, Jukka S.; Mainil-Varlet, Pierre; McIlwraith, C. Wayne; Sah, Robert L.; Whiteside, Robert A.

    2011-01-01

    Investigational devices for articular cartilage repair or replacement are considered to be significant risk devices by regulatory bodies. Therefore animal models are needed to provide proof of efficacy and safety prior to clinical testing. The financial commitment and regulatory steps needed to bring a new technology to clinical use can be major obstacles, so the implementation of highly predictive animal models is a pressing issue. Until recently, a reductionist approach using acute chondral defects in immature laboratory species, particularly the rabbit, was considered adequate; however, if successful and timely translation from animal models to regulatory approval and clinical use is the goal, a step-wise development using laboratory animals for screening and early development work followed by larger species such as the goat, sheep and horse for late development and pivotal studies is recommended. Such animals must have fully organized and mature cartilage. Both acute and chronic chondral defects can be used but the later are more like the lesions found in patients and may be more predictive. Quantitative and qualitative outcome measures such as macroscopic appearance, histology, biochemistry, functional imaging, and biomechanical testing of cartilage, provide reliable data to support investment decisions and subsequent applications to regulatory bodies for clinical trials. No one model or species can be considered ideal for pivotal studies, but the larger animal species are recommended for pivotal studies. Larger species such as the horse, goat and pig also allow arthroscopic delivery, and press-fit or sutured implant fixation in thick cartilage as well as second look arthroscopies and biopsy procedures. PMID:26069576

  10. Balancing animal welfare and assisted reproduction: ethics of preclinical animal research for testing new reproductive technologies.

    PubMed

    Jans, Verna; Dondorp, Wybo; Goossens, Ellen; Mertes, Heidi; Pennings, Guido; de Wert, Guido

    2018-02-07

    In the field of medically assisted reproduction (MAR), there is a growing emphasis on the importance of introducing new assisted reproductive technologies (ARTs) only after thorough preclinical safety research, including the use of animal models. At the same time, there is international support for the three R's (replace, reduce, refine), and the European Union even aims at the full replacement of animals for research. The apparent tension between these two trends underlines the urgency of an explicit justification of the use of animals for the development and preclinical testing of new ARTs. Considering that the use of animals remains necessary for specific forms of ART research and taking account of different views on the moral importance of helping people to have a genetically related child, we argue that, in principle, the importance of safety research as part of responsible innovation outweighs the limited infringement of animal wellbeing involved in ART research.

  11. Optimization of Thixoforging Parameters for C70S6 Steel Connecting Rods

    NASA Astrophysics Data System (ADS)

    Özkara, İsa Metin; Baydoğan, Murat

    2016-11-01

    A microalloyed steel, C70S6, with a solidification interval of 1390-1479 °C, was thixoforged in the semisolid state in a closed die at temperatures in the range 1400-1475 °C to form a 1/7 scaled-down model of a passenger vehicle connecting rod. Die design and an optimized thixoforging temperature eliminated the excessive flash and other problems during forging. Tension test samples from connecting rods thixoforged at the optimum temperature of 1440 °C exhibited nearly the same hardness, yield strength, and ultimate tensile strength as conventional hot forged samples but ductility decreased by about 45% due to grain boundary ferrite network formed during cooling from the thixoforging temperature. Thus, C70S6-grade steel can be thixoforged at 1440 °C to form flash-free connecting rods. This conclusion was also validated using FEA analysis.

  12. On supersymmetric AdS6 solutions in 10 and 11 dimensions

    NASA Astrophysics Data System (ADS)

    Gutowski, J.; Papadopoulos, G.

    2017-12-01

    We prove a non-existence theorem for smooth, supersymmetric, warped AdS 6 solutions with connected, compact without boundary internal space in D = 11 and (massive) IIA supergravities. In IIB supergravity we show that if such AdS 6 solutions exist, then the NSNS and RR 3-form fluxes must be linearly independent and certain spinor bilinears must be appropriately restricted. Moreover we demonstrate that the internal space admits an so(3) action which leaves all the fields invariant and for smooth solutions the principal orbits must have co-dimension two. We also describe the topology and geometry of internal spaces that admit such a so(3) action and show that there are no solutions for which the internal space has topology F × S 2, where F is an oriented surface.

  13. S6K1ing to ResTOR Adipogenesis with Polycomb.

    PubMed

    Juan, Aster H; Sartorelli, Vittorio

    2016-05-05

    Signal-directed chromatin recruitment of mammalian Polycomb complexes is a fundamental component of epigenetic regulation. In this issue, Yi et al. (2016) reveal how mTORC1 activation deploys the ribosomal serine/threonine kinase S6K1 and Polycomb proteins at genomic regulatory regions to repress expression of anti-adipogenic developmental regulators. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Akt-RSK-S6-kinase Signaling Networks Activated by Oncogenic Receptor Tyrosine Kinases

    PubMed Central

    Moritz, Albrecht; Li, Yu; Guo, Ailan; Villén, Judit; Wang, Yi; MacNeill, Joan; Kornhauser, Jon; Sprott, Kam; Zhou, Jing; Possemato, Anthony; Ren, Jian Min; Hornbeck, Peter; Cantley, Lewis C.; Gygi, Steven P.; Rush, John; Comb, Michael J.

    2011-01-01

    Receptor tyrosine kinases (RTKs) activate pathways mediated by serine/threonine (Ser/Thr) kinases such as the PI3K (phosphatidylinositol 3-kinase)-Akt pathway, the Ras-MAPK (mitogen-activated protein kinase)-RSK pathway, and the mTOR (mammalian target of rapamycin)-p70 S6 pathway that control important aspects of cell growth, proliferation, and survival. The Akt, RSK, and p70 S6 family of protein kinases transmit signals by phosphorylating substrates on a RxRxxS/T motif. Here, we developed a large-scale proteomic approach to identify over 200 substrates of this kinase family in cancer cell lines driven by the c-Met, epidermal growth factor receptor (EGFR), or platelet-derived growth factor receptor a (PDGFRα) RTKs. We identified a subset of proteins with RxRxxS/T sites for which phosphorylation was decreased by RTKIs as well as by inhibitors of the PI3K, mTOR, and MAPK pathways and determined the effects of siRNA directed against these substrates on cell viability. We found that phosphorylation of the protein chaperone SGTA (small glutamine-rich tetratricopeptide repeat-containing protein alpha) at Ser305 is essential for PDGFRα stabilization and cell survival in PDGFRα-dependent cancer cells. Our approach provides a new view of RTK and Akt-RSK-S6 kinase signaling, revealing many previously unidentified Akt-RSK-S6 kinase substrates that merit further consideration as targets for combination therapy with RTKIs. PMID:20736484

  15. Final report of APMP.QM-S6: clenbuterol in porcine meat

    NASA Astrophysics Data System (ADS)

    Sin, D. W.-M.; Ho, C.; Yip, Y.-C.

    2016-01-01

    At the CCQM Organic Analysis Working Group (OAWG) Meeting held in April 2012 and the APMP TCQM Meeting held in November 2012, an APMP supplementary comparison (APMP.QM-S6) on the determination of clenbuterol in porcine meat was supported by the OAWG and APMP TCQM. This comparison was organized by the Government Laboratory, Hong Kong. In order to accommodate a wider participation, a pilot study (APMP.QM-P22) was run in parallel to APMP.QM-S6. This study provided the means for assessing the measurement capabilities for determination of low-polarity measurands in a procedure that requires extraction, clean-up, analytical separation, and selective detection in a food matrix. A total of 7 institutes registered for the supplementary comparison and 6 of them submitted their results. 4 results were included for SCRV calculation. All participating laboratories applied Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry (ID-LCMS/MS) technique with clenbuterol-d9 as internal standard spiked for quantitation in this programme. KEY WORDS FOR SEARCH APMP.QM-S6 and Clenbuterol Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  16. Room-Temperature Synthesis of Thiostannates from {[Ni(tren)]2[Sn2S6]}n.

    PubMed

    Hilbert, Jessica; Näther, Christian; Weihrich, Richard; Bensch, Wolfgang

    2016-08-15

    The compound {[Ni(tren)]2[Sn2S6]}n (1) (tren = tris(2-aminoethyl)amine, C6H18N4) was successfully applied as source for the room-temperature synthesis of the new thiostannates [Ni(tren)(ma)(H2O)]2[Sn2S6]·4H2O (2) (ma = methylamine, CH5N) and [Ni(tren)(1,2-dap)]2[Sn2S6]·2H2O (3) (1,2-dap = 1,2-diaminopropane, C3H10N2). The Ni-S bonds in the Ni2S2N8 bioctahedron in the structure of 1 are analyzed with density functional theory calculations demonstrating significantly differing Ni-S bond strengths. Because of this asymmetry they are easily broken in the presence of an excess of ma or 1,2-dap immediately followed by Ni-N bond formation to N donor atoms of the amine ligands thus generating [Ni(tren)(amine)](2+) complexes. The chemical reactions are fast, and compounds 2 and 3 are formed within 1 h. The synthesis concept presented here opens hitherto unknown possibilities for preparation of new thiostannates.

  17. Pseudocapacitive Sodium Storage by Ferroelectric Sn2 P2 S6 with Layered Nanostructure.

    PubMed

    Huang, Sheng; Meng, Chao; Xiao, Min; Ren, Shan; Wang, Shuanjin; Han, Dongmei; Li, Yuning; Meng, Yuezhong

    2018-04-19

    Sodium ion batteries (SIB) are considered promising alternative candidates for lithium ion batteries (LIB) because of the wide availability and low cost of sodium, therefore the development of alternative sodium storage materials with comparable performance to LIB is urgently desired. The sodium ions with larger sizes resist intercalation or alloying because of slow reaction kinetics. Most pseudocapacitive sodium storage materials are based on subtle nanomaterial engineering, which is difficult for large-scale production. Here, ferroelectric Sn 2 P 2 S 6 with layered nanostructure is developed as sodium ion storage material. The ferroelectricity-enhanced pseudocapacitance of sodium ion in the interlayer spacing makes the electrochemical reaction easier and faster, endowing the Sn 2 P 2 S 6 electrode with excellent rate capability and cycle stability. Furthermore, the facile solid state reaction synthesis and common electrode fabrication make the Sn 2 P 2 S 6 that becomes a promising anode material of SIB. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Preclinical Rheumatoid Arthritis (Autoantibodies): An Updated Review

    PubMed Central

    Deane, Kevin D.

    2014-01-01

    Multiple studies demonstrate that there is a period of development of rheumatoid arthritis (RA) during which there are elevations of disease-related biomarkers, including autoantibodies, in the absence of and prior to the development of RA; this period can be termed ‘preclinical RA’. These ‘preclinical’ autoantibodies including rheumatoid factor and antibodies to citrullinated protein antigens, and more recent studies have also identified a wider variety of autoantibodies and a wide range of inflammatory biomarkers. These findings in conjunction with established and emerging data about genetic and environmental risk factors for RA support a model of disease development where certain factors lead to an initial triggering of RA-related autoimmunity that expands over time to the point where symptomatic arthritis classifiable as RA develops. Herein will be reviewed updates in the field, as well as a discussion of current limitations of our understanding of preclinical RA, and potential future directions for study. PMID:24643396

  19. Preclinical Alzheimer's Disease: Implications for Refinement of the Concept.

    PubMed

    Vos, Stephanie J B; Visser, Pieter Jelle

    2018-05-23

    Increasing interest in clinical trials and clinical research settings to identify Alzheimer's disease (AD) in the earliest stages of the disease has led to the concept of preclinical AD. Individuals with preclinical AD have AD pathology without clinical symptoms yet. Accumulating evidence has shown that biomarkers can identify preclinical AD and that preclinical AD is associated with a poor clinical outcome. Little is known yet about the role of vascular and lifestyle risk factors in the development of preclinical AD. In order to better understand preclinical AD pathology and clinical progression rates, there is a need to refine the concept of preclinical AD. This will be of great value for advancements in future research, clinical trials, and eventually clinical practice.

  20. Differential activation of p70 and p85 S6 kinase isoforms during cardiac hypertrophy in the adult mammal.

    PubMed

    Laser, M; Kasi, V S; Hamawaki, M; Cooper, G; Kerr, C M; Kuppuswamy, D

    1998-09-18

    An adult feline right ventricular pressure overload (RVPO) model was used to examine the two S6 kinase (S6K) isoforms, p70(S6K) and p85(S6K), that are involved in translational and transcriptional activation. Biochemical and confocal microscopy analyses at the level of the cardiocyte revealed that p70(S6K) is present predominantly in the cytosol, substantially activated in 1-h RVPO (>12 fold), and phosphorylated in the pseudosubstrate domain at the Ser-411, Thr-421, and Ser-424 sites. p85(S6K), which was localized exclusively in the nucleus, showed activation subsequent to p70(S6K), with a sustained increase in phosphorylation for up to 48 h of RVPO at equivalent sites of p70(S6K), Thr-421 and Ser-424, but not at Ser-411. Neither isoform translocated between the cytosol and the nucleus. Further studies to determine potential upstream elements of S6K activation revealed: (i) similar time course of activation for protein kinase C isoforms (alpha, gamma, and epsilon) and c-Raf, (ii) absence of accompanying phosphatidylinositol 3-kinase activation, (iii) activation of c-Src subsequent to p70(S6K), and (iv) similar changes in adult cardiocytes after treatment with 12-O-tetradecanoylphorbol-13-acetate. Thus, these studies suggest that a protein kinase C-mediated pathway couples pressure overload to growth induction via differential activation of S6K isoforms in cardiac hypertrophy.

  1. Cannabidiol Counteracts Amphetamine-Induced Neuronal and Behavioral Sensitization of the Mesolimbic Dopamine Pathway through a Novel mTOR/p70S6 Kinase Signaling Pathway

    PubMed Central

    Renard, Justine; Loureiro, Michael; Rosen, Laura G.; Zunder, Jordan; de Oliveira, Cleusa; Schmid, Susanne; Rushlow, Walter J.

    2016-01-01

    Schizophrenia-related psychosis is associated with disturbances in mesolimbic dopamine (DA) transmission, characterized by hyperdopaminergic activity in the mesolimbic pathway. Currently, the only clinically effective treatment for schizophrenia involves the use of antipsychotic medications that block DA receptor transmission. However, these medications produce serious side effects leading to poor compliance and treatment outcomes. Emerging evidence points to the involvement of a specific phytochemical component of marijuana called cannabidiol (CBD), which possesses promising therapeutic properties for the treatment of schizophrenia-related psychoses. However, the neuronal and molecular mechanisms through which CBD may exert these effects are entirely unknown. We used amphetamine (AMPH)-induced sensitization and sensorimotor gating in rats, two preclinical procedures relevant to schizophrenia-related psychopathology, combined with in vivo single-unit neuronal electrophysiology recordings in the ventral tegmental area, and molecular analyses to characterize the actions of CBD directly in the nucleus accumbens shell (NASh), a brain region that is the current target of most effective antipsychotics. We demonstrate that Intra-NASh CBD attenuates AMPH-induced sensitization, both in terms of DAergic neuronal activity measured in the ventral tegmental area and psychotomimetic behavioral analyses. We further report that CBD controls downstream phosphorylation of the mTOR/p70S6 kinase signaling pathways directly within the NASh. Our findings demonstrate a novel mechanism for the putative antipsychotic-like properties of CBD in the mesolimbic circuitry. We identify the molecular signaling pathways through which CBD may functionally reduce schizophrenia-like neuropsychopathology. SIGNIFICANCE STATEMENT The cannabis-derived phytochemical, cannabidiol (CBD), has been shown to have pharmacotherapeutic efficacy for the treatment of schizophrenia. However, the mechanisms by which

  2. Cannabidiol Counteracts Amphetamine-Induced Neuronal and Behavioral Sensitization of the Mesolimbic Dopamine Pathway through a Novel mTOR/p70S6 Kinase Signaling Pathway.

    PubMed

    Renard, Justine; Loureiro, Michael; Rosen, Laura G; Zunder, Jordan; de Oliveira, Cleusa; Schmid, Susanne; Rushlow, Walter J; Laviolette, Steven R

    2016-05-04

    Schizophrenia-related psychosis is associated with disturbances in mesolimbic dopamine (DA) transmission, characterized by hyperdopaminergic activity in the mesolimbic pathway. Currently, the only clinically effective treatment for schizophrenia involves the use of antipsychotic medications that block DA receptor transmission. However, these medications produce serious side effects leading to poor compliance and treatment outcomes. Emerging evidence points to the involvement of a specific phytochemical component of marijuana called cannabidiol (CBD), which possesses promising therapeutic properties for the treatment of schizophrenia-related psychoses. However, the neuronal and molecular mechanisms through which CBD may exert these effects are entirely unknown. We used amphetamine (AMPH)-induced sensitization and sensorimotor gating in rats, two preclinical procedures relevant to schizophrenia-related psychopathology, combined with in vivo single-unit neuronal electrophysiology recordings in the ventral tegmental area, and molecular analyses to characterize the actions of CBD directly in the nucleus accumbens shell (NASh), a brain region that is the current target of most effective antipsychotics. We demonstrate that Intra-NASh CBD attenuates AMPH-induced sensitization, both in terms of DAergic neuronal activity measured in the ventral tegmental area and psychotomimetic behavioral analyses. We further report that CBD controls downstream phosphorylation of the mTOR/p70S6 kinase signaling pathways directly within the NASh. Our findings demonstrate a novel mechanism for the putative antipsychotic-like properties of CBD in the mesolimbic circuitry. We identify the molecular signaling pathways through which CBD may functionally reduce schizophrenia-like neuropsychopathology. The cannabis-derived phytochemical, cannabidiol (CBD), has been shown to have pharmacotherapeutic efficacy for the treatment of schizophrenia. However, the mechanisms by which CBD may produce

  3. Ensuring transparency and minimization of methodologic bias in preclinical pain research: PPRECISE considerations.

    PubMed

    Andrews, Nick A; Latrémolière, Alban; Basbaum, Allan I; Mogil, Jeffrey S; Porreca, Frank; Rice, Andrew S C; Woolf, Clifford J; Currie, Gillian L; Dworkin, Robert H; Eisenach, James C; Evans, Scott; Gewandter, Jennifer S; Gover, Tony D; Handwerker, Hermann; Huang, Wenlong; Iyengar, Smriti; Jensen, Mark P; Kennedy, Jeffrey D; Lee, Nancy; Levine, Jon; Lidster, Katie; Machin, Ian; McDermott, Michael P; McMahon, Stephen B; Price, Theodore J; Ross, Sarah E; Scherrer, Grégory; Seal, Rebecca P; Sena, Emily S; Silva, Elizabeth; Stone, Laura; Svensson, Camilla I; Turk, Dennis C; Whiteside, Garth

    2016-04-01

    There is growing concern about lack of scientific rigor and transparent reporting across many preclinical fields of biological research. Poor experimental design and lack of transparent reporting can result in conscious or unconscious experimental bias, producing results that are not replicable. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the U.S. Food and Drug Administration sponsored a consensus meeting of the Preclinical Pain Research Consortium for Investigating Safety and Efficacy (PPRECISE) Working Group. International participants from universities, funding agencies, government agencies, industry, and a patient advocacy organization attended. Reduction of publication bias, increasing the ability of others to faithfully repeat experimental methods, and increased transparency of data reporting were specifically discussed. Parameters deemed essential to increase confidence in the published literature were clear, specific reporting of an a priori hypothesis and definition of primary outcome measure. Power calculations and whether measurement of minimal meaningful effect size to determine these should be a core component of the preclinical research effort provoked considerable discussion, with many but not all agreeing. Greater transparency of reporting should be driven by scientists, journal editors, reviewers, and grant funders. The conduct of high-quality science that is fully reported should not preclude novelty and innovation in preclinical pain research, and indeed, any efforts that curtail such innovation would be misguided. We believe that to achieve the goal of finding effective new treatments for patients with pain, the pain field needs to deal with these challenging issues.

  4. Ensuring transparency and minimization of methodologic bias in preclinical pain research: PPRECISE considerations

    PubMed Central

    Andrews, Nick A.; Latrémolière, Alban; Basbaum, Allan I.; Mogil, Jeffrey S.; Porreca, Frank; Rice, Andrew S.C.; Woolf, Clifford J.; Currie, Gillian L.; Dworkin, Robert H.; Eisenach, James C.; Evans, Scott; Gewandter, Jennifer S.; Gover, Tony D.; Handwerker, Hermann; Huang, Wenlong; Iyengar, Smriti; Jensen, Mark P.; Kennedy, Jeffrey D.; Lee, Nancy; Levine, Jon; Lidster, Katie; Machin, Ian; McDermott, Michael P.; McMahon, Stephen B.; Price, Theodore J.; Ross, Sarah E.; Scherrer, Grégory; Seal, Rebecca P.; Sena, Emily S.; Silva, Elizabeth; Stone, Laura; Svensson, Camilla I.; Turk, Dennis C.; Whiteside, Garth

    2015-01-01

    Abstract There is growing concern about lack of scientific rigor and transparent reporting across many preclinical fields of biological research. Poor experimental design and lack of transparent reporting can result in conscious or unconscious experimental bias, producing results that are not replicable. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public–private partnership with the U.S. Food and Drug Administration sponsored a consensus meeting of the Preclinical Pain Research Consortium for Investigating Safety and Efficacy (PPRECISE) Working Group. International participants from universities, funding agencies, government agencies, industry, and a patient advocacy organization attended. Reduction of publication bias, increasing the ability of others to faithfully repeat experimental methods, and increased transparency of data reporting were specifically discussed. Parameters deemed essential to increase confidence in the published literature were clear, specific reporting of an a priori hypothesis and definition of primary outcome measure. Power calculations and whether measurement of minimal meaningful effect size to determine these should be a core component of the preclinical research effort provoked considerable discussion, with many but not all agreeing. Greater transparency of reporting should be driven by scientists, journal editors, reviewers, and grant funders. The conduct of high-quality science that is fully reported should not preclude novelty and innovation in preclinical pain research, and indeed, any efforts that curtail such innovation would be misguided. We believe that to achieve the goal of finding effective new treatments for patients with pain, the pain field needs to deal with these challenging issues. PMID:26683237

  5. Modeling the Western Diet for Preclinical Investigations.

    PubMed

    Hintze, Korry J; Benninghoff, Abby D; Cho, Clara E; Ward, Robert E

    2018-05-01

    Rodent models have been invaluable for biomedical research. Preclinical investigations with rodents allow researchers to investigate diseases by using study designs that are not suitable for human subjects. The primary criticism of preclinical animal models is that results are not always translatable to humans. Some of this lack of translation is due to inherent differences between species. However, rodent models have been refined over time, and translatability to humans has improved. Transgenic animals have greatly aided our understanding of interactions between genes and disease and have narrowed the translation gap between humans and model animals. Despite the technological innovations of animal models through advances in genetics, relatively little attention has been given to animal diets. Namely, developing diets that replicate what humans eat will help make animal models more relevant to human populations. This review focuses on commonly used rodent diets that are used to emulate the Western dietary pattern in preclinical studies of obesity and type 2 diabetes, nonalcoholic liver disease, maternal nutrition, and colorectal cancer.

  6. Reduced Ribosomal Protein S6 Phosphorylation following Progressive Resistance Exercise in Growing Adolescent Rats

    PubMed Central

    Hellyer, Nathan J.; Nokleby, Jessica J.; Thicke, Bethany M.; Zhan, Wen-Zhi; Sieck, Gary C.; Mantilla, Carlos B.

    2011-01-01

    The purpose of the present study was to investigate moderate intensity progressive resistance exercise (PRE) in growing adolescent rats and its effect on muscle hypertrophy (defined as an increase in fiber cross-sectional area). We hypothesized that in adolescent animals moderate intensity PRE would increase: 1) fiber cross-sectional area (CSA); 2) myosin heavy chain (MyHC) content; and 3) expression and phosphorylation of cell signaling molecules involved in translational regulation, compared to age-matched sedentary controls (SED). In the PRE group, three-week old male rats were trained to climb a vertical ladder as a mode of PRE training such that by 10 weeks, all animals in the PRE group had progressed to carry an additional 80% of body weight per climb. In agreement with our hypotheses, we observed that 10 weeks of moderate PRE in adolescent animals was sufficient to increase CSA of muscle fibers and increase MyHC content. Average muscle fiber CSA increased by greater than 10% and total MyHC content increased by 35% (p<0.05) in the PRE group compared to SED animals. Concurrently, we investigated sustained changes in the expression and phosphorylation of key signaling molecules that are previously identified regulators of hypertrophy in adult animal models. Contrary to our hypotheses, expression and phosphorylation of the translational regulators mTOR and Akt were not increased in the PRE group. In addition, we observed that the ratio of phosphorylated-to-unphosphorylated ribosomal protein S6 (rpS6) was reduced over six-fold in PRE animals (p<0.05) and total rpS6 protein levels were unchanged between PRE and sedentary animals (p>0.05). We conclude that moderate intensity PRE is sufficient to induce muscle hypertrophy in adolescent animals while the signaling mechanisms associated with muscle hypertrophy may differ between growing adolescents and adults. PMID:22614147

  7. Cardiovascular effects of two disulfide analogues of sarafotoxin S6b.

    PubMed

    Lin, W W; Chen, Y M; Lee, S Y; Nishio, H; Kimura, T; Sakakibara, S; Lee, C Y

    1990-01-01

    Sarafotoxin S6b (STX-b), a peptide toxin isolated from the venom of the Israeli burrowing asp, Atractaspis engaddensis, consists of 21 amino acid residues with four cysteines at positions 1,3,11 and 15. In the present study, we compared the cardiovascular effects of two synthetic STX-b analogues with different disulfide bridge locations, i.e. STX-b type A (1-15, 3-11) and STX-b type B (1-11, 3-15). At doses of 0.3-3 nmoles/kg (i.v.), type A produced a sustained pressor effect with transient increase in pulse pressure. However, at 5 nmoles/kg, it produced a transient increase followed by decrease in blood pressure, heart rate and respiratory rate within 30 sec and 12 out of 13 mice died within 10 min. Various kinds of ECG changes, suggestive of myocardial ischemia and hyperkalemia, were observed. Type A also caused a significant increase in the plasma levels of K+, lactate dehydrogenase, creatine phosphokinase, inorganic phosphate and glucose. By contrast, type B did not kill any mouse at doses up to 50 nmoles/kg. In the rat aorta, type A caused a potent vasoconstriction which was dependent on extracellular Ca2+ and was partially inhibited by verapamil and H-7, a protein kinase C inhibitor. In the rat Langendorff heart preparation, type A produced coronary vasospasm with potency about 100 times higher than that of type B. A similar potency ratio was observed for the positive inotropic effect in rat atria. These results indicate that the location of disulfide bridges in sarafotoxin S6b markedly influences the pharmacological potency and the natural sarafotoxin S6b should be type A with the disulfide bridge locations at positions 1-15 and 3-11.

  8. Acoustic and elastic properties of Sn(2)P(2)S(6) crystals.

    PubMed

    Mys, O; Martynyuk-Lototska, I; Grabar, A; Vlokh, R

    2009-07-01

    We present the results concerned with acoustic and elastic properties of Sn(2)P(2)S(6) crystals. The complete matrices of elastic stiffness and compliance coefficients are determined in both the crystallographic coordinate system and the system associated with eigenvectors of the elastic stiffness tensor. The acoustic slowness surfaces are constructed and the propagation and polarization directions of the slowest acoustic waves promising for acousto-optic interactions are determined on this basis. The acoustic obliquity angle and the deviation of polarization of the acoustic waves from purely transverse or longitudinal states are quantitatively analysed.

  9. STS-119 Extravehicular Activity (EVA) 1 S6 Truss Umbilical Mate OPS

    NASA Image and Video Library

    2009-03-19

    S119-E-006674 (19 March 2009) --- Astronaut Steve Swanson (center), STS-119 mission specialist, participates in the mission's first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, seven-minute spacewalk, Swanson and astronaut Richard Arnold (out of frame), mission specialist, connected bolts to permanently attach the S6 truss segment to S5. The spacewalkers plugged in power and data connectors to the truss, prepared a radiator to cool it, opened boxes containing the new solar arrays and deployed the Beta Gimbal Assemblies containing masts that support the solar arrays.

  10. STS-119 Extravehicular Activity (EVA) 1 S6 Truss Umbilical Mate OPS

    NASA Image and Video Library

    2009-03-19

    S119-E-006675 (19 March 2009) --- Astronaut Steve Swanson (center right), STS-119 mission specialist, participates in the mission's first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, seven-minute spacewalk, Swanson and astronaut Richard Arnold (out of frame), mission specialist, connected bolts to permanently attach the S6 truss segment to S5. The spacewalkers plugged in power and data connectors to the truss, prepared a radiator to cool it, opened boxes containing the new solar arrays and deployed the Beta Gimbal Assemblies containing masts that support the solar arrays.

  11. STS-119 Extravehicular Activity (EVA) 1 S6 Truss Umbilical Mate OPS

    NASA Image and Video Library

    2009-03-19

    S119-E-006673 (19 March 2009) --- Astronauts Steve Swanson (center) and Richard Arnold (partially obscured above Swanson), both STS-119 mission specialists, participate in the mission's first scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, seven-minute spacewalk, Swanson and Arnold connected bolts to permanently attach the S6 truss segment to S5. The spacewalkers plugged in power and data connectors to the truss, prepared a radiator to cool it, opened boxes containing the new solar arrays and deployed the Beta Gimbal Assemblies containing masts that support the solar arrays.

  12. On temporal dynamics of Sn2P2S6 oscillation in semi-linear cavity.

    PubMed

    Arciszewski, D; Shumelyuk, A; Odoulov, S

    2013-06-01

    Experimental measurements and calculations revealed an unusual type of oscillation dynamics of Sn(2)P(2)S(6) in the semi-linear cavity. It consists of a pronounced saw-tooth modulation of oscillation intensity--although it is not 100% in contrast--with the cw component being shifted in frequency with respect to the pump wave. This effect is attributed to the hybrid mode of two semi-linear oscillation geometries, one with a single pump wave and the other with two counterpropagating pump waves.

  13. (S)-[6]-Gingerol enhances glucose uptake in L6 myotubes by activation of AMPK in response to [Ca2+]i.

    PubMed

    Li, Yiming; Tran, Van H; Koolaji, Nooshin; Duke, Colin; Roufogalis, Basil D

    2013-01-01

    The aim of this study was to investigate the mechanism of (S)-[6]-gingerol in promoting glucose uptake in L6 skeletal muscle cells. The effect of (S)-[6]-gingerol on glucose uptake in L6 myotubes was examined using 2-[1,2-3H]-deoxy-D-glucose. Intracellular Ca2+ concentration was measured using Fluo-4. Phosphorylation of AMPKα was determined by Western blotting analysis. (S)-[6]-Gingerol time-dependently enhanced glucose uptake in L6 myotubes. (S)-[6]-Gingerol elevated intracellular Ca2+ concentration and subsequently induced a dose- and time-dependent enhancement of threonine172 phosphorylated AMPKα in L6 myotubes via modulation by Ca2+/calmodulin-dependent protein kinase kinase. The results indicated that (S)-[6]-gingerol increased glucose uptake in L6 skeletal muscle cells by activating AMPK. (S)-[6]-gingerol, a major component of Zingiber officinale, may have potential for development as an antidiabetic agent.

  14. Folding behavior of ribosomal protein S6 studied by modified Go¯ -like model

    NASA Astrophysics Data System (ADS)

    Wu, L.; Zhang, J.; Wang, J.; Li, W. F.; Wang, W.

    2007-03-01

    Recent experimental and theoretical studies suggest that, although topology is the determinant factor in protein folding, especially for small single-domain proteins, energetic factors also play an important role in the folding process. The ribosomal protein S6 has been subjected to intensive studies. A radical change of the transition state in its circular permutants has been observed, which is believed to be caused by a biased distribution of contact energies. Since the simplistic topology-only Gō -like model is not able to reproduce such an observation, we modify the model by introducing variable contact energies between residues based on their physicochemical properties. The modified Gō -like model can successfully reproduce the Φ -value distributions, folding nucleus, and folding pathways of both the wild-type and circular permutants of S6. Furthermore, by comparing the results of the modified and the simplistic models, we find that the hydrophobic effect constructs the major force that balances the loop entropies. This may indicate that nature maintains the folding cooperativity of this protein by carefully arranging the location of hydrophobic residues in the sequence. Our study reveals a strategy or mechanism used by nature to get out of the dilemma when the native structure, possibly required by biological function, conflicts with folding cooperativity. Finally, the possible relationship between such a design of nature and amyloidosis is also discussed.

  15. Glutamine promotes ovarian cancer cell proliferation through the mTOR/S6 pathway

    PubMed Central

    Yuan, Lingqin; Sheng, Xiugui; Willson, Adam K; Roque, Dario R; Stine, Jessica E; Guo, Hui; Jones, Hannah M; Zhou, Chunxiao; Bae-Jump, Victoria L

    2015-01-01

    Glutamine is one of the main nutrients used by tumor cells for biosynthesis. Therefore, targeted inhibition of glutamine metabolism may have anti-tumorigenic implications. In the present study, we aimed to evaluate the effects of glutamine on ovarian cancer cell growth. Three ovarian cancer cell lines, HEY, SKOV3, and IGROV-1, were assayed for glutamine dependence by analyzing cytotoxicity, cell cycle progression, apoptosis, cell stress, and glucose/glutamine metabolism. Our results revealed that administration of glutamine increased cell proliferation in all three ovarian cancer cell lines in a dose dependent manner. Depletion of glutamine induced reactive oxygen species and expression of endoplasmic reticulum stress proteins. In addition, glutamine increased the activity of glutaminase (GLS) and glutamate dehydrogenase (GDH) by modulating the mTOR/S6 and MAPK pathways. Inhibition of mTOR activity by rapamycin or blocking S6 expression by siRNA inhibited GDH and GLS activity, leading to a decrease in glutamine-induced cell proliferation. These studies suggest that targeting glutamine metabolism may be a promising therapeutic strategy in the treatment of ovarian cancer. PMID:26045471

  16. S6 Kinase Inhibits Intrinsic Axon Regeneration Capacity via AMP Kinase in Caenorhabditis elegans

    PubMed Central

    Hubert, Thomas; Wu, Zilu; Chisholm, Andrew D.

    2014-01-01

    The ability of axons to regrow after injury is determined by the complex interplay of intrinsic growth programs and external cues. In Caenorhabditis elegans mechanosensory neuron, axons exhibit robust regenerative regrowth following laser axotomy. By surveying conserved metabolic signaling pathways, we have identified the ribosomal S6 kinase RSKS-1 as a new cell-autonomous inhibitor of axon regeneration. RSKS-1 is not required for axonal development but inhibits axon regrowth after injury in multiple neuron types. Loss of function in rsks-1 results in more rapid growth cone formation after injury and accelerates subsequent axon extension. The enhanced regrowth of rsks-1 mutants is partly dependent on the DLK-1 MAPK cascade. An essential output of RSKS-1 in axon regrowth is the metabolic sensor AMP kinase, AAK-2. We further show that the antidiabetic drug phenformin, which activates AMP kinase, can promote axon regrowth. Our data reveal a new function for an S6 kinase acting through an AMP kinase in regenerative growth of injured axons. PMID:24431434

  17. p70 ribosomal S6 kinase regulates subpleural fibrosis following transforming growth factor-α expression in the lung

    PubMed Central

    Madala, Satish K.; Thomas, George; Edukulla, Ramakrishna; Davidson, Cynthia; Schmidt, Stephanie; Schehr, Angelica

    2015-01-01

    The p70 ribosomal S6 kinase (S6K) is a downstream substrate that is phosphorylated and activated by the mammalian target of rapamycin complex and regulates multiple cellular processes associated with fibrogenesis. Recent studies demonstrate that aberrant mTORC1-S6K signaling contributes to various pathological conditions, but a direct role in pulmonary fibroproliferation has not been established. Increased phosphorylation of the S6K pathway is detected immediately following transforming growth factor-α (TGF-α) expression in a transgenic model of progressive lung fibrosis. To test the hypothesis that the S6K directly regulates pulmonary fibroproliferative disease we determined the cellular sites of S6K phosphorylation during the induction of fibrosis in the TGF-α model and tested the efficacy of specific pharmacological inhibition of the S6K pathway to prevent and reverse fibrotic disease. Following TGF-α expression increased phosphorylation of the S6K was detected in the airway and alveolar epithelium and the mesenchyme of advanced subpleural fibrotic regions. Specific inhibition of the S6K with the small molecule inhibitor LY-2584702 decreased TGF-α and platelet-derived growth factor-β-induced proliferation of lung fibroblasts in vitro. Administration of S6K inhibitors to TGF-α mice prevented the development of extensive subpleural fibrosis and alterations in lung mechanics, and attenuated the increase in total lung hydroxyproline. S6K inhibition after fibrosis was established attenuated the progression of subpleural fibrosis. Together these studies demonstrate targeting the S6K pathway selectively modifies the progression of pulmonary fibrosis in the subpleural compartment of the lung. PMID:26566903

  18. Wilderness medicine race for preclinical students.

    PubMed

    Feazel, Leah; Block, Jason; Jayawardena, Asitha; Wehr, Peter; House, Hans; Buresh, Christopher

    2016-08-01

    Introducing medical students to wilderness medicine provides skills in leadership, teamwork, improvisation, and managing medical emergencies; however, wilderness medicine (WM) education is typically reserved for senior medical students and often requires expensive travel. Here, we describe the Winter Wilderness Medicine Race (WWMR). The race was held at a large allopathic medical school and targeted towards preclinical medical students. Race planning was performed by senior medical students with the supervision of doctors from the Department of Emergency Medicine. We hypothesized that this intervention in medical education would enhance students' WM knowledge, and build teamwork and improvisational skills. The research involved a one day WM race that required teams of first- and second-year medical students to navigate a 5-km course and complete medical scenarios. Races that were held annually between 2011 and 2014 are included in the study. The educational effectiveness of the race was evaluated by pre- and post-race knowledge assessments of the medical students participating in a WWMR. Qualitative data regarding student perceptions of the skills learned were obtained by focus group interviews. Wilderness medicine provides skills in leadership, teamwork, improvisation and managing medical emergencies Between 2011 and 2014, 122 preclinical medical students from a Midwestern US allopathic medical school participated in the study. Overall, the mean scores for pre- and post-race knowledge assessments were 48 and 85 per cent, respectively, a 37 per cent increase in scores (p < 0.0001). Participants cited improvisational and communication skills as the most important educational feature of the race. The Winter Wilderness Medicine Race (WWMR) enhanced preclinical medical students' wilderness medicine knowledge, teamwork skills and improvisational abilities. © 2015 John Wiley & Sons Ltd.

  19. Ribosomal Protein S6 Phosphorylation Is Involved in Novelty-Induced Locomotion, Synaptic Plasticity and mRNA Translation

    PubMed Central

    Puighermanal, Emma; Biever, Anne; Pascoli, Vincent; Melser, Su; Pratlong, Marine; Cutando, Laura; Rialle, Stephanie; Severac, Dany; Boubaker-Vitre, Jihane; Meyuhas, Oded; Marsicano, Giovanni; Lüscher, Christian; Valjent, Emmanuel

    2017-01-01

    The phosphorylation of the ribosomal protein S6 (rpS6) is widely used to track neuronal activity. Although it is generally assumed that rpS6 phosphorylation has a stimulatory effect on global protein synthesis in neurons, its exact biological function remains unknown. By using a phospho-deficient rpS6 knockin mouse model, we directly tested the role of phospho-rpS6 in mRNA translation, plasticity and behavior. The analysis of multiple brain areas shows for the first time that, in neurons, phospho-rpS6 is dispensable for overall protein synthesis. Instead, we found that phospho-rpS6 controls the translation of a subset of mRNAs in a specific brain region, the nucleus accumbens (Acb), but not in the dorsal striatum. We further show that rpS6 phospho-mutant mice display altered long-term potentiation (LTP) in the Acb and enhanced novelty-induced locomotion. Collectively, our findings suggest a previously unappreciated role of phospho-rpS6 in the physiology of the Acb, through the translation of a selective subclass of mRNAs, rather than the regulation of general protein synthesis. PMID:29311811

  20. (S)-[6]-Gingerol inhibits TGF-β-stimulated biglycan synthesis but not glycosaminoglycan hyperelongation in human vascular smooth muscle cells.

    PubMed

    Kamato, Danielle; Babaahmadi Rezaei, Hossein; Getachew, Robel; Thach, Lyna; Guidone, Daniel; Osman, Narin; Roufogalis, Basil; Duke, Colin C; Tran, Van Hoan; Zheng, Wenhua; Little, Peter J

    2013-07-01

    (S)-[6]-Gingerol is under investigation for a variety of therapeutic uses. Transforming growth factor (TGF)-β stimulates proteoglycan synthesis, leading to increased binding of low-density lipoproteins, which is the initiating step in atherosclerosis. We evaluated the effects of (S)-[6]-gingerol on these TGF-β-mediated proteoglycan changes to explore its potential as an anti-atherosclerotic agent. Purified (S)-[6]-gingerol was assessed for its effects on proteoglycan synthesis by [(35) S]-sulfate incorporation into glycosaminoglycan chains and [(35) S]-Met/Cys incorporation into proteoglycans and total proteins in human vascular smooth muscle cells. Biglycan level was assessed by real-time quantitative polymerase chain reactions and the effects of (S)-[6]-gingerol on TGF-β signalling by assessment of the phosphorylation of Smads and Akt by western blotting. (S)-[6]-Gingerol concentration-dependently inhibited TGF-β-stimulated proteoglycan core protein synthesis, and this was not secondary to inhibition of total protein synthesis. (S)-[6]-Gingerol inhibited biglycan mRNA expression. (S)-[6]-Gingerol did not inhibit TGF-β-stimulated glycosaminoglycan hyperelongation or phosphorylation of Smad 2, in either the carboxy terminal or linker region, or Akt phosphorylation. The activity of (S)-[6]-gingerol to inhibit TGF-β-stimulated biglycan synthesis suggests a potential role for ginger in the prevention of atherosclerosis or other lipid-binding diseases. The signalling studies indicate a novel site of action of (S)-[6]-gingerol in inhibiting TGF-β responses. © 2013 Royal Pharmaceutical Society.

  1. Ibandronate treatment for osteoporosis: rationale, preclinical, and clinical development of extended dosing regimens.

    PubMed

    Epstein, Solomon

    2006-03-01

    Ibandronate is a potent nitrogen-containing bisphosphonate available as a once-monthly oral formulation for the treatment and prevention of osteoporosis. Preclinical experiments with estrogen-depleted rats, dogs, and monkeys demonstrated the efficacy of daily and intermittent ibandronate dosing. Initial clinical trials explored the optimal dosing regimens for oral administration in humans. The Oral Ibandronate Osteoporosis Vertebral Fracture Trial in North America and Europe (BONE) and Monthly Oral Ibandronate in Ladies (MOBILE) trials demonstrated that long-term daily and intermittent administration of ibandronate was efficacious for increasing bone mineral density, reducing markers of bone turnover, and preventing fractures, while maintaining bone quality. These preclinical and clinical ibandronate trials provided progressive evidence that a simple, long interval dosing regimen could offer efficacy and safety comparable with currently available bisphosphonates. It is anticipated that once-monthly ibandronate may have a positive impact on patient adherence, and ultimately, on fracture protection in osteoporotic women.

  2. Nanoparticles in targeted cancer therapy: mesoporous silica nanoparticles entering preclinical development stage.

    PubMed

    Rosenholm, Jessica M; Mamaeva, Veronika; Sahlgren, Cecilia; Lindén, Mika

    2012-01-01

    Nanotechnology may help overcome persisting limitations of current cancer treatment and thus contribute to the creation of more effective, safer and more affordable therapies. While some nanotechnology-based drug delivery systems are already being marketed and others are in clinical trial, most still remain in the preclinical development stage. Mesoporous silica nanoparticles have been highlighted as an interesting drug delivery platform, due to their flexibility and high drug load potential. Although numerous reports demonstrate sophisticated drug delivery mechanisms in vitro, the therapeutic benefit of these systems for in vivo applications have been under continuous debate. This has been due to nontranslatable conditions used in the in vitro studies, as well as contradictory conclusions drawn from preclinical (in vivo) studies. However, recent studies have indicated that the encouraging cellular studies could in fact be repeated also in vivo. Here, we report on these recent advances regarding therapeutic efficacy, targeting and safety issues related to the application of mesoporous silica nanoparticles in cancer therapy.

  3. Adapting Preclinical Benchmarks for First-in-Human Trials of Human Embryonic Stem Cell-Based Therapies.

    PubMed

    Barazzetti, Gaia; Hurst, Samia A; Mauron, Alexandre

    2016-08-01

    : As research on human embryonic stem cell (hESC)-based therapies is moving from the laboratory to the clinic, there is an urgent need to assess when it can be ethically justified to make the step from preclinical studies to the first protocols involving human subjects. We examined existing regulatory frameworks stating preclinical requirements relevant to the move to first-in-human (FIH) trials and assessed how they may be applied in the context of hESC-based interventions to best protect research participants. Our findings show that some preclinical benchmarks require rethinking (i.e., identity, purity), while others need to be specified (i.e., potency, viability), owing to the distinctive dynamic heterogeneity of hESC-based products, which increases uncertainty and persistence of safety risks and allows for limited predictions of effects in vivo. Rethinking or adaptation of how to apply preclinical benchmarks in specific cases will be required repeatedly for different hESC-based products. This process would benefit from mutual learning if researchers included these components in the description of their methods in publications. To design translational research with an eye to protecting human participants in early trials, researchers and regulators need to start their efforts at the preclinical stage. Existing regulatory frameworks for preclinical research, however, are not really adapted to this in the case of stem cell translational medicine. This article reviews existing regulatory frameworks for preclinical requirements and assesses how their underlying principles may best be applied in the context of human embryonic stem cell-based interventions for the therapy of Parkinson's disease. This research will help to address the question of when it is ethically justified to start first-in-human trials in stem cell translational medicine. ©AlphaMed Press.

  4. Preclinical Alzheimer's disease and longitudinal driving decline.

    PubMed

    Roe, Catherine M; Babulal, Ganesh M; Head, Denise M; Stout, Sarah H; Vernon, Elizabeth K; Ghoshal, Nupur; Garland, Brad; Barco, Peggy P; Williams, Monique M; Johnson, Ann; Fierberg, Rebecca; Fague, M Scot; Xiong, Chengjie; Mormino, Elizabeth; Grant, Elizabeth A; Holtzman, David M; Benzinger, Tammie L S; Fagan, Anne M; Ott, Brian R; Carr, David B; Morris, John C

    2017-01-01

    Links between preclinical AD and driving difficulty onset would support the use of driving performance as an outcome in primary and secondary prevention trials among older adults (OAs). We examined whether AD biomarkers predicted the onset of driving difficulties among OAs. 104 OAs (65+ years) with normal cognition took part in biomarker measurements, a road test, clinical and psychometric batteries and self-reported their driving habits. Higher values of CSF tau/Aβ 42 and ptau 181 /Aβ 42 ratios, but not uptake on PIB amyloid imaging (p=.12), predicted time to a rating of Marginal or Fail on the driving test using Cox proportional hazards models. Hazards ratios (95% confidence interval) were 5.75 (1.70-19.53), p=.005 for CSF tau/Aβ 42 ; 6.19 (1.75-21.88) and p=.005 for CSF ptau 181 /Aβ 42 . Preclinical AD predicted time to receiving a Marginal or Fail rating on an on-road driving test. Driving performance shows promise as a functional outcome in AD prevention trials.

  5. Micro-ultrasound for preclinical imaging

    PubMed Central

    Foster, F. Stuart; Hossack, John; Adamson, S. Lee

    2011-01-01

    Over the past decade, non-invasive preclinical imaging has emerged as an important tool to facilitate biomedical discovery. Not only have the markets for these tools accelerated, but the numbers of peer-reviewed papers in which imaging end points and biomarkers have been used have grown dramatically. High frequency ‘micro-ultrasound’ has steadily evolved in the post-genomic era as a rapid, comparatively inexpensive imaging tool for studying normal development and models of human disease in small animals. One of the fundamental barriers to this development was the technological hurdle associated with high-frequency array transducers. Recently, new approaches have enabled the upper limits of linear and phased arrays to be pushed from about 20 to over 50 MHz enabling a broad range of new applications. The innovations leading to the new transducer technology and scanner architecture are reviewed. Applications of preclinical micro-ultrasound are explored for developmental biology, cancer, and cardiovascular disease. With respect to the future, the latest developments in high-frequency ultrasound imaging are described. PMID:22866232

  6. Fibrillar amyloid correlates of preclinical cognitive decline.

    PubMed

    Stonnington, Cynthia M; Chen, Kewei; Lee, Wendy; Locke, Dona E C; Dueck, Amylou C; Liu, Xiaofen; Roontiva, Auttawut; Fleisher, Adam S; Caselli, Richard J; Reiman, Eric M

    2014-01-01

    It is not known whether preclinical cognitive decline is associated with fibrillar β-amyloid (Aβ) deposition irrespective of apolipoprotein E (APOE) ε4 status. From a prospective observational study of 623 cognitively normal individuals, we identified all subjects who showed preclinical decline of at least 2 standard deviations beyond the decline of the entire group in memory or executive function. Fourteen decliners were matched by APOE ε4 gene dose, age, sex, and education with 14 nondecliners. Dynamic Pittsburgh compound B (PiB) positron emission tomography (PET) scans, the Logan method, statistical parametric mapping, and automatically labeled regions of interest were used to characterize and compare cerebral-to-cerebellar PiB distribution volume ratios (DVRs), reflecting fibrillar Aβ burden. At P < .005 (uncorrected), decliners had significantly greater DVRs in comparison to nondecliners. Asymptomatic longitudinal neuropsychological decline is associated with subsequent increased fibrillar amyloid deposition, even when controlling for APOE ε4 genotype. Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  7. Preclinical Alzheimer disease and risk of falls.

    PubMed

    Stark, Susan L; Roe, Catherine M; Grant, Elizabeth A; Hollingsworth, Holly; Benzinger, Tammie L; Fagan, Anne M; Buckles, Virginia D; Morris, John C

    2013-07-30

    We determined the rate of falls among cognitively normal, community-dwelling older adults, some of whom had presumptive preclinical Alzheimer disease (AD) as detected by in vivo imaging of fibrillar amyloid plaques using Pittsburgh compound B (PiB) and PET and/or by assays of CSF to identify Aβ₄₂, tau, and phosphorylated tau. We conducted a 12-month prospective cohort study to examine the cumulative incidence of falls. Participants were evaluated clinically and underwent PiB PET imaging and lumbar puncture. Falls were reported monthly using an individualized calendar journal returned by mail. A Cox proportional hazards model was used to test whether time to first fall was associated with each biomarker and the ratio of CSF tau/Aβ₄₂ and CSF phosphorylated tau/Aβ₄₂, after adjustment for common fall risk factors. The sample (n = 125) was predominately female (62.4%) and white (96%) with a mean age of 74.4 years. When controlled for ability to perform activities of daily living, higher levels of PiB retention (hazard ratio = 2.95 [95% confidence interval 1.01-6.45], p = 0.05) and of CSF biomarker ratios (p < 0.001) were associated with a faster time to first fall. Presumptive preclinical AD is a risk factor for falls in older adults. This study suggests that subtle noncognitive changes that predispose older adults to falls are associated with AD and may precede detectable cognitive changes.

  8. Room-temperature ferroelectricity in CuInP 2S 6 ultrathin flakes

    DOE PAGES

    Liu, Fucai; You, Lu; Seyler, Kyle L.; ...

    2016-08-11

    In this study, two-dimensional (2D) materials have emerged as promising candidates for various optoelectronic applications based on their diverse electronic properties, ranging from insulating to superconducting. However, cooperative phenomena such as ferroelectricity in the 2D limit have not been well explored. Here, we report room-temperature ferroelectricity in 2D CuInP 2S 6 (CIPS) with a transition temperature of ~320 K. Switchable polarization is observed in thin CIPS of ~4 nm. To demonstrate the potential of this 2D ferroelectric material, we prepare a van der Waals (vdW) ferroelectric diode formed by CIPS/Si heterostructure, which shows good memory behaviour with on/off ratio ofmore » ~100. The addition of ferroelectricity to the 2D family opens up possibilities for numerous novel applications, including sensors, actuators, non-volatile memory devices, and various vdW heterostructures based on 2D ferroelectricity.« less

  9. Room-temperature ferroelectricity in CuInP2S6 ultrathin flakes

    PubMed Central

    Liu, Fucai; You, Lu; Seyler, Kyle L.; Li, Xiaobao; Yu, Peng; Lin, Junhao; Wang, Xuewen; Zhou, Jiadong; Wang, Hong; He, Haiyong; Pantelides, Sokrates T.; Zhou, Wu; Sharma, Pradeep; Xu, Xiaodong; Ajayan, Pulickel M.; Wang, Junling; Liu, Zheng

    2016-01-01

    Two-dimensional (2D) materials have emerged as promising candidates for various optoelectronic applications based on their diverse electronic properties, ranging from insulating to superconducting. However, cooperative phenomena such as ferroelectricity in the 2D limit have not been well explored. Here, we report room-temperature ferroelectricity in 2D CuInP2S6 (CIPS) with a transition temperature of ∼320 K. Switchable polarization is observed in thin CIPS of ∼4 nm. To demonstrate the potential of this 2D ferroelectric material, we prepare a van der Waals (vdW) ferroelectric diode formed by CIPS/Si heterostructure, which shows good memory behaviour with on/off ratio of ∼100. The addition of ferroelectricity to the 2D family opens up possibilities for numerous novel applications, including sensors, actuators, non-volatile memory devices, and various vdW heterostructures based on 2D ferroelectricity. PMID:27510418

  10. Room-temperature ferroelectricity in CuInP2S6 ultrathin flakes

    NASA Astrophysics Data System (ADS)

    Liu, Fucai; You, Lu; Seyler, Kyle L.; Li, Xiaobao; Yu, Peng; Lin, Junhao; Wang, Xuewen; Zhou, Jiadong; Wang, Hong; He, Haiyong; Pantelides, Sokrates T.; Zhou, Wu; Sharma, Pradeep; Xu, Xiaodong; Ajayan, Pulickel M.; Wang, Junling; Liu, Zheng

    2016-08-01

    Two-dimensional (2D) materials have emerged as promising candidates for various optoelectronic applications based on their diverse electronic properties, ranging from insulating to superconducting. However, cooperative phenomena such as ferroelectricity in the 2D limit have not been well explored. Here, we report room-temperature ferroelectricity in 2D CuInP2S6 (CIPS) with a transition temperature of ~320 K. Switchable polarization is observed in thin CIPS of ~4 nm. To demonstrate the potential of this 2D ferroelectric material, we prepare a van der Waals (vdW) ferroelectric diode formed by CIPS/Si heterostructure, which shows good memory behaviour with on/off ratio of ~100. The addition of ferroelectricity to the 2D family opens up possibilities for numerous novel applications, including sensors, actuators, non-volatile memory devices, and various vdW heterostructures based on 2D ferroelectricity.

  11. Room-temperature ferroelectricity in CuInP2S6 ultrathin flakes.

    PubMed

    Liu, Fucai; You, Lu; Seyler, Kyle L; Li, Xiaobao; Yu, Peng; Lin, Junhao; Wang, Xuewen; Zhou, Jiadong; Wang, Hong; He, Haiyong; Pantelides, Sokrates T; Zhou, Wu; Sharma, Pradeep; Xu, Xiaodong; Ajayan, Pulickel M; Wang, Junling; Liu, Zheng

    2016-08-11

    Two-dimensional (2D) materials have emerged as promising candidates for various optoelectronic applications based on their diverse electronic properties, ranging from insulating to superconducting. However, cooperative phenomena such as ferroelectricity in the 2D limit have not been well explored. Here, we report room-temperature ferroelectricity in 2D CuInP2S6 (CIPS) with a transition temperature of ∼320 K. Switchable polarization is observed in thin CIPS of ∼4 nm. To demonstrate the potential of this 2D ferroelectric material, we prepare a van der Waals (vdW) ferroelectric diode formed by CIPS/Si heterostructure, which shows good memory behaviour with on/off ratio of ∼100. The addition of ferroelectricity to the 2D family opens up possibilities for numerous novel applications, including sensors, actuators, non-volatile memory devices, and various vdW heterostructures based on 2D ferroelectricity.

  12. Optimizing ZnS/6LiF scintillators for wavelength-shifting-fiber neutron detectors

    SciTech Connect

    Crow, Lowell; Funk, Loren L; Hannan, Bruce W

    2016-01-01

    In this paper we compare the performance of grooved and flat ZnS/6LiF scintillators in a wavelength shifting-fiber (WLSF) detector. Flat ZnS/6LiF scintillators with the thickness L=0.2-0.8 mm were characterized using photon counting and pulse-height analysis and compared to a grooved scintillator of approximately 0.8 mm thick. While a grooved scintillator considerably increases the apparent thickness of the scintillator to neutrons for a given coating thickness, we find that the flat scintillators perform better than the grooved scintillators in terms of both light yield and neutron detection efficiency. The flat 0.8-mm-thick scintillator has the highest light output, and it is 52%more » higher compared with a grooved scintillator of same thickness. The lower light output of the grooved scintillator as compared to the flat scintillator is consistent with the greater scintillator-WLSF separation and the much larger average emission angle of the grooved scintillator. We also find that the average light cone width, or photon travel-length as measured using time-of-flight powder diffraction of diamond and vanadium, decreases with increasing L in the range of L=0.6-0.8 mm. This result contrasts with the traditional Swank diffusion model for micro-composite scintillators, and could be explained by a decrease in photon diffusion-coefficient or an increase in micro-particle content in the flat scintillator matrix for the thicker scintillators.« less

  13. The mTOR Substrate S6 Kinase 1 (S6K1) Is a Negative Regulator of Axon Regeneration and a Potential Drug Target for Central Nervous System Injury

    PubMed Central

    Ding, Ying; Slepak, Tatiana; Sun, Yan; Martinez, Yania; Xu, Xiao-Ming

    2017-01-01

    The mammalian target of rapamycin (mTOR) positively regulates axon growth in the mammalian central nervous system (CNS). Although axon regeneration and functional recovery from CNS injuries are typically limited, knockdown or deletion of PTEN, a negative regulator of mTOR, increases mTOR activity and induces robust axon growth and regeneration. It has been suggested that inhibition of S6 kinase 1 (S6K1, gene symbol: RPS6KB1), a prominent mTOR target, would blunt mTOR's positive effect on axon growth. In contrast to this expectation, we demonstrate that inhibition of S6K1 in CNS neurons promotes neurite outgrowth in vitro by twofold to threefold. Biochemical analysis revealed that an mTOR-dependent induction of PI3K signaling is involved in mediating this effect of S6K1 inhibition. Importantly, treating female mice in vivo with PF-4708671, a selective S6K1 inhibitor, stimulated corticospinal tract regeneration across a dorsal spinal hemisection between the cervical 5 and 6 cord segments (C5/C6), increasing axon counts for at least 3 mm beyond the injury site at 8 weeks after injury. Concomitantly, treatment with PF-4708671 produced significant locomotor recovery. Pharmacological targeting of S6K1 may therefore constitute an attractive strategy for promoting axon regeneration following CNS injury, especially given that S6K1 inhibitors are being assessed in clinical trials for nononcological indications. SIGNIFICANCE STATEMENT Despite mTOR's well-established function in promoting axon regeneration, the role of its downstream target, S6 kinase 1 (S6K1), has been unclear. We used cellular assays with primary neurons to demonstrate that S6K1 is a negative regulator of neurite outgrowth, and a spinal cord injury model to show that it is a viable pharmacological target for inducing axon regeneration. We provide mechanistic evidence that S6K1's negative feedback to PI3K signaling is involved in axon growth inhibition, and show that phosphorylation of S6K1 is a more

  14. Ribosomal protein S6 kinase1 coordinates with TOR-Raptor2 to regulate thylakoid membrane biosynthesis in rice.

    PubMed

    Sun, Linxiao; Yu, Yonghua; Hu, Weiqin; Min, Qiming; Kang, Huiling; Li, Yilu; Hong, Yue; Wang, Xuemin; Hong, Yueyun

    2016-07-01

    Ribosomal protein S6 kinase (S6K) functions as a key component in the target of rapamycin (TOR) pathway involved in multiple processes in eukaryotes. The role and regulation of TOR-S6K in lipid metabolism remained unknown in plants. Here we provide genetic and pharmacological evidence that TOR-Raptor2-S6K1 is important for thylakoid galactolipid biosynthesis and thylakoid grana modeling in rice (Oryza sativa L.). Genetic suppression of S6K1 caused pale yellow-green leaves, defective thylakoid grana architecture. S6K1 directly interacts with Raptor2, a core component in TOR signaling, and S6K1 activity is regulated by Raptor2 and TOR. Plants with suppressed Raptor2 expression or reduced TOR activity by inhibitors mimicked the S6K1-deficient phenotype. A significant reduction in galactolipid content was found in the s6k1, raptor2 mutant or TOR-inhibited plants, which was accompanied by decreased transcript levels of the set of genes such as lipid phosphate phosphatase α5 (LPPα5), MGDG synthase 1 (MGD1), and DGDG synthase 1 (DGD1) involved in galactolipid synthesis, compared to the control plants. Moreover, loss of LPPα5 exhibited a similar phenotype with pale yellow-green leaves. These results suggest that TOR-Raptor2-S6K1 is important for modulating thylakoid membrane lipid biosynthesis, homeostasis, thus enhancing thylakoid grana architecture and normal photosynthesis ability in rice. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. RGD-containing peptides activate S6K1 through beta3 integrin in adult cardiac muscle cells.

    PubMed

    Balasubramanian, Sundaravadivel; Kuppuswamy, Dhandapani

    2003-10-24

    The enzyme p70S6 kinase (S6K1) is critical for cell growth, and we have reported its activation during cardiac hypertrophy. Because cardiac hypertrophy also involves integrin activation, we analyzed whether integrins could contribute to S6K1 activation. Using adult feline cardiomyocytes, here we report that integrin-interacting Arg-Gly-Asp (RGD) peptides activate S6K1 as observed by band shifting, kinase activity and phosphorylation at Thr-389 and Thr-421/Ser-424 of S6K1, and S6 protein phosphorylation. Perturbation of specific integrin function with blocking antibodies and by overexpressing the beta1A cytoplasmic tail revealed that beta3 but not beta1 integrin mediates the RGD-induced S6K1 activation. This activation is focal adhesion complex-independent and is accompanied by the activation of extracellular signal-regulated kinases 1/2 (ERK) and mammalian target of rapamycin (mTOR). Studies using specific inhibitors and dominant negative c-Raf expression in cardiomyocytes indicate that the S6K1 activation involves mTOR, MEK/ERK, and phosphatidylinositol 3-kinase pathways and is independent of protein kinase C and c-Raf. Finally, addition of fluorescent-labeled RGD peptide to cardiomyocytes exhibits its internalization and localization to the endocytic vesicles, and pretreatment of cardiomyocytes with endocytic inhibitors reduced the S6K1 activation. These data suggest that RGD interaction with beta3 integrin and its subsequent endocytosis trigger specific signaling pathway(s) for S6K1 activation in cardiomyocytes and that this process may contribute to hypertrophic growth and remodeling of myocardium.

  16. From Bench to Bedside: Utility of the Rabbit Elastase Aneurysm Model in Pre-Clinical Studies of Intracranial Aneurysm Treatment

    PubMed Central

    Brinjikji, Waleed; Ding, Yong H; Kallmes, David F; Kadirvel, Ramanathan

    2016-01-01

    Summary Pre-clinical studies are important in helping practitioners and device developers improve techniques and tools for endovascular treatment of intracranial aneurysms. Thus, an understanding of the major animal models used in such studies is important. The New Zealand rabbit elastase induced arterial aneurysm of the common carotid artery is one of the most commonly used models in testing the safety and efficacy of new endovascular devices. In this review we discuss 1) various techniques used to create the aneurysm, 2) complications of aneurysm creation, 3) natural history of the arterial aneurysm, 4) histopathologic and hemodynamic features of the aneurysm 5) devices tested using this model and 6) weaknesses of the model. We demonstrate how pre-clinical studies using this model are applied in treatment of intracranial aneurysms in humans. The model has a similar hemodynamic, morphological and histologic characteristics to human aneurysms and demonstrates similar healing responses to coiling as human aneurysms. Despite these strengths however, the model does have many weaknesses including the fact that the model does not emulate the complex inflammatory processes affecting growing and ruptured aneurysms. Furthermore the model’s extracranial location affects its ability to be used in preclinical safety assessments of new devices. We conclude that the rabbit elastase model has characteristics that make it a simple and effective model for preclinical studies on the endovascular treatment of intracranial aneurysms however further work is needed to develop aneurysm models that simulate the histopathologic and morphologic characteristics of growing and ruptured aneurysms. PMID:25904642

  17. Preclinical evaluation of hydrogel sealed fluropassivated indigenous vascular prosthesis.

    PubMed

    Unnikrishnan, Madathipat; Umashankar, P R; Viswanathan, Sidharth; Savlania, Ajay; Joseph, Roy; Muraleedharan, C V; Agrawal, Vivek; Shenoy, Sachin J; Krishnan, Lissy K; Mohanan, P V; Sabareeswaran, A

    2017-11-01

    Polyethylene terephthalate (PET) graft, designed and developed at our institute for vascular reconstruction, is porous to promote optimal incorporation and neointima formation, requiring pre-clotting or biomodification by sealing the pores before implantation. The objective of this study was to characterize, test and perform preclinical evaluation of hydrogel (alginate dialdehyde cross-linked gelatin) sealed fluoropassivated PET vascular prosthesis in pig model, so as to avoid pre-clotting, for its safety and efficacy before employing the indigenous and less expensive graft for clinical use. Hydrogel sealed, fluoropassivated PET vascular prosthesis were tested for haemocompatibility and toxicity followed by small animal toxicology tests and in vivo experiments in pigs receiving implantation at thoracic aorta. All 33 animals received test as well as control grafts with a plan for phased explantation at 2, 12 and 26 weeks. All animals underwent completion angiogram at the end of procedure as well as before graft explantation. Haemocompatibility tests for haemolysis and toxicity tests showed no adverse events in tested mice and rabbits. Completion angiogram showed intact anastamosis and patent graft in each animal in post-operative period and at explantation. Gross and histopathological examination showed well-encapsulated grafts, clean glistening neointima and no evidence of thrombus in both test and control grafts. Hydrogel sealed, fluoropassivated PET vascular prosthesis was found non-toxic, haemocompatible and remained patent in in vivo studies at planned intervals.

  18. Preclinical evaluation of hydrogel sealed fluropassivated indigenous vascular prosthesis

    PubMed Central

    Unnikrishnan, Madathipat; Umashankar, P.R.; Viswanathan, Sidharth; Savlania, Ajay; Joseph, Roy; Muraleedharan, C.V.; Agrawal, Vivek; Shenoy, Sachin J.; Krishnan, Lissy K.; Mohanan, P.V.; Sabareeswaran, A.

    2017-01-01

    Background & objectives: Polyethylene terephthalate (PET) graft, designed and developed at our institute for vascular reconstruction, is porous to promote optimal incorporation and neointima formation, requiring pre-clotting or biomodification by sealing the pores before implantation. The objective of this study was to characterize, test and perform preclinical evaluation of hydrogel (alginate dialdehyde cross-linked gelatin) sealed fluoropassivated PET vascular prosthesis in pig model, so as to avoid pre-clotting, for its safety and efficacy before employing the indigenous and less expensive graft for clinical use. Methods: Hydrogel sealed, fluoropassivated PET vascular prosthesis were tested for haemocompatibility and toxicity followed by small animal toxicology tests and in vivo experiments in pigs receiving implantation at thoracic aorta. All 33 animals received test as well as control grafts with a plan for phased explantation at 2, 12 and 26 weeks. All animals underwent completion angiogram at the end of procedure as well as before graft explantation. Results: Haemocompatibility tests for haemolysis and toxicity tests showed no adverse events in tested mice and rabbits. Completion angiogram showed intact anastamosis and patent graft in each animal in post-operative period and at explantation. Gross and histopathological examination showed well-encapsulated grafts, clean glistening neointima and no evidence of thrombus in both test and control grafts. Interpretation & conclusions: Hydrogel sealed, fluoropassivated PET vascular prosthesis was found non-toxic, haemocompatible and remained patent in in vivo studies at planned intervals. PMID:29512608

  19. Common pitfalls in preclinical cancer target validation.

    PubMed

    Kaelin, William G

    2017-07-01

    An alarming number of papers from laboratories nominating new cancer drug targets contain findings that cannot be reproduced by others or are simply not robust enough to justify drug discovery efforts. This problem probably has many causes, including an underappreciation of the danger of being misled by off-target effects when using pharmacological or genetic perturbants in complex biological assays. This danger is particularly acute when, as is often the case in cancer pharmacology, the biological phenotype being measured is a 'down' readout (such as decreased proliferation, decreased viability or decreased tumour growth) that could simply reflect a nonspecific loss of cellular fitness. These problems are compounded by multiple hypothesis testing, such as when candidate targets emerge from high-throughput screens that interrogate multiple targets in parallel, and by a publication and promotion system that preferentially rewards positive findings. In this Perspective, I outline some of the common pitfalls in preclinical cancer target identification and some potential approaches to mitigate them.

  20. Hypophosphorylation of Ribosomal Protein S6 is a Molecular Mechanism Underlying Ischemic Tolerance Induced by either Hibernation or Preconditioning

    PubMed Central

    Miyake, Shin-ichi; Wakita, Hideaki; Bernstock, Joshua D.; Castri, Paola; Ruetzler, Christl; Miyake, Junko; Lee, Yang-ja; Hallenbeck, John M.

    2015-01-01

    Thirteen-lined ground squirrels (Ictidomys tridecemlineatus) have an extraordinary capacity to withstand prolonged and profound reductions of blood flow and oxygen delivery to brain without incurring any cellular damage. As such, the hibernation torpor of I. tridecemlineatus provides a valuable model of tolerance to ischemic stress. Herein, we report that during hibernation torpor, a marked reduction in the phosphorylation of the ribosomal protein S6 (rpS6) occurs within the brains of I. tridecemlineatus. Of note, rpS6 phosphorylation was shown to increase in the brains of rats that underwent an occlusion of the middle cerebral artery. However, such an increase was attenuated after the implementation of an ischemic preconditioning paradigm. In addition, cultured cortical neurons treated with the rpS6 kinase (S6K) inhibitors, D-glucosamine or PF4708671, displayed a decrease in rpS6 phosphorylation and a subsequent increase in tolerance to oxygen/glucose deprivation, an in vitro model of ischemic stroke. Collectively, such evidence suggests that the down regulation of rpS6 signal transduction may account for a substantial part of the observed increase in cellular tolerance to brain ischemia that occurs during hibernation torpor and after ischemic preconditioning. Further identification and characterization of the mechanisms used by hibernating species to increase ischemic tolerance may eventually clarify how the loss of homeostatic control that occurs during and after cerebral ischemia in the clinic can ultimately be minimized and/or prevented. PMID:26375300

  1. Preclinical Alzheimer disease and risk of falls

    PubMed Central

    Roe, Catherine M.; Grant, Elizabeth A.; Hollingsworth, Holly; Benzinger, Tammie L.; Fagan, Anne M.; Buckles, Virginia D.; Morris, John C.

    2013-01-01

    Objective: We determined the rate of falls among cognitively normal, community-dwelling older adults, some of whom had presumptive preclinical Alzheimer disease (AD) as detected by in vivo imaging of fibrillar amyloid plaques using Pittsburgh compound B (PiB) and PET and/or by assays of CSF to identify Aβ42, tau, and phosphorylated tau. Methods: We conducted a 12-month prospective cohort study to examine the cumulative incidence of falls. Participants were evaluated clinically and underwent PiB PET imaging and lumbar puncture. Falls were reported monthly using an individualized calendar journal returned by mail. A Cox proportional hazards model was used to test whether time to first fall was associated with each biomarker and the ratio of CSF tau/Aβ42 and CSF phosphorylated tau/Aβ42, after adjustment for common fall risk factors. Results: The sample (n = 125) was predominately female (62.4%) and white (96%) with a mean age of 74.4 years. When controlled for ability to perform activities of daily living, higher levels of PiB retention (hazard ratio = 2.95 [95% confidence interval 1.01–6.45], p = 0.05) and of CSF biomarker ratios (p < 0.001) were associated with a faster time to first fall. Conclusions: Presumptive preclinical AD is a risk factor for falls in older adults. This study suggests that subtle noncognitive changes that predispose older adults to falls are associated with AD and may precede detectable cognitive changes. PMID:23803314

  2. Non-intubated uniportal left-lower lobe upper segmentectomy (S6)

    PubMed Central

    Navarro-Martinez, Jose; Bolufer, Sergio; Sesma, Julio; Lirio, Francisco; Galiana, Maria; Rivera, Maria Jesus

    2017-01-01

    Worldwide accepted indications of anatomical segmentectomies are mainly early stage primary adenocarcinomas, pulmonary metastasis and benign conditions. Their performance through uniportal VATS has become more and more popular due to the less invasiveness of the whole procedure under this approach. Recently, many efforts have focused on non-intubated spontaneously breathing management of lobectomies and anatomical segmentectomies, although specific selection criteria and main advantages are not completely standardized. In a 62-year-old thin man with two pulmonary residual metastasis from sigma adenocarcinoma, after chemotherapy plus antiangiogenic treatment, we indicated a single-incision video-assisted left-lower lobe (LLL) upper segmentectomy (S6) under spontaneous breathing and intercostal blockade. Total operation time was 240 minutes. Chest tube was removed at 24 hours and the patient was discharge on postoperative day 2 without any complication. Non-intubated uniportal VATS is a safe and reasonable approach for lung-sparing resections in selected patients, although more evidence is required for selecting which patients can benefit more over standard intubated procedures. PMID:29078611

  3. Non-intubated uniportal left-lower lobe upper segmentectomy (S6).

    PubMed

    Galvez, Carlos; Navarro-Martinez, Jose; Bolufer, Sergio; Sesma, Julio; Lirio, Francisco; Galiana, Maria; Rivera, Maria Jesus

    2017-01-01

    Worldwide accepted indications of anatomical segmentectomies are mainly early stage primary adenocarcinomas, pulmonary metastasis and benign conditions. Their performance through uniportal VATS has become more and more popular due to the less invasiveness of the whole procedure under this approach. Recently, many efforts have focused on non-intubated spontaneously breathing management of lobectomies and anatomical segmentectomies, although specific selection criteria and main advantages are not completely standardized. In a 62-year-old thin man with two pulmonary residual metastasis from sigma adenocarcinoma, after chemotherapy plus antiangiogenic treatment, we indicated a single-incision video-assisted left-lower lobe (LLL) upper segmentectomy (S6) under spontaneous breathing and intercostal blockade. Total operation time was 240 minutes. Chest tube was removed at 24 hours and the patient was discharge on postoperative day 2 without any complication. Non-intubated uniportal VATS is a safe and reasonable approach for lung-sparing resections in selected patients, although more evidence is required for selecting which patients can benefit more over standard intubated procedures.

  4. CuInP 2S 6 Room Temperature Layered Ferroelectric

    DOE PAGES

    Belianinov, Alex; He, Qian; Dziaugys, Andrius; ...

    2015-05-01

    In this paper, we explore ferroelectric properties of cleaved 2-D flakes of copper indium thiophosphate, CuInP 2S 6 (CITP), and probe size effects along with limits of ferroelectric phase stability, by ambient and ultra high vacuum scanning probe microscopy. CITP belongs to the only material family known to display ferroelectric polarization in a van der Waals, layered crystal at room temperature and above. Our measurements directly reveal stable, ferroelectric polarization as evidenced by domain structures, switchable polarization, and hysteresis loops. We found that at room temperature the domain structure of flakes thicker than 100 nm is similar to the cleavedmore » bulk surfaces, whereas below 50 nm polarization disappears. We ascribe this behavior to a well-known instability of polarization due to depolarization field. Furthermore, polarization switching at high bias is also associated with ionic mobility, as evidenced both by macroscopic measurements and by formation of surface damage under the tip at a bias of 4 V—likely due to copper reduction. Mobile Cu ions may therefore also contribute to internal screening mechanisms. Finally, the existence of stable polarization in a van-der-Waals crystal naturally points toward new strategies for ultimate scaling of polar materials, quasi-2D, and single-layer materials with advanced and nonlinear dielectric properties that are presently not found in any members of the growing “graphene family”.« less

  5. Preclinical, Clinical, and Over-the-Counter Postmarketing Experience with a New Vaginal Cup: Menstrual Collection

    PubMed Central

    North, Barbara B.

    2011-01-01

    Abstract Background Menstrual cups have been available for decades, but their use is limited by bulky design and the need for multiple sizes. The Softcup® (Instead, Inc., San Diego, CA) is a simple single-size disposable over-the-counter (OTC) menstrual cup that compresses to tampon shape to facilitate insertion and can be worn during coitus. This report describes preclinical evaluation, clinical testing, and postmarketing monitoring of the Softcup. Methods Preclinical testing complied with U.S. Food and Drug Administration (FDA) guidelines and used standard United States Pharmacopoeia methodologies for assessment of potential toxicity. Clinical testing enrolled 406 women in seven U.S. centers. A detailed written questionnaire assessed safety, acceptability, and effectiveness for menstrual collection. Study safety parameters included pelvic examinations, Pap smears, colposcopy, urinalysis, vaginal pH, wet mounts, gram stain, and vaginal microflora cultures. Postmarketing surveillance of over 100 million Softcups has been conducted by the manufacturer and by the FDA Medwatch system. Results No toxicity or mutagenicity was observed in preclinical evaluations. In clinical testing, after three cycles of cup use, 37% of subjects rated the cup as better than, 29% as worse than, and 34% as equal to pads or tampons. The cup was preferred for comfort, dryness, and less odor. Cups received lower ratings for disposal and convenience. Eighty-one percent of enrolled women were able to insert and remove their first cup using only written instructions. Use difficulties resulting in study discontinuations included cramping (1%), leakage (1%), and improper fit (3%). No safety parameters were adversely affected. No significant health risks were reported during postmarketing surveillance. Conclusions These results demonstrate that a single-size vaginal device has no significant health risks and is acceptable to many women without the need for fitting or other medical services. PMID

  6. Preclinical, clinical, and over-the-counter postmarketing experience with a new vaginal cup: menstrual collection.

    PubMed

    North, Barbara B; Oldham, Michael J

    2011-02-01

    Menstrual cups have been available for decades, but their use is limited by bulky design and the need for multiple sizes. The Softcup® (Instead, Inc., San Diego, CA) is a simple single-size disposable over-the-counter (OTC) menstrual cup that compresses to tampon shape to facilitate insertion and can be worn during coitus. This report describes preclinical evaluation, clinical testing, and postmarketing monitoring of the Softcup. Preclinical testing complied with U.S. Food and Drug Administration (FDA) guidelines and used standard United States Pharmacopoeia methodologies for assessment of potential toxicity. Clinical testing enrolled 406 women in seven U.S. centers. A detailed written questionnaire assessed safety, acceptability, and effectiveness for menstrual collection. Study safety parameters included pelvic examinations, Pap smears, colposcopy, urinalysis, vaginal pH, wet mounts, gram stain, and vaginal microflora cultures. Postmarketing surveillance of over 100 million Softcups has been conducted by the manufacturer and by the FDA Medwatch system. No toxicity or mutagenicity was observed in preclinical evaluations. In clinical testing, after three cycles of cup use, 37% of subjects rated the cup as better than, 29% as worse than, and 34% as equal to pads or tampons. The cup was preferred for comfort, dryness, and less odor. Cups received lower ratings for disposal and convenience. Eighty-one percent of enrolled women were able to insert and remove their first cup using only written instructions. Use difficulties resulting in study discontinuations included cramping (1%), leakage (1%), and improper fit (3%). No safety parameters were adversely affected. No significant health risks were reported during postmarketing surveillance. These results demonstrate that a single-size vaginal device has no significant health risks and is acceptable to many women without the need for fitting or other medical services.

  7. The failure to detect drug-induced sensory loss in standard preclinical studies.

    PubMed

    Gauvin, David V; Abernathy, Matthew M; Tapp, Rachel L; Yoder, Joshua D; Dalton, Jill A; Baird, Theodore J

    2015-01-01

    Over the years a number of drugs have been approved for human use with limited signs of toxicity noted during preclinical risk assessment study designs but then show adverse events in compliant patients taking the drugs as prescribed within the first few years on the market. Loss or impairments in sensory systems, such as hearing, vision, taste, and smell have been reported to the FDA or have been described in the literature appearing in peer-reviewed scientific journals within the first five years of widespread use. This review highlights the interactive cross-modal compensation within sensory systems that can occur that reduces the likelihood of identifying these losses in less sentient animals used in standard preclinical toxicology and safety protocols. We provide some historical and experimental evidence to substantiate these sensory effects in and highlight the critical importance of detailed training of technicians on basic ethological, species-specific behaviors of all purpose-bred laboratory animals used in these study designs. We propose that the time, effort and cost of training technicians to be better able to identify and document very subtle changes in behavior will serve to increase the likelihood of early detection of biomarkers predictive of drug-induced sensory loss within current standard regulatory preclinical research protocols. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Preclinical and clinical properties of trimegestone: a potent and selective progestin.

    PubMed

    Sitruk-Ware, Regine; Bossemeyer, Ronald; Bouchard, Phillipe

    2007-06-01

    Trimegestone (TMG) is a novel, 19-norpregnane progestin with potent and selective properties. In preclinical studies, TMG has been shown to provide high endometrial selectivity. Further, TMG has high affinity and selectivity for the progesterone receptor and lacks the agonist effects of other steroid hormones. In clinical studies, TMG has been shown to have high endometrial safety and an improved bleeding profile along with improved tolerability compared with other progestins. In addition, TMG also does not impede the beneficial effects of estrogen, especially on bone, and does not compromise quality of life. The preclinical findings of lack of mineralocorticoid activity of TMG were supported in clinical findings, with neutral effect on body weight. Similarly, the smaller effect of TMG on the GABA-ergic (gamma-aminobutyric acid) system in preclinical studies is consistent with the improvement of central nervous system-related effects on depressed mood and sleep quality in clinical studies. Low-dose estradiol/TMG regimens provide rapid relief from menopausal symptoms, reducing the number and severity of hot flushes as effectively as 2 mg 17beta-estradiol/1 mg norethisterone acetate. Therefore, it may be concluded that TMG provides a clinically proven option in hormone therapy for both clinicians and patients.

  9. Endotoxicosis induced by Coxiella burnetii lipopolysaccharide stimulates a ribosomal protein S6 kinase: some properties of the partially purified enzyme.

    PubMed Central

    Picking, W D; Hackstadt, T; Paretsky, D

    1989-01-01

    Guinea pig endotoxicosis induced by lipopolysaccharide from Coxiella burnetii Nine Mile phase I stimulates phosphorylation of liver ribosomal protein S6, with a 50% increase at 12 h postinoculation. The responsible protein kinase (S6PK) has been partially purified from liver; its activity is independent of cyclic AMP and of Ca2+ plus phosphatidyl serine or diacylglycerol. The preparation has an apparent optimum concentration of 20 mM Mg2+, while Ca2+ and Mn2+ are each inhibitory at 2 mM. The apparent Km for ATP is 30 microM with intact ribosomes. Because of the central role of phosphorylation in metabolic regulation and a purported role of phosphorylated S6 in protein synthesis, the lipopolysaccharide-induced stimulation of S6PK suggests a significant regulatory role of such enzymes in the pathobiochemistry of Q fever infection and endotoxicosis. Images PMID:2807543

  10. p90 ribosomal S6 kinase: a potential therapeutic target in lung cancer.

    PubMed

    Poomakkoth, Noufira; Issa, Aya; Abdulrahman, Nabeel; Abdelaziz, Somaia Gamal; Mraiche, Fatima

    2016-01-14

    A global survey of cancer has shown that lung cancer is the most common cause of the new cancer cases and cancer deaths in men worldwide. The mortality from lung cancer is more than the combined mortality from breast, prostate and colorectal cancers. The two major histological types of lung cancer are non-small cell lung cancer (NSCLC) accounting for about 85 % of cases and small cell lung cancer accounting for 15 % of cases. NSCLC, the more prevalent form of lung cancer, is often diagnosed at an advanced stage and has a very poor prognosis. Many factors have been shown to contribute to the development of lung cancer in humans including tobacco smoking, exposure to environmental carcinogens (asbestos, or radon) and genetic factors. Despite the advances in treatment, lung cancer remains one of the leading causes of cancer death worldwide. Interestingly, the overall 5 year survival from lung cancer has not changed appreciably in the past 25 years. For this reason, novel and more effective treatments and strategies for NSCLC are critically needed. p90 ribosomal S6 kinase (RSK), a serine threonine kinase that lies downstream of the Ras-MAPK (mitogen activated protein kinase) cascade, has been demonstrated to be involved in the regulation of cell proliferation in various malignancies through indirect (e.g., modulation of transcription factors) or direct effects on the cell-cycle machinery. Increased expression of RSK has been demonstrated in various cancers, including lung cancer. This review focuses on the role of RSK in lung cancer and its potential therapeutic application.

  11. SUPPLEMENTARY COMPARISON: APMP.EM-S6: Bilateral supplementary comparison of resistance

    NASA Astrophysics Data System (ADS)

    Charoensook, Ajchara; Jassadajin, Chaiwat; Chen, Henry; Ricketts, Brian

    2004-01-01

    A bilateral supplementary comparison of resistance, APMP.EM-S6, was conducted between the National Institute of Metrology Thailand (NIMT) and the CSIRO National Measurement Laboratory of Australia (NML). The comparison covered seven values of resistance, 0.1 Ω, 1 Ω, 100 Ω, 10 kΩ, 100 kΩ, 1 MΩ and 100 MΩ. The 0.1 Ω resistor was a YEW type 2792, the 100 MΩ resistor was an IET type SRC and the other five resistors were Fluke type 742A. The resistors were supplied by NIMT, and NML was the pilot laboratory for the comparison. The measurements for the comparison were made between December 2003 and April 2004. The resistors were measured on three separate occasions by NIMT and between each of these occasions the resistors were sent to NML for measurement. The resistors of nominal values 0.1 Ω, 1 Ω, 100 Ω and 10 kΩ were measured as four-terminal resistors while the 100 kΩ, 1 MΩ and 100 MΩ resistors were measured as two-terminal resistors. The quantity En (the absolute value of the difference between the values obtained at the two laboratories divided by the root sum square of the expanded uncertainties of the two values) was calculated for each resistance value used in the comparison. In all cases En was less than 0.5. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the APMP, according to the provisions of the Mutual Recognition Arrangement (MRA).

  12. The Cytoplasmic Region of Inner Helix S6 Is an Important Determinant of Cardiac Ryanodine Receptor Channel Gating.

    PubMed

    Sun, Bo; Guo, Wenting; Tian, Xixi; Yao, Jinjing; Zhang, Lin; Wang, Ruiwu; Chen, S R Wayne

    2016-12-09

    The ryanodine receptor (RyR) channel pore is formed by four S6 inner helices, with its intracellular gate located at the S6 helix bundle crossing region. The cytoplasmic region of the extended S6 helix is held by the U motif of the central domain and is thought to control the opening and closing of the S6 helix bundle. However, the functional significance of the S6 cytoplasmic region in channel gating is unknown. Here we assessed the role of the S6 cytoplasmic region in the function of cardiac RyR (RyR2) via structure-guided site-directed mutagenesis. We mutated each residue in the S6 cytoplasmic region of the mouse RyR2 ( 4876 QQEQVKEDM 4884 ) and characterized their functional impact. We found that mutations Q4876A, V4880A, K4881A, and M4884A, located mainly on one side of the S6 helix that faces the U motif, enhanced basal channel activity and the sensitivity to Ca 2+ or caffeine activation, whereas mutations Q4877A, E4878A, Q4879A, and D4883A, located largely on the opposite side of S6, suppressed channel activity. Furthermore, V4880A, a cardiac arrhythmia-associated mutation, markedly enhanced the frequency of spontaneous openings and the sensitivity to cytosolic and luminal Ca 2+ activation of single RyR2 channels. V4880A also increased the propensity and reduced the threshold for arrhythmogenic spontaneous Ca 2+ release in HEK293 cells. Collectively, our data suggest that interactions between the cytoplasmic region of S6 and the U motif of RyR2 are important for stabilizing the closed state of the channel. Mutations in the S6/U motif domain interface likely destabilize the closed state of RyR2, resulting in enhanced basal channel activity and sensitivity to activation and increased propensity for spontaneous Ca 2+ release and cardiac arrhythmias. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. A Genome-Wide siRNA Screen in Mammalian Cells for Regulators of S6 Phosphorylation

    PubMed Central

    Papageorgiou, Angela; Rapley, Joseph; Mesirov, Jill P.; Tamayo, Pablo; Avruch, Joseph

    2015-01-01

    mTOR complex1, the major regulator of mRNA translation in all eukaryotic cells, is strongly activated in most cancers. We performed a genome-wide RNAi screen in a human cancer cell line, seeking genes that regulate S6 phosphorylation, readout of mTORC1 activity. Applying a stringent selection, we retrieved nearly 600 genes wherein at least two RNAis gave significant reduction in S6-P. This cohort contains known regulators of mTOR complex 1 and is significantly enriched in genes whose depletion affects the proliferation/viability of the large set of cancer cell lines in the Achilles database in a manner paralleling that caused by mTOR depletion. We next examined the effect of RNAi pools directed at 534 of these gene products on S6-P in TSC1 null mouse embryo fibroblasts. 76 RNAis reduced S6 phosphorylation significantly in 2 or 3 replicates. Surprisingly, among this cohort of genes the only elements previously associated with the maintenance of mTORC1 activity are two subunits of the vacuolar ATPase and the CUL4 subunit DDB1. RNAi against a second set of 84 targets reduced S6-P in only one of three replicates. However, an indication that this group also bears attention is the presence of rpS6KB1 itself, Rac1 and MAP4K3, a protein kinase that supports amino acid signaling to rpS6KB1. The finding that S6 phosphorylation requires a previously unidentified, functionally diverse cohort of genes that participate in fundamental cellular processes such as mRNA translation, RNA processing, DNA repair and metabolism suggests the operation of feedback pathways in the regulation of mTORC1 operating through novel mechanisms. PMID:25790369

  14. Haloperidol Regulates the State of Phosphorylation of Ribosomal Protein S6 via Activation of PKA and Phosphorylation of DARPP-32

    PubMed Central

    Valjent, Emmanuel; Bertran-Gonzalez, Jesus; Bowling, Heather; Lopez, Sébastien; Santini, Emanuela; Matamales, Miriam; Bonito-Oliva, Alessandra; Hervé, Denis; Hoeffer, Charles; Klann, Eric; Girault, Jean-Antoine; Fisone, Gilberto

    2011-01-01

    Administration of typical antipsychotic drugs, such as haloperidol, promotes cAMP-dependent signaling in the medium spiny neurons (MSNs) of the striatum. In this study, we have examined the effect of haloperidol on the state of phosphorylation of the ribosomal protein S6 (rpS6), a component of the small 40S ribosomal subunit. We found that haloperidol increases the phosphorylation of rpS6 at the dual site Ser235/236, which is involved in the regulation of mRNA translation. This effect was exerted in the MSNs of the indirect pathway, which express specifically dopamine D2 receptors (D2Rs) and adenosine A2 receptors (A2ARs). The effect of haloperidol was decreased by blockade of A2ARs or by genetic attenuation of the Gαolf protein, which couples A2ARs to activation of adenylyl cyclase. Moreover, stimulation of cAMP-dependent protein kinase A (PKA) increased Ser235/236 phosphorylation in cultured striatal neurons. The ability of haloperidol to promote rpS6 phosphorylation was abolished in knock-in mice deficient for PKA activation of the protein phosphatase-1 inhibitor, dopamine- and cAMP-regulated phosphoprotein of 32 kDa. In contrast, pharmacological or genetic inactivation of p70 rpS6 kinase 1, or extracellular signal-regulated kinases did not affect haloperidol-induced rpS6 phosphorylation. These results identify PKA as a major rpS6 kinase in neuronal cells and suggest that regulation of protein synthesis through rpS6 may be a potential target of antipsychotic drugs. PMID:21814187

  15. The discovery of potent ribosomal S6 kinase inhibitors by high-throughput screening and structure-guided drug design

    PubMed Central

    Kalusa, Andrew; Cano, Celine; Travers, Jon; Boxall, Kathy; Chow, Chiau Ling; Burns, Sam; Schmitt, Jessica; Pickard, Lisa; Barillari, Caterina; McAndrew, P. Craig; Clarke, Paul A.; Linardopoulos, Spiros; Griffin, Roger J.; Aherne, G. Wynne; Raynaud, Florence I.; Workman, Paul; Jones, Keith; van Montfort, Rob L.M.

    2013-01-01

    The ribosomal P70 S6 kinases play a crucial role in PI3K/mTOR regulated signalling pathways and are therefore potential targets for the treatment of a variety of diseases including diabetes and cancer. In this study we describe the identification of three series of chemically distinct S6K1 inhibitors. In addition, we report a novel PKA-S6K1 chimeric protein with five mutations in or near its ATP-binding site, which was used to determine the binding mode of two of the three inhibitor series, and provided a robust system to aid the optimisation of the oxadiazole-substituted benzimidazole inhibitor series. We show that the resulting oxadiazole-substituted aza-benzimidazole is a potent and ligand efficient S6 kinase inhibitor, which blocks the phosphorylation of RPS6 at Ser235/236 in TSC negative HCV29 human bladder cancer cells by inhibiting S6 kinase activity and thus provides a useful tool compound to investigate the function of S6 kinases. PMID:24072592

  16. Overexpression of Notch3 and pS6 Is Associated with Poor Prognosis in Human Ovarian Epithelial Cancer.

    PubMed

    Liu, Zhaoxia; Yun, Rongna; Yu, Xiaolin; Hu, Hui; Huang, Genhua; Tan, Buzhen; Chen, Tingtao

    2016-01-01

    Notch3 and pS6 play important roles in tumor angiogenesis. To assess the expression of Notch3 and pS6 in Chinese ovarian epithelial cancer patients, a ten-year follow-up study was performed in ovarian epithelial cancer tissues from 120 specimens of human ovarian epithelial cancer, 30 specimens from benign ovarian tumors, and 30 samples from healthy ovaries by immunohistochemistry. The results indicate that the expression of Notch3 and pS6 was higher in ovarian epithelial cancer than in normal ovary tissues and in benign ovarian tumor tissues (p < 0.01). In tumor tissues, Notch3 expression and pS6 expression were negatively associated with age (p > 0.05) but positively associated with clinical stage, pathological grading, histologic type, lymph node metastasis, and ascites (p < 0.05 or p < 0.01). A follow-up survey of 64 patients with ovarian epithelial cancer showed that patients with high Notch3 and pS6 expression had a shorter survival time (p < 0.01), in which the clinical stage (p < 0.05) and Notch3 expression (p < 0.01) played important roles. In conclusion, Notch3 and pS6 are significantly related to ovarian epithelial cancer development and prognosis, and their combination represents a potential biomarker and therapeutic target in ovarian tumor angiogenesis.

  17. 77 FR 29665 - International Conference on Harmonisation; Addendum to International Conference on Harmonisation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-18

    ... Preclinical Safety Evaluation of Biotechnology-Derived Pharmaceuticals; Availability AGENCY: Food and Drug... availability of a guidance entitled ``S6 Addendum to Preclinical Safety Evaluation of Biotechnology-Derived... implementation of the ICH guidance [[Page 29666

  18. Preclinical Mouse Cancer Models: A Maze of Opportunities and Challenges

    PubMed Central

    Day, Chi-Ping; Merlino, Glenn; Van Dyke, Terry

    2015-01-01

    Significant advances have been made in developing novel therapeutics for cancer treatment, and targeted therapies have revolutionized the treatment of some cancers. Despite the promise, only about five percent of new cancer drugs are approved, and most fail due to lack of efficacy. The indication is that current preclinical methods are limited in predicting successful outcomes. Such failure exacts enormous cost, both financial and in the quality of human life. This primer explores the current status, promise and challenges of preclinical evaluation in advanced mouse cancer models and briefly addresses emerging models for early-stage preclinical development. PMID:26406370

  19. S6K is a morphogenic protein with a mechanism involving Filamin-A phosphorylation and phosphatidic acid binding.

    PubMed

    Henkels, Karen M; Mallets, Elizabeth R; Dennis, Patrick B; Gomez-Cambronero, Julian

    2015-04-01

    Change of cell shape in vivo plays many roles that are central to life itself, such as embryonic development, inflammation, wound healing, and pathologic processes such as cancer metastasis. Nonetheless, the spatiotemporal mechanisms that control the concerted regulation of cell shape remain understudied. Here, we show that ribosomal S6K, which is normally considered a protein involved in protein translation, is a morphogenic protein. Its presence in cells alters the overall organization of the cell surface and cell circularity [(4π × area)/(perimeter)(2)] from 0.47 ± 0.06 units in mock-treated cells to 0.09 ± 0.03 units in S6K-overexpressing macrophages causing stellation and arborization of cell shape. This effect was partially reversed in cells expressing a kinase-inactive S6K mutant and was fully reversed in cells silenced with small interference RNA. Equally important is that S6K is itself regulated by phospholipids, specifically phosphatidic acid, whereby 300 nM 1,2-dioleoyl-sn-glycero-3-phosphate (DOPA), but not the control 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), binds directly to S6K and causes an ∼ 2.9-fold increase in S6K catalytic activity. This was followed by an increase in Filamin A (FLNA) functionality as measured by phospho-FLNA (S(2152)) expression and by a subsequent elevation of actin nucleation. This reliance of S6K on phosphatidic acid (PA), a curvature-inducing phospholipid, explained the extra-large perimeter of cells that overexpressed S6K. Furthermore, the diversity of the response to S6K in several unrelated cell types (fibroblasts, leukocytes, and invasive cancer cells) that we report here indicates the existence of an underlying common mechanism in mammalian cells. This new signaling set, PA-S6K-FLNA-actin, sheds light for the first time into the morphogenic pathway of cytoskeletal structures that are crucial for adhesion and cell locomotion during inflammation and metastasis. © FASEB.

  20. Hand Safety

    MedlinePlus

    ... Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring Fireworks Safety Español Artritis ... Lawnmower Safety Snowblower safety Pumpkin Carving Gardening Safety Turkey Carving Removing a Ring Fireworks Safety Español Artritis ...

  1. Small Molecular TRAIL Inducer ONC201 Induces Death in Lung Cancer Cells: A Preclinical Study

    PubMed Central

    Feng, Yuan; Zhou, Jihong; Li, Zhanhua; Jiang, Ying; Zhou, Ying

    2016-01-01

    Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) selectively targets cancer cells. The present preclinical study investigated the anti-cancer efficiency of ONC201, a first-in-class small molecule TRAIL inducer, in lung cancer cells. We showed that ONC201 was cytotoxic and anti-proliferative in both established (A549 and H460 lines) and primary human lung cancer cells. It was yet non-cytotoxic to normal lung epithelial cells. Further, ONC201 induced exogenous apoptosis activation in lung cancer cells, which was evidenced by TRAIL/death receptor-5 (DR5) induction and caspase-8 activation. The caspase-8 inhibitor or TRAIL/DR5 siRNA knockdown alleviated ONC201’s cytotoxicity against lung cancer cells. Molecularly, ONC201 in-activated Akt-S6K1 and Erk signalings in lung cancer cells, causing Foxo3a nuclear translocation. For the in vivo studies, intraperitoneal injection of ONC201 at well-tolerated doses significantly inhibited xenografted A549 tumor growth in severe combined immunodeficient (SCID) mice. Further, ONC201 administration induced TRAIL/DR5 expression, yet inactivated Akt-S6K1 and Erk in tumor tissues. These results of the study demonstrates the potent anti-lung cancer activity by ONC201. PMID:27626799

  2. Small Molecular TRAIL Inducer ONC201 Induces Death in Lung Cancer Cells: A Preclinical Study.

    PubMed

    Feng, Yuan; Zhou, Jihong; Li, Zhanhua; Jiang, Ying; Zhou, Ying

    2016-01-01

    Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) selectively targets cancer cells. The present preclinical study investigated the anti-cancer efficiency of ONC201, a first-in-class small molecule TRAIL inducer, in lung cancer cells. We showed that ONC201 was cytotoxic and anti-proliferative in both established (A549 and H460 lines) and primary human lung cancer cells. It was yet non-cytotoxic to normal lung epithelial cells. Further, ONC201 induced exogenous apoptosis activation in lung cancer cells, which was evidenced by TRAIL/death receptor-5 (DR5) induction and caspase-8 activation. The caspase-8 inhibitor or TRAIL/DR5 siRNA knockdown alleviated ONC201's cytotoxicity against lung cancer cells. Molecularly, ONC201 in-activated Akt-S6K1 and Erk signalings in lung cancer cells, causing Foxo3a nuclear translocation. For the in vivo studies, intraperitoneal injection of ONC201 at well-tolerated doses significantly inhibited xenografted A549 tumor growth in severe combined immunodeficient (SCID) mice. Further, ONC201 administration induced TRAIL/DR5 expression, yet inactivated Akt-S6K1 and Erk in tumor tissues. These results of the study demonstrates the potent anti-lung cancer activity by ONC201.

  3. Preclinical fluorescent mouse models of pancreatic cancer

    NASA Astrophysics Data System (ADS)

    Bouvet, Michael; Hoffman, Robert M.

    2007-02-01

    Here we describe our cumulative experience with the development and preclinical application of several highly fluorescent, clinically-relevant, metastatic orthotopic mouse models of pancreatic cancer. These models utilize the human pancreatic cancer cell lines which have been genetically engineered to selectively express high levels of the bioluminescent green fluorescent (GFP) or red fluorescent protein (RFP). Fluorescent tumors are established subcutaneously in nude mice, and tumor fragments are then surgically transplanted onto the pancreas. Locoregional tumor growth and distant metastasis of these orthotopic implants occurs spontaneously and rapidly throughout the abdomen in a manner consistent with clinical human disease. Highly specific, high-resolution, real-time visualization of tumor growth and metastasis may be achieved in vivo without the need for contrast agents, invasive techniques, or expensive imaging equipment. We have shown a high correlation between florescent optical imaging and magnetic resonance imaging in these models. Alternatively, transplantation of RFP-expressing tumor fragments onto the pancreas of GFP-expressing transgenic mice may be used to facilitate visualization of tumor-host interaction between the pancreatic tumor fragments and host-derived stroma and vasculature. Such in vivo models have enabled us to serially visualize and acquire images of the progression of pancreatic cancer in the live animal, and to demonstrate the real-time antitumor and antimetastatic effects of several novel therapeutic strategies on pancreatic malignancy. These fluorescent models are therefore powerful and reliable tools with which to investigate human pancreatic cancer and therapeutic strategies directed against it.

  4. Pharmacological enhancement of fear reduction: preclinical models

    PubMed Central

    Graham, Bronwyn M; Langton, Julia M; Richardson, Rick

    2011-01-01

    Anxiety disorders have a high prevalence, and despite the substantial advances in the psychological treatment of anxiety, relapse is still a common problem. One approach to improving existing psychological treatments for anxiety has been to develop pharmacological agents that can be used to enhance the processes underlying exposure therapy, which is the most commonly used and empirically validated psychological treatment for anxiety during which individuals are taught to appropriately inhibit fear. Animal models of exposure therapy, particularly fear extinction, have proved to be a very useful way of examining the neural and molecular correlates of fear inhibition, which has in turn led to the identification of numerous drugs that enhance these processes in rats. Several of these drugs have subsequently been tested as novel pharmacological adjuncts to exposure therapy in humans with a range of anxiety disorders. The purpose of this review is to outline the key animal models of exposure therapy and to describe how these have been used to develop potential pharmacological adjuncts for anxiety disorders. Drugs that are currently in clinical use, as well as those currently in the preclinical stages of investigation, are described. LINKED ARTICLES This article is part of a themed issue on Translational Neuropharmacology. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.164.issue-4 PMID:21175588

  5. Preclinical studies of alcohol binge drinking

    PubMed Central

    Crabbe, John C.; Harris, R. Adron; Koob, George F.

    2011-01-01

    Binge drinking is prevalent and has serious biomedical consequences. In children, adolescents, and young adults, it is a prominent risk factor for later development of alcohol-use disorders. Many preclinical models have been employed to study the genetic risks for and biomedical consequences of alcohol drinking. However, these models historically did not result in blood-alcohol concentrations (BACs) exceding 80 mg%; this relatively modest level is the threshold that currently defines a binge session, according to the NIAAA and CDC. Nevertheless, in alcohol-dependent rodents, binge drinking has been well documented. Key neurobiological substrates localized to brain reward and stress systems have been identified. Studies of newer models of binge drinking without dependence are reviewed here. In these models, rodents, non-human primates, and flies will drink enough to reach high BACs. They often display observable signs of intoxication. The neurobiological consequences of these episodes of binge drinking without dependence are reviewed, preliminary evidence for roles for GABA, glutamate, opioid peptides, and corticotropin releasing factor are discussed, as is the need for more work to identify the antecedents and consequences of binge drinking in both animal models and humans. PMID:21272009

  6. Radiolabeled bombesin derivatives for preclinical oncological imaging

    PubMed Central

    de Aguiar Ferreira, Carolina; Fuscaldi, Leonardo Lima; Townsend, Danyelle M.; Rubello, Domenico; de Barros, André Luís Branco

    2017-01-01

    Despite efforts, cancer is still one of the leading causes of morbidity and mortality worldwide, with approximately 14 million new cases and 8.2 million cancer-related deaths each year, according to the World Health Organization. Among the strategies to reduce cancer progression and improving its management, implementing early detection technologies is crucial. Based on the fact that several types of cancer cells overexpress surface receptors, small molecule ligands, such as peptides, have been developed to allow tumor identification at earlier stages. Allied with imaging techniques such as PET and SPECT, radiolabeled peptides play a pivotal role in nuclear medicine. Bombesin, a peptide of 14 amino acids, is an amphibian homolog to the mammalian gastrin-releasing peptide (GRP), that has been extensively studied as a targeting ligand for diagnosis and therapy of GRP positive tumors, such as breast, pancreas, lungs and prostate cancers. In this context, herein we provide a review of reported bombesin derivatives radiolabeled with a multitude of radioactive isotopes for diagnostic purposes in the preclinical setting. Moreover, since animal models are highly relevant for assessing the potential of clinical translation of this radiopeptides, a brief report of the currently used GRP-positive tumor-bearing animal models is described. PMID:28040598

  7. PD and PDT for hepatoblastoma? Preclinical considerations

    NASA Astrophysics Data System (ADS)

    Stepp, Herbert; Bergmann, Florian; Johansson, Ann; Heide, Michael; Metzger, Roman; Rolle, Udo; Till, Holger

    2011-07-01

    Objective: Provide preclinical data on the feasibility of 5-aminolevulinic acid (5-ALA) -based photodetection (PD) and Photodynamic Therapy (PDT) of early childhood tumors. Methods: Hepatoblastoma (HuH6), neuroblastoma (MHH-NB11) and N1-fibroblast cell lines were tested for their relative capacities to synthesize Protoporphyrin IX (PpIX) from 5-ALA and for their susceptibility to PDT in vitro. HuH6-cells were also inoculated in the peritoneum of rats. The pharmacokinetics of porphyrin accumulation was measured in 9 rats by laparoscopic spectroscopy. 5-ALA was applied by i.p. injection of 500 mg/kg bw. In another 21 animals, tumors (n=20), liver (n=5) and peritoneum (n=4) were treated by PDT laparoscopically. 48 h after irradiation, animals were again incubated with 5-ALA and then sacrificed and tissues were removed for further investigation. Results: Both tumor cell lines showed higher levels of porphyrin fluorescence than the fibroblasts. Cell viability testing proved the HuH6 cells to be most susceptible to PDT. Pharmacokinetic measurements of PpIX in xenografted tumors showed a peak at 80-200 min after i.p. injection of 5-ALA. Irradiation resulted in pronounced photobleaching at all irradiated sites and necrosis of tumor and liver tissue, whereas peritoneum appeared to remain unaffected. Necrosis induced by PDT could be seen in fluorescence microscopy due to the lack of porphyrin synthesis in necrotic tissue after the re-incubation with 5-ALA.

  8. [Preclinical horizon of depression in adults].

    PubMed

    Jiménez-Báez, María Valeria; Márquez-González, Horacio; Monsreal-Góngora, Juan Leonardo; Góngora-González, Gonzalo; Sandoval-Jurado, Luis; Boquer-Hernández, Rubén

    2016-01-01

    Identify factors related to preclinical depression in healthy adults, their risk factors and concordance with family doctor diagnostic. Case-control study in adult from family medicine consulting room. Beck inventory for depression was applied. The correlation between depression and the diagnosis by the family physician was evaluated. Odds ratio (OR) was determined. Involved 138 patients randomly from four family medicine units (FMU) in the Northern Region of Quintana Roo, Mexico. The mean age 34.9 ± 11.4 years, 55.8% women, prevalence for depression was 26.1%. Being male OR: 3.76; 95% CI: 1.69-8.36, under 30 years OR: 2.76; 95% CI: 1.27-5.99, low socioeconomic status (SES) OR: 2.11; 95% CI: 0.97-4.59 and be married OR: 3.22; 95% CI: 1.41.-7.36 had depression risk. Diagnosis by the family physician and inventory Beck. Kappa Index 0.2, 95% CI: -0057-0176; p = 0.05. Almost a third of young adults have some depression degree in family medicine consulting room, it is necessary a depression screening for male patients, low SES, married, and under 30 years old, attending medical consultation familiar, for a early diagnosis and improve prognosis.

  9. Emerging preclinical pharmacological targets for Parkinson's disease

    PubMed Central

    More, Sandeep Vasant; Choi, Dong-Kug

    2016-01-01

    Parkinson's disease (PD) is a progressive neurological condition caused by the degeneration of dopaminergic neurons in the basal ganglia. It is the most prevalent form of Parkinsonism, categorized by cardinal features such as bradykinesia, rigidity, tremors, and postural instability. Due to the multicentric pathology of PD involving inflammation, oxidative stress, excitotoxicity, apoptosis, and protein aggregation, it has become difficult to pin-point a single therapeutic target and evaluate its potential application. Currently available drugs for treating PD provide only symptomatic relief and do not decrease or avert disease progression resulting in poor patient satisfaction and compliance. Significant amount of understanding concerning the pathophysiology of PD has offered a range of potential targets for PD. Several emerging targets including AAV-hAADC gene therapy, phosphodiesterase-4, potassium channels, myeloperoxidase, acetylcholinesterase, MAO-B, dopamine, A2A, mGlu5, and 5-HT-1A/1B receptors are in different stages of clinical development. Additionally, alternative interventions such as deep brain stimulation, thalamotomy, transcranial magnetic stimulation, and gamma knife surgery, are also being developed for patients with advanced PD. As much as these therapeutic targets hold potential to delay the onset and reverse the disease, more targets and alternative interventions need to be examined in different stages of PD. In this review, we discuss various emerging preclinical pharmacological targets that may serve as a new promising neuroprotective strategy that could actually help alleviate PD and its symptoms. PMID:26988916

  10. Preclinical animal anxiety research - flaws and prejudices.

    PubMed

    Ennaceur, Abdelkader; Chazot, Paul L

    2016-04-01

    The current tests of anxiety in mice and rats used in preclinical research include the elevated plus-maze (EPM) or zero-maze (EZM), the light/dark box (LDB), and the open-field (OF). They are currently very popular, and despite their poor achievements, they continue to exert considerable constraints on the development of novel approaches. Hence, a novel anxiety test needs to be compared with these traditional tests, and assessed against various factors that were identified as a source of their inconsistent and contradictory results. These constraints are very costly, and they are in most cases useless as they originate from flawed methodologies. In the present report, we argue that the EPM or EZM, LDB, and OF do not provide unequivocal measures of anxiety; that there is no evidence of motivation conflict involved in these tests. They can be considered at best, tests of natural preference for unlit and/or enclosed spaces. We also argued that pharmacological validation of a behavioral test is an inappropriate approach; it stems from the confusion of animal models of human behavior with animal models of pathophysiology. A behavioral test is developed to detect not to produce symptoms, and a drug is used to validate an identified physiological target. In order to overcome the major methodological flaws in animal anxiety studies, we proposed an open space anxiety test, a 3D maze, which is described here with highlights of its various advantages over to the traditional tests.

  11. Activation of p70S6 Kinase-1 in Mesenchymal Stem Cells Is Essential to Lung Tissue Repair.

    PubMed

    Takeda, Katsuyuki; Ning, Fangkun; Domenico, Joanne; Okamoto, Masakazu; Ashino, Shigeru; Kim, Sang-Ha; Jeong, Yi Yeong; Shiraishi, Yoshiki; Terada, Naohiro; Sutherland, Everett Rand; Gelfand, Erwin W

    2018-05-05

    All-trans retinoic acid (ATRA) or mesenchymal stem cells (MSCs) have been shown to promote lung tissue regeneration in animal models of emphysema. However, the reparative effects of the combination of the two and the role of p70S6 kinase-1 (p70S6k1) activation in the repair process have not been defined. Twenty-one days after intratracheal instillation of porcine pancreatic elastase (PPE), MSC and/or 10 days of ATRA treatment was initiated. Thirty-two days later, static lung compliance (Cst), mean linear intercepts (MLIs), and alveolar surface area (S) were measured. After PPE, mice demonstrated increased values of Cst and MLI, and decreased S values. Both ATRA and MSC transfer were individually effective in improving these outcomes while the combination of ATRA and MSCs was even more effective. The combination of p70S6k1 -/- MSCs transfer followed by ATRA demonstrated only modest effects, and rapamycin treatment of recipients with wild-type (WT) MSCs and ATRA failed to show any effect. However, transfer of p70S6k1 over-expressing-MSCs together with ATRA resulted in further improvements over those seen following WT MSCs together with ATRA. ATRA activated p70S6k1 in MSCs in vitro, which was completely inhibited by rapamycin. Tracking of transferred MSCs following ATRA revealed enhanced accumulation and extended survival of MSCs in recipient lungs following PPE but not vehicle instillation. These data suggest that in MSCs, p70S6k1 activation plays a critical role in ATRA-enhanced lung tissue repair, mediated in part by prolonged survival of transferred MSCs. p70S6k1-activated MSCs may represent a novel therapeutic approach to reverse the lung damage seen in emphysema. Stem Cells Translational Medicine 2018. © 2018 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  12. Elevated ERK/p90 ribosomal S6 kinase activity underlies audiogenic seizure susceptibility in fragile X mice.

    PubMed

    Sawicka, Kirsty; Pyronneau, Alexander; Chao, Miranda; Bennett, Michael V L; Zukin, R Suzanne

    2016-10-11

    Fragile X syndrome (FXS) is the most common heritable cause of intellectual disability and a leading genetic form of autism. The Fmr1 KO mouse, a model of FXS, exhibits elevated translation in the hippocampus and the cortex. ERK (extracellular signal-regulated kinase) and mTOR (mechanistic target of rapamycin) signaling regulate protein synthesis by activating downstream targets critical to translation initiation and elongation and are known to contribute to hippocampal defects in fragile X. Here we show that the effect of loss of fragile X mental retardation protein (FMRP) on these pathways is brain region specific. In contrast to the hippocampus, ERK (but not mTOR) signaling is elevated in the neocortex of fragile X mice. Phosphorylation of ribosomal protein S6, typically a downstream target of mTOR, is elevated in the neocortex, despite normal mTOR activity. This is significant in that S6 phosphorylation facilitates translation, correlates with neuronal activation, and is altered in neurodevelopmental disorders. We show that in fragile X mice, S6 is regulated by ERK via the "alternative" S6 kinase p90-ribosomal S6 kinase (RSK), as evidenced by the site of elevated phosphorylation and the finding that ERK inhibition corrects elevated RSK and S6 activity. These findings indicate that signaling networks are altered in the neocortex of fragile X mice such that S6 phosphorylation receives aberrant input from ERK/RSK. Importantly, an RSK inhibitor reduces susceptibility to audiogenic seizures in fragile X mice. Our findings identify RSK as a therapeutic target for fragile X and suggest the therapeutic potential of drugs for the treatment of FXS may vary in a brain-region-specific manner.

  13. Inhibition of miR-128-3p by Tongxinluo Protects Human Cardiomyocytes from Ischemia/reperfusion Injury via Upregulation of p70s6k1/p-p70s6k1

    PubMed Central

    Chen, Gui-hao; Xu, Chuan-sheng; Zhang, Jie; Li, Qing; Cui, He-he; Li, Xiang-dong; Chang, Li-ping; Tang, Rui-jie; Xu, Jun-yan; Tian, Xia-qiu; Huang, Pei-sen; Xu, Jun; Jin, Chen; Yang, Yue-jin

    2017-01-01

    Background and Aims: Tongxinluo (TXL) is a multifunctional traditional Chinese medicine that has been widely used to treat cardiovascular and cerebrovascular diseases. However, no studies have explored whether TXL can protect human cardiomyocytes (HCMs) from ischemia/reperfusion (I/R) injury. Reperfusion Injury Salvage Kinase (RISK) pathway activation was previously demonstrated to protect the hearts against I/R injury and it is generally activated via Akt or (and) Erk 1/2, and their common downstream protein, ribosomal protein S6 kinase (p70s6k). In addition, prior studies proved that TXL treatment of cells promoted secretion of VEGF, which could be stimulated by the increased phosphorylation of one p70s6k subtype, p70s6k1. Consequently, we hypothesized TXL could protect HCMs from I/R injury by activating p70s6k1 and investigated the underlying mechanism. Methods and Results: HCMs were exposed to hypoxia (18 h) and reoxygenation (2 h) (H/R), with or without TXL pretreatment. H/R reduced mitochondrial membrane potential, increased bax/bcl-2 ratios and cytochrome C levels and induced HCM apoptosis. TXL preconditioning reversed these H/R-induced changes in a dose-dependent manner and was most effective at 400 μg/mL. The anti-apoptotic effect of TXL was abrogated by rapamycin, an inhibitor of p70s6k. However, inhibitors of Erk1/2 (U0126) or Akt (LY294002) failed to inhibit the protective effect of TXL. TXL increased p70s6k1 expression and, thus, enhanced its phosphorylation. Furthermore, transfection of cardiomyocytes with siRNA to p70s6k1 abolished the protective effects of TXL. Among the micro-RNAs (miR-145-5p, miR-128-3p and miR-497-5p) previously reported to target p70s6k1, TXL downregulated miR-128-3p in HCMs during H/R, but had no effects on miR-145-5p and miR-497-5p. An in vivo study confirmed the role of the p70s6k1 pathway in the infarct-sparing effect of TXL, demonstrating that TXL decreased miR-128-3p levels in the rat myocardium during I/R. Transfection

  14. Concise Review: Mesenchymal Stem (Stromal) Cells: Biology and Preclinical Evidence for Therapeutic Potential for Organ Dysfunction Following Trauma or Sepsis.

    PubMed

    Matthay, Michael A; Pati, Shibani; Lee, Jae-Woo

    2017-02-01

    Several experimental studies have provided evidence that bone-marrow derived mesenchymal stem (stromal) cells (MSC) may be effective in treating critically ill surgical patients who develop traumatic brain injury, acute renal failure, or the acute respiratory distress syndrome. There is also preclinical evidence that MSC may be effective in treating sepsis-induced organ failure, including evidence that MSC have antimicrobial properties. This review considers preclinical studies with direct relevance to organ failure following trauma, sepsis or major infections that apply to critically ill patients. Progress has been made in understanding the mechanisms of benefit, including MSC release of paracrine factors, transfer of mitochondria, and elaboration of exosomes and microvesicles. Regardless of how well they are designed, preclinical studies have limitations in modeling the complexity of clinical syndromes, especially in patients who are critically ill. In order to facilitate translation of the preclinical studies of MSC to critically ill patients, there will need to be more standardization regarding MSC production with a focus on culture methods and cell characterization. Finally, well designed clinical trials will be needed in critically ill patient to assess safety and efficacy. Stem Cells 2017;35:316-324. © 2016 AlphaMed Press.

  15. CAP--advancing the evaluation of preclinical Alzheimer disease treatments.

    PubMed

    Reiman, Eric M; Langbaum, Jessica B; Tariot, Pierre N; Lopera, Francisco; Bateman, Randall J; Morris, John C; Sperling, Reisa A; Aisen, Paul S; Roses, Allen D; Welsh-Bohmer, Kathleen A; Carrillo, Maria C; Weninger, Stacie

    2016-01-01

    If we are to find treatments to postpone, reduce the risk of, or completely prevent the clinical onset of Alzheimer disease (AD), we need faster methods to evaluate promising preclinical AD treatments, new ways to work together in support of common goals, and a determination to expedite the initiation and performance of preclinical AD trials. In this article, we note some of the current challenges, opportunities and emerging strategies in preclinical AD treatment. We describe the Collaboration for Alzheimer's Prevention (CAP)-a convening, harmonizing and consensus-building initiative to help stakeholders advance AD prevention research with rigour, care and maximal impact-and we demonstrate the impact of CAP on the goals and design of new preclinical AD trials.

  16. CAP—advancing the evaluation of preclinical Alzheimer disease treatments

    PubMed Central

    Reiman, Eric M.; Langbaum, Jessica B.; Tariot, Pierre N.; Lopera, Francisco; Bateman, Randall J.; Morris, John C.; Sperling, Reisa A.; Aisen, Paul S.; Roses, Allen D.; Welsh-Bohmer, Kathleen A.; Carrillo, Maria C.; Weninger, Stacie

    2016-01-01

    If we are to find treatments to postpone, reduce the risk of, or completely prevent the clinical onset of Alzheimer disease (AD), we need faster methods to evaluate promising preclinical AD treatments, new ways to work together in support of common goals, and a determination to expedite the initiation and performance of preclinical AD trials. In this article, we note some of the current challenges, opportunities and emerging strategies in preclinical AD treatment. We describe the Collaboration for Alzheimer’s Prevention (CAP)—a convening, harmonizing and consensus-building initiative to help stakeholders advance AD prevention research with rigour, care and maximal impact—and we demonstrate the impact of CAP on the goals and design of new preclinical AD trials. PMID:26416539

  17. Rigor or mortis: best practices for preclinical research in neuroscience.

    PubMed

    Steward, Oswald; Balice-Gordon, Rita

    2014-11-05

    Numerous recent reports document a lack of reproducibility of preclinical studies, raising concerns about potential lack of rigor. Examples of lack of rigor have been extensively documented and proposals for practices to improve rigor are appearing. Here, we discuss some of the details and implications of previously proposed best practices and consider some new ones, focusing on preclinical studies relevant to human neurological and psychiatric disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Preclinical evaluations of norcantharidin-loaded intravenous lipid microspheres with low toxicity.

    PubMed

    Lin, Xia; Zhang, Bo; Zhang, Keru; Zhang, Yu; Wang, Juan; Qi, Na; Yang, Shenshen; He, Haibing; Tang, Xing

    2012-12-01

    The aim of this study was to perform a systematic preclinical evaluation of norcantharidin (NCTD)-loaded intravenous lipid microspheres (NLM). Pharmacokinetics, biodistribution, antitumor efficacy and drug safety assessment (including acute toxicity, subchronic toxicity, hemolysis testing, intravenous stimulation and injection anaphylaxis) of NLM were carried out in comparison with the commercial product disodium norcantharidate injection (NI). The pharmacokinetics of NLM in rats was similar to that of NI, and a non-linear correlation was observed between AUC and dose. A comparable antitumor efficacy of NLM and NI was observed in mice inoculated with A549, BEL7402 and BCAP-37 cell lines. It was worth noting that the NLM produced a lower drug concentration in heart compared with NI, and significantly reduced the cardiac and renal toxicity. The LD(50) of NLM was twice higher than that of NI. In NLM, over 80% of NCTD was loaded in the lipid phase or bound with phospholipids. Thus, NCTD was sequestered by direct contacting with body fluids and largely avoided distribution into tissues, consequently leading to significantly reduced cardiac and renal toxicity. These preclinical results suggested that NLM could be a useful potential carrier for parenteral administration of NCTD, while providing a superior safety profile.

  19. Prenatal Antidepressant Exposure: Clinical and Preclinical Findings

    PubMed Central

    Bourke, Chase H.; Stowe, Zachary N.

    2014-01-01

    Pharmacological treatment of any maternal illness during pregnancy warrants consideration of the consequences of the illness and/or medication for both the mother and unborn child. In the case of major depressive disorder, which affects up to 10–20% of pregnant women, the deleterious effects of untreated depression on the offspring can be profound and long lasting. Progress has been made in our understanding of the mechanism(s) of action of antidepressants, fetal exposure to these medications, and serotonin’s role in development. New technologies and careful study designs have enabled the accurate sampling of maternal serum, breast milk, umbilical cord serum, and infant serum psychotropic medication concentrations to characterize the magnitude of placental transfer and exposure through human breast milk. Despite this progress, the extant clinical literature is largely composed of case series, population-based patient registry data that are reliant on nonobjective means and retrospective recall to determine both medication and maternal depression exposure, and limited inclusion of suitable control groups for maternal depression. Conclusions drawn from such studies often fail to incorporate embryology/neurotransmitter ontogeny, appropriate gestational windows, or a critical discussion of statistically versus clinically significant. Similarly, preclinical studies have predominantly relied on dosing models, leading to exposures that may not be clinically relevant. The elucidation of a defined teratological effect or mechanism, if any, has yet to be conclusively demonstrated. The extant literature indicates that, in many cases, the benefits of antidepressant use during pregnancy for a depressed pregnant woman may outweigh potential risks. PMID:24567054

  20. Mice deficient in ribosomal protein S6 phosphorylation suffer from muscle weakness that reflects a growth defect and energy deficit.

    PubMed

    Ruvinsky, Igor; Katz, Maximiliano; Dreazen, Avigail; Gielchinsky, Yuval; Saada, Ann; Freedman, Nanette; Mishani, Eyal; Zimmerman, Gabriel; Kasir, Judith; Meyuhas, Oded

    2009-05-19

    Mice, whose ribosomal protein S6 cannot be phosphorylated due to replacement of all five phosphorylatable serine residues by alanines (rpS6(P-/-)), are viable and fertile. However, phenotypic characterization of these mice and embryo fibroblasts derived from them, has established the role of these modifications in the regulation of the size of several cell types, as well as pancreatic beta-cell function and glucose homeostasis. A relatively passive behavior of these mice has raised the possibility that they suffer from muscle weakness, which has, indeed, been confirmed by a variety of physical performance tests. A large variety of experimental methodologies, including morphometric measurements of histological preparations, high throughput proteomic analysis, positron emission tomography (PET) and numerous biochemical assays, were used in an attempt to establish the mechanism underlying the relative weakness of rpS6(P-/-) muscles. Collectively, these experiments have demonstrated that the physical inferiority appears to result from two defects: a) a decrease in total muscle mass that reflects impaired growth, rather than aberrant differentiation of myofibers, as well as a diminished abundance of contractile proteins; and b) a reduced content of ATP and phosphocreatine, two readily available energy sources. The abundance of three mitochondrial proteins has been shown to diminish in the knockin mouse. However, the apparent energy deficiency in this genotype does not result from a lower mitochondrial mass or compromised activity of enzymes of the oxidative phosphorylation, nor does it reflect a decline in insulin-dependent glucose uptake, or diminution in storage of glycogen or triacylglycerol (TG) in the muscle. This study establishes rpS6 phosphorylation as a determinant of muscle strength through its role in regulation of myofiber growth and energy content. Interestingly, a similar role has been assigned for ribosomal protein S6 kinase 1, even though it regulates

  1. FXR blocks the growth of liver cancer cells through inhibiting mTOR-s6K pathway

    SciTech Connect

    Huang, Xiongfei, E-mail: xiongfeihuang@hotmail.com; Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou 350108, Fujian; Zeng, Yeting

    The nuclear receptor Farnesoid X Receptor (FXR) is likely a tumor suppressor in liver tissue but its molecular mechanism of suppression is not well understood. In this study, the gene expression profile of human liver cancer cells was investigated by microarray. Bioinformatics analysis of these data revealed that FXR might regulate the mTOR/S6K signaling pathway. This was confirmed by altering the expression level of FXR in liver cancer cells. Overexpression of FXR prevented the growth of cells and induced cell cycle arrest, which was enhanced by the mTOR/S6K inhibitor rapamycin. FXR upregulation also intensified the inhibition of cell growth bymore » rapamycin. Downregulation of FXR produced the opposite effect. Finally, we found that ectopic expression of FXR in SK-Hep-1 xenografts inhibits tumor growth and reduces expression of the phosphorylated protein S6K. Taken together, our data provide the first evidence that FXR suppresses proliferation of human liver cancer cells via the inhibition of the mTOR/S6K signaling pathway. FXR expression can be used as a biomarker of personalized mTOR inhibitor treatment assessment for liver cancer patients. -- Highlights: •FXR inhibits the proliferation of liver cancer cells by prolonging G0/G1 phase. •Microarray results indicate that mTOR-S6k signaling is involved in cellular processes in which FXR plays an important role. •FXR blocks the growth of liver cancer cells via the inhibition of the mTOR/S6K signaling pathway in vitro and in vivo.« less

  2. Preclinical evaluation of implantable cardioverter-defibrillator developed for magnetic resonance imaging use.

    PubMed

    Gold, Michael R; Kanal, Emanuel; Schwitter, Juerg; Sommer, Torsten; Yoon, Hyun; Ellingson, Michael; Landborg, Lynn; Bratten, Tara

    2015-03-01

    Many patients with an implantable cardioverter-defibrillator (ICD) have indications for magnetic resonance imaging (MRI). However, MRI is generally contraindicated in ICD patients because of potential risks from hazardous interactions between the MRI and ICD system. The purpose of this study was to use preclinical computer modeling, animal studies, and bench and scanner testing to demonstrate the safety of an ICD system developed for 1.5-T whole-body MRI. MRI hazards were assessed and mitigated using multiple approaches: design decisions to increase safety and reliability, modeling and simulation to quantify clinical MRI exposure levels, animal studies to quantify the physiologic effects of MRI exposure, and bench testing to evaluate safety margin. Modeling estimated the incidence of a chronic change in pacing capture threshold >0.5 V and 1.0 V to be less than 1 in 160,000 and less than 1 in 1,000,000 cases, respectively. Modeling also estimated the incidence of unintended cardiac stimulation to occur in less than 1 in 1,000,000 cases. Animal studies demonstrated no delay in ventricular fibrillation detection and no reduction in ventricular fibrillation amplitude at clinical MRI exposure levels, even with multiple exposures. Bench and scanner testing demonstrated performance and safety against all other MRI-induced hazards. A preclinical strategy that includes comprehensive computer modeling, animal studies, and bench and scanner testing predicts that an ICD system developed for the magnetic resonance environment is safe and poses very low risks when exposed to 1.5-T normal operating mode whole-body MRI. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  3. Drosophila homolog of the human S6 ribosomal protein is required for tumor suppression in the hematopoietic system.

    PubMed Central

    Watson, K L; Konrad, K D; Woods, D F; Bryant, P J

    1992-01-01

    The tumor suppressor gene lethal(1)aberrant immune response 8 (air8) of Drosophila melanogaster encodes a homolog of the human S6 ribosomal protein. P element insertions that prevent expression of this gene cause overgrowth of the lymph glands (the hematopoietic organs), abnormal blood cell differentiation, and melanotic tumor formation. They also cause delayed development, inhibit growth of most of the larval organs, and lead to larval lethality. Mitotic recombination experiments indicate that the normal S6 gene is required for clone survival in the germ line and imaginal discs. The S6 gene produces a 1.1-kilobase transcript that is abundant throughout development in wild-type animals and in revertants derived from the insertional mutants but is barely detectable in the mutant larvae. cDNAs corresponding to this transcript show a 248-amino acid open reading frame with 75.4% identity and 94.8% similarity to both human and rat S6 ribosomal protein sequences. The results reveal a regulatory function of this ribosomal protein in the hematopoietic system of Drosophila that may be related to its developmentally regulated phosphorylation. Images PMID:1454811

  4. Synthesis, Crystal Structure, and Physical Properties of New Layered Oxychalcogenide La2O2Bi3AgS6

    NASA Astrophysics Data System (ADS)

    Hijikata, Yudai; Abe, Tomohiro; Moriyoshi, Chikako; Kuroiwa, Yoshihiro; Goto, Yosuke; Miura, Akira; Tadanaga, Kiyoharu; Wang, Yongming; Miura, Osuke; Mizuguchi, Yoshikazu

    2017-12-01

    We have synthesized a new layered oxychalcogenide La2O2Bi3AgS6. From synchrotron X-ray diffraction and Rietveld refinement, the crystal structure of La2O2Bi3AgS6 was refined using a model of the P4/nmm space group with a = 4.0644(1) Å and c = 19.412(1) Å, which is similar to the related compound LaOBiPbS3, while the interlayer bonds (M2-S1 bonds) are apparently shorter in La2O2Bi3AgS6. The tunneling electron microscopy (TEM) image confirmed the lattice constant derived from Rietveld refinement (c ˜ 20 Å). The electrical resistivity and Seebeck coefficient suggested that the electronic states of La2O2Bi3AgS6 are more metallic than those of LaOBiS2 and LaOBiPbS3. The insertion of a rock-salt-type chalcogenide into the van der Waals gap of BiS2-based layered compounds, such as LaOBiS2, will be a useful strategy for designing new layered functional materials in the layered chalcogenide family.

  5. Photorefractive splicing device with double phase conjugate mirror using Sn2P2S6:Sb crystal

    NASA Astrophysics Data System (ADS)

    Wakayama, Yuta; Okamoto, Atsushi; Shimayabu, Kohei; Kojima, Yasunori; Grabar, Alexander A.

    2009-02-01

    We develop a splicing device for photonic crystal fibers (PCFs) based on a double phase conjugate mirror (DPCM) using a novel photorefractive (PR) Sn2P2S6:Sb 1.5% crystal. This PR splicer has many attractive characteristics including modal field compensation and the automatic reconfiguration of the optical path. Utilizing a DPCM as the splicer, our device can adapt to misalignments automatically since the incident beams continuously rewrite an index grating which formed in the crystal. By the implementation of the Sn2P2S6:Sb crystal, the response time for the characteristic of dynamic reconfiguration is improved several-hundred-fold compared with conventional materials, e.g. BaTiO3. We demonstrate that the high angular tolerance is provided using the DPCM with the Sn2P2S6:Sb crystal. When the misalignment of the incident angle is from -7° to 8°, the increment of coupling loss is less than 0.6dB. This is several-ten-fold compared with the fusion splicing. We reveal the dependence of the coupling loss on the position of the incident beams and also the dependence of the energy flow on the propagation distance for the first time with the two-dimensional finite-difference beampropagation method. Using our numerical simulation tool, we can visually investigate the beam propagation property considering the influence of the fanning effect in the Sn2P2S6 crystals.

  6. Genetic removal of p70 S6 kinase 1 corrects molecular, synaptic, and behavioral phenotypes in fragile X syndrome mice.

    PubMed

    Bhattacharya, Aditi; Kaphzan, Hanoch; Alvarez-Dieppa, Amanda C; Murphy, Jaclyn P; Pierre, Philippe; Klann, Eric

    2012-10-18

    Fragile X syndrome (FXS) is the leading inherited cause of autism and intellectual disability. Aberrant synaptic translation has been implicated in the etiology of FXS, but most lines of research on therapeutic strategies have targeted protein synthesis indirectly, far upstream of the translation machinery. We sought to perturb p70 ribosomal S6 kinase 1 (S6K1), a key translation initiation and elongation regulator, in FXS model mice. We found that genetic reduction of S6K1 prevented elevated phosphorylation of translational control molecules, exaggerated protein synthesis, enhanced mGluR-dependent long-term depression (LTD), weight gain, and macro-orchidism in FXS model mice. In addition, S6K1 deletion prevented immature dendritic spine morphology and multiple behavioral phenotypes, including social interaction deficits, impaired novel object recognition, and behavioral inflexibility. Our results support the model that dysregulated protein synthesis is the key causal factor in FXS and that restoration of normal translation can stabilize peripheral and neurological function in FXS. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Use of Statins to Augment Progenitor Cell Function in Preclinical and Clinical Studies of Regenerative Therapy: a Systematic Review.

    PubMed

    Park, Angela; Barrera-Ramirez, Juliana; Ranasinghe, Indee; Pilon, Sophie; Sy, Richmond; Fergusson, Dean; Allan, David S

    2016-06-01

    Mesenchymal stromal cells (MSCs) and endothelial progenitor cells (EPCs) are used in cell-based regenerative therapy. HMG CoA reductase inhibitors (statins) appear promising in blocking apoptosis, prolonging progenitor cell survival and improving their capacity to repair organ function. We performed a systematic review of preclinical and clinical studies to clarify whether statins can improve cell-based repair of organ injury. MEDLINE, EMBASE, and PUBMED databases were searched (1947 to June 25, 2013). Controlled clinical and pre-clinical studies were included that evaluated statin therapy used alone or in combination with MSCs or EPCs in patients or animals with organ injury. After screening 771 citations, 100 records underwent full eligibility screening of which 38 studies met eligibility and were included in the review: Studies were grouped into pre-clinical studies that involved statin treatment in combination with cell therapy (18 studies), preclinical studies of statin therapy alone (13 studies) and clinical studies of statin therapy (7 studies). Studies addressed cardiac injury (14 studies), vascular disorders (15 studies), neurologic conditions (8 studies) and bone fractures (1 study). Pre-clinical studies of statins in combination with MSC infusion (15 studies) or EPC therapy (3 studies) were described and despite marked heterogeneity in reporting outcomes of cellular analysis and organ function, all of these cell-based pre-clinical studies reported improved organ recovery with the addition of statin therapy. Moreover, 13 pre-clinical studies involved the administration of a statin drug alone to animals. An increase in EPC number and/or function (no studies of MSCs) was reported in 11 of these studies (85 %) and improved organ function in 12 studies (92 %). We also identified 7 clinical studies and none involved the administration of cells but described an increased number and/or function of EPCs (no studies of MSCs) and improved organ function with

  8. Considering sex as a biological variable in preclinical research.

    PubMed

    Miller, Leah R; Marks, Cheryl; Becker, Jill B; Hurn, Patricia D; Chen, Wei-Jung; Woodruff, Teresa; McCarthy, Margaret M; Sohrabji, Farida; Schiebinger, Londa; Wetherington, Cora Lee; Makris, Susan; Arnold, Arthur P; Einstein, Gillian; Miller, Virginia M; Sandberg, Kathryn; Maier, Susan; Cornelison, Terri L; Clayton, Janine A

    2017-01-01

    In June 2015, the National Institutes of Health (NIH) released a Guide notice (NOT-OD-15-102) that highlighted the expectation of the NIH that the possible role of sex as a biologic variable be factored into research design, analyses, and reporting of vertebrate animal and human studies. Anticipating these guidelines, the NIH Office of Research on Women's Health, in October 2014, convened key stakeholders to discuss methods and techniques for integrating sex as a biologic variable in preclinical research. The workshop focused on practical methods, experimental design, and approaches to statistical analyses in the use of both male and female animals, cells, and tissues in preclinical research. Workshop participants also considered gender as a modifier of biology. This article builds on the workshop and is meant as a guide to preclinical investigators as they consider methods and techniques for inclusion of both sexes in preclinical research and is not intended to prescribe exhaustive/specific approaches for compliance with the new NIH policy.-Miller, L. R., Marks, C., Becker, J. B., Hurn, P. D., Chen, W.-J., Woodruff, T., McCarthy, M. M., Sohrabji, F., Schiebinger, L., Wetherington, C. L., Makris, S., Arnold, A. P., Einstein, G., Miller, V. M., Sandberg, K., Maier, S., Cornelison, T. L., Clayton, J. A. Considering sex as a biological variable in preclinical research. © FASEB.

  9. Challenges for Preclinical Investigations of Human Biofield Modalities

    PubMed Central

    Gronowicz, Gloria; Bengston, William

    2015-01-01

    Preclinical models for studying the effects of the human biofield have great potential to advance our understanding of human biofield modalities, which include external qigong, Johrei, Reiki, therapeutic touch, healing touch, polarity therapy, pranic healing, and other practices. A short history of Western biofield studies using preclinical models is presented and demonstrates numerous and consistent examples of human biofields significantly affecting biological systems both in vitro and in vivo. Methodological issues arising from these studies and practical solutions in experimental design are presented. Important questions still left unanswered with preclinical models include variable reproducibility, dosing, intentionality of the practitioner, best preclinical systems, and mechanisms. Input from the biofield practitioners in the experimental design is critical to improving experimental outcomes; however, the development of standard criteria for uniformity of practice and for inclusion of multiple practitioners is needed. Research in human biofield studies involving preclinical models promises a better understanding of the mechanisms underlying the efficacy of biofield therapies and will be important in guiding clinical protocols and integrating treatments with conventional medical therapies. PMID:26665042

  10. Neuropsychiatric symptoms predict hypometabolism in preclinical Alzheimer disease.

    PubMed

    Ng, Kok Pin; Pascoal, Tharick A; Mathotaarachchi, Sulantha; Chung, Chang-Oh; Benedet, Andréa L; Shin, Monica; Kang, Min Su; Li, Xiaofeng; Ba, Maowen; Kandiah, Nagaendran; Rosa-Neto, Pedro; Gauthier, Serge

    2017-05-09

    To identify regional brain metabolic dysfunctions associated with neuropsychiatric symptoms (NPS) in preclinical Alzheimer disease (AD). We stratified 115 cognitively normal individuals into preclinical AD (both amyloid and tau pathologies present), asymptomatic at risk for AD (either amyloid or tau pathology present), or healthy controls (no amyloid or tau pathology present) using [ 18 F]florbetapir PET and CSF phosphorylated tau biomarkers. Regression and voxel-based regression models evaluated the relationships between baseline NPS measured by the Neuropsychiatric Inventory (NPI) and baseline and 2-year change in metabolism measured by [ 18 F]fluorodeoxyglucose (FDG) PET. Individuals with preclinical AD with higher NPI scores had higher [ 18 F]FDG uptake in the posterior cingulate cortex (PCC), ventromedial prefrontal cortex, and right anterior insula at baseline. High NPI scores predicted subsequent hypometabolism in the PCC over 2 years only in individuals with preclinical AD. Sleep/nighttime behavior disorders and irritability and lability were the components of the NPI that drove this metabolic dysfunction. The magnitude of NPS in preclinical cases, driven by sleep behavior and irritability domains, is linked to transitory metabolic dysfunctions within limbic networks vulnerable to the AD process and predicts subsequent PCC hypometabolism. These findings support an emerging conceptual framework in which NPS constitute an early clinical manifestation of AD pathophysiology. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

  11. Curriculum content and assessment of pre-clinical dental skills: A survey of undergraduate dental education in Europe.

    PubMed

    Field, J; Stone, S; Orsini, C; Hussain, A; Vital, S; Crothers, A; Walmsley, D

    2018-05-01

    Since 1981, the qualifications for various healthcare professionals across the European Union have enjoyed mutual recognition in accordance with the EU Directive 81/1057/EEC. Whilst the directive includes dental practitioners, it is recognised that significant variation exists in curriculum structure, content and scope of practice across institutions. This article aimed to explore pan-European practice in relation to curriculum content, teaching and learning strategies and assessment of pre-clinical dental skills. A request to complete an online questionnaire, in English, was sent electronically to skills leads at all Association of Dental Education in Europe member schools. The questionnaire collected information in relation to institution and country, regulatory requirements to demonstrate safety, details of specific pre-clinical skills courses, learning materials and teaching staff. Forty-eight institutions, from 25 European countries responded. Seven countries (n=7, 28%) reported no requirement to demonstrate student operative safety prior to patient treatment. Several core and operative clinical skills are common to the majority of institutions. The most commonly taught core skills related directly to the clinical environment such as cross-infection control and hand washing. The least common were skills that indirectly related to patient care, such as communication skills and working as a team. There are clear differences within European pre-clinical dental education, and greater efforts are needed to demonstrate that all European students are fit to practice before they start treating patients. Learning outcomes, teaching activities and assessment activities of pre-clinical skills should be shared collaboratively to further standardise curricula. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Preclinical evaluation of a Haemophilus influenzae type b conjugate vaccine process intended for technology transfer.

    PubMed

    Hamidi, Ahd; Verdijk, Pauline; Kreeftenberg, Hans

    2014-01-01

    Introduction of Haemophilus influenzae type b (Hib) vaccine in low- and middle-income countries has been limited by cost and availability of Hib conjugate vaccines for a long time. It was previously recognized by the Institute for Translational Vaccinology (Intravacc, originating from the former Vaccinology Unit of the National Institute of Public Health [RIVM] and the Netherlands Vaccine Institute [NVI]) that local production of a Hib conjugate vaccine would increase the affordability and sustainability of the vaccine and thereby help to speed up Hib introduction in these countries. A new affordable and a non-infringing production process for a Hib conjugate vaccine was developed, including relevant quality control tests, and the technology was transferred to a number of vaccine manufacturers in India, Indonesia, and China. As part of the Hib technology transfer project managed by Intravacc, a preclinical toxicity study was conducted in the Netherlands to test the safety and immunogenicity of this new Hib conjugate vaccine. The data generated by this study were used by the technology transfer partners to accelerate the clinical development of the new Hib conjugate vaccine. A repeated dose toxicity and local tolerance study in rats was performed to assess the reactogenicity and immunogenicity of a new Hib conjugate vaccine compared to a licensed vaccine. The results showed that the vaccine was well tolerated and immunogenic in rats, no major differences in both safety and immunogenicity in rats were found between the vaccine produced according to the production process developed by Intravacc and the licensed one. Rats may be useful to verify the immunogenicity of Hib conjugate vaccines and for preclinical evaluation. In general, nonclinical evaluation of the new Hib conjugate vaccine, including this proof of concept (safety and immunogenicity study in rats), made it possible for technology transfer partners, having implemented the original process with no changes

  13. Improved preclinical cardiovascular therapeutic indices with long-term inhibition of norepinephrine reuptake using reboxetine

    SciTech Connect

    Fossa, Anthony A., E-mail: anthony.fossa@icardiac.com; Wisialowski, Todd A.; Cremers, Thomas

    2012-11-01

    Norepinephrine reuptake inhibitors (NRIs) acutely increase norepinephrine (NE) levels, but therapeutic antidepressant activity is only observed after weeks of treatment because central NE levels progressively increase during continued drug exposure. Similarly, while NRIs acutely increase blood pressure (BP) and heart rate (HR) due to enhanced sympathetic neurotransmission, chronic treatment changes the responsiveness of the central noradrenergic system and suppresses these effects via autonomic regulation. To better understand the relationship between NE increases and cardiovascular safety, we investigated acute and chronic effects of the NRI reboxetine on central NE release and on BP and HR and electrical alternans, a measure ofmore » arrhythmia liability, in guinea pigs. NE release was assessed by microdialysis in medial prefrontal cortex (mPFC) and hypothalamic paraventricular nucleus (PVN); BP and HR were measured by telemetry. Animals were treated for 28 days with 15 mg/kg/day of reboxetine or vehicle via an osmotic minipump and then challenged with acute intravenous doses of reboxetine. Animals chronically treated with reboxetine had 2-fold higher extracellular basal NE levels in mPFC and PVN compared to basal levels after chronic vehicle treatment. BP was significantly increased after the first day of treatment, and gradually returned to vehicle levels by day 21. These data indicate that chronic NRI treatment may lead to an increase in central NE levels and a concomitant reduction in BP based on exposure–response curves compared to vehicle treatment, suggesting a larger separation between preclinical estimates of efficacy vs. safety compared to acute NRI treatment. -- Highlights: ► Acute RBX produces blood pressure increases acutely that decrease with chronic RBX ► Chronic RBX increases brain NE levels, a preclinical surrogate of improved efficacy ► Short-term screening of NRI often underestimates the chronic therapeutic index ► Chronic

  14. Characterization of novel preclinical dose distributions for micro irradiator

    NASA Astrophysics Data System (ADS)

    Kodra, J.; Miles, D.; Yoon, S. W.; Kirsch, D. G.; Oldham, M.

    2017-05-01

    This work explores and demonstrates the feasibility of utilizing new 3D printing techniques to implement advanced micro radiation therapy for pre-clinical small animal studies. 3D printed blocks and compensators were designed and printed from a strong x-ray attenuating material at sub-millimeter resolution. These techniques enable a powerful range of new preclinical treatment capabilities including grid therapy, lattice therapy, and IMRT treatment. At small scales, verification of these treatments is exceptionally challenging, and high resolution 3D dosimetry (0.5mm3) is an essential capability to characterize and verify these capabilities, Here, investigate the 2D and 3D dosimetry of several novel pre-clinical treatments using a combination of EBT film and Presage/optical-CT 3D dosimetry in rodent-morphic dosimeters.

  15. Saccharin Aza Bioisosteres-Synthesis and Preclinical Property Comparisons.

    PubMed

    Chen, Yantao; Aurell, Carl-Johan; Pettersen, Anna; Lewis, Richard J; Hayes, Martin A; Lepistö, Matti; Jonson, Anna C; Leek, Hanna; Thunberg, Linda

    2017-06-08

    Saccharin is a well-known scaffold in drug discovery. Herein, we report the synthesis and preclinical property comparisons of three bioisosteres of saccharin: aza-pseudosaccharins (cluster B ), and two new types of aza-saccharins (clusters C and D ). We demonstrate a convenient protocol to selectively synthesize products in cluster C or D when primary amines are used. Preclinical characterization of selected matched-pair products is reported. Through comparison of two diastereomers, we highlight how stereochemistry affects the preclinical properties. Given that saccharin-based derivatives are widely used in many chemistry fields, we foresee that structures exemplified by clusters C and D offer new opportunities for novel drug design, creating a chiral center on the sulfur atom and the option of substitution at two different nitrogens.

  16. Circulating Tumor Cell Analysis in Preclinical Mouse Models of Metastasis.

    PubMed

    Kitz, Jenna; Lowes, Lori E; Goodale, David; Allan, Alison L

    2018-04-28

    The majority of cancer deaths occur because of metastasis since current therapies are largely non-curative in the metastatic setting. The use of in vivo preclinical mouse models for assessing metastasis is, therefore, critical for developing effective new cancer biomarkers and therapies. Although a number of quantitative tools have been previously developed to study in vivo metastasis, the detection and quantification of rare metastatic events has remained challenging. This review will discuss the use of circulating tumor cell (CTC) analysis as an effective means of tracking and characterizing metastatic disease progression in preclinical mouse models of breast and prostate cancer and the resulting lessons learned about CTC and metastasis biology. We will also discuss how the use of clinically-relevant CTC technologies such as the CellSearch ® and Parsortix™ platforms for preclinical CTC studies can serve to enhance the study of cancer biology, new biomarkers, and novel therapies from the bench to the bedside.

  17. Insights from Preclinical Choice Models on Treating Drug Addiction.

    PubMed

    Banks, Matthew L; Negus, S Stevens

    2017-02-01

    Substance-use disorders are a global public health problem that arises from behavioral misallocation between drug use and more adaptive behaviors maintained by nondrug alternatives (e.g., food or money). Preclinical drug self-administration procedures that incorporate a concurrently available nondrug reinforcer (e.g., food) provide translationally relevant and distinct dependent measures of behavioral allocation (i.e., to assess the relative reinforcing efficacy of the drug) and behavioral rate (i.e., to assess motor competence). In particular, preclinical drug versus food 'choice' procedures have produced increasingly concordant results with both human laboratory drug self-administration studies and double-blind placebo-controlled clinical trials. Accordingly, here we provide a heuristic framework of substance-use disorders based on a behavioral-centric perspective and recent insights from these preclinical choice procedures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Non-invasive molecular imaging for preclinical cancer therapeutic development

    PubMed Central

    O'Farrell, AC; Shnyder, SD; Marston, G; Coletta, PL; Gill, JH

    2013-01-01

    Molecular and non-invasive imaging are rapidly emerging fields in preclinical cancer drug discovery. This is driven by the need to develop more efficacious and safer treatments, the advent of molecular-targeted therapeutics, and the requirements to reduce and refine current preclinical in vivo models. Such bioimaging strategies include MRI, PET, single positron emission computed tomography, ultrasound, and optical approaches such as bioluminescence and fluorescence imaging. These molecular imaging modalities have several advantages over traditional screening methods, not least the ability to quantitatively monitor pharmacodynamic changes at the cellular and molecular level in living animals non-invasively in real time. This review aims to provide an overview of non-invasive molecular imaging techniques, highlighting the strengths, limitations and versatility of these approaches in preclinical cancer drug discovery and development. PMID:23488622

  19. Insights from Preclinical Choice Models on Treating Drug Addiction

    PubMed Central

    Banks, Matthew L.; Negus, S. Stevens

    2016-01-01

    Substance-use disorders are a global public health problem that arises from behavioral misallocation between drug use and more adaptive behaviors maintained by nondrug alternatives (e.g., food or money). Preclinical drug self-administration procedures that incorporate a concurrently available nondrug reinforcer (e.g., food) provide translationally relevant and distinct dependent measures of behavioral allocation (i.e., to assess the relative reinforcing efficacy of the drug) and behavioral rate (i.e., to assess motor competence). In particular, preclinical drug versus food ‘choice’ procedures have produced increasingly concordant results with both human laboratory drug self-administration studies and double-blind placebo-controlled clinical trials. Accordingly, here we provide a heuristic framework of substance-use disorders based on a behavioral-centric perspective and recent insights from these preclinical choice procedures. PMID:27916279

  20. Stakeholders' Perspectives on Preclinical Testing for Alzheimer's Disease.

    PubMed

    Arias, Jalayne J; Cummings, Jeffrey; Grant, Alexander Rae; Ford, Paul J

    2015-01-01

    Progress towards validating amyloid beta as an early indicator of Alzheimer's disease (AD) heightens the need for evaluation of stakeholders' perspectives of the benefits and harms of preclinical testing in asymptomatic individuals. Investigators conducted and analyzed 14 semi-structured interviews with family members of patients diagnosed with AD. Participants reported benefits, including the potential to seek treatment, make lifestyle changes, and prepare for cognitive impairment. Participants identified harms, including social harms, adverse life decisions, and psychological harms. Nine participants reported either a "positive global perspective" or a "positive global perspective (qualified)." Results from this study characterized stakeholders' perspectives on the potential benefits and harms of clinical use of preclinical testing for AD. Investigators used data from this study to develop a framework that contributes to ongoing discussions that will evaluate widespread adoption of preclinical testing and will inform future research. Copyright 2015 The Journal of Clinical Ethics. All rights reserved.

  1. A laboratory silicone for preclinical training in ear prosthesis.

    PubMed

    Anand, Vijay; Haribabu; Vimala; Gnanasamband, Vimala

    2013-07-01

    This article describes an industrial elastic silicone as a material for the laboratory fabrication of ear prosthesis. It has been tested for toxicity in lab animals by the SGS India Pvt. Ltd and approved as a material to pass the parameter of abnormal toxicity. This material therefore can be safely recommended for laboratory exercise to fabricate facial prosthesis. The high cost of the maxillo facial silicone materials prohibits their use for facial prosthesis in pre-clinical training of post-graduate students in maxillofacial prosthodontics. For this reason, pre-clinical laboratory exercise in facial prosthesis is inadequate. A few institutions use polymethyl methacrylate resins which are rigid and do not have elastic characteristics of silicone, which is used for facial defects. This cost-effective industrial silicone material which mimics the elastic and color characteristics of the conventional silicones can be recommended for preclinical exercises.

  2. Metabolomics in Toxicology and Preclinical Research

    PubMed Central

    Ramirez, Tzutzuy; Daneshian, Mardas; Kamp, Hennicke; Bois, Frederic Y.; Clench, Malcolm R.; Coen, Muireann; Donley, Beth; Fischer, Steven M.; Ekman, Drew R.; Fabian, Eric; Guillou, Claude; Heuer, Joachim; Hogberg, Helena T.; Jungnickel, Harald; Keun, Hector C.; Krennrich, Gerhard; Krupp, Eckart; Luch, Andreas; Noor, Fozia; Peter, Erik; Riefke, Bjoern; Seymour, Mark; Skinner, Nigel; Smirnova, Lena; Verheij, Elwin; Wagner, Silvia; Hartung, Thomas; van Ravenzwaay, Bennard; Leist, Marcel

    2013-01-01

    Summary Metabolomics, the comprehensive analysis of metabolites in a biological system, provides detailed information about the biochemical/physiological status of a biological system, and about the changes caused by chemicals. Metabolomics analysis is used in many fields, ranging from the analysis of the physiological status of genetically modified organisms in safety science to the evaluation of human health conditions. In toxicology, metabolomics is the -omics discipline that is most closely related to classical knowledge of disturbed biochemical pathways. It allows rapid identification of the potential targets of a hazardous compound. It can give information on target organs and often can help to improve our understanding regarding the mode-of-action of a given compound. Such insights aid the discovery of biomarkers that either indicate pathophysiological conditions or help the monitoring of the efficacy of drug therapies. The first toxicological applications of metabolomics were for mechanistic research, but different ways to use the technology in a regulatory context are being explored. Ideally, further progress in that direction will position the metabolomics approach to address the challenges of toxicology of the 21st century. To address these issues, scientists from academia, industry, and regulatory bodies came together in a workshop to discuss the current status of applied metabolomics and its potential in the safety assessment of compounds. We report here on the conclusions of three working groups addressing questions regarding 1) metabolomics for in vitro studies 2) the appropriate use of metabolomics in systems toxicology, and 3) use of metabolomics in a regulatory context. PMID:23665807

  3. Quality Assurance in Biobanking for Pre-Clinical Research

    PubMed Central

    Simeon-Dubach, Daniel; Zeisberger, Steffen M.; Hoerstrup, Simon P.

    2016-01-01

    It is estimated that not less than USD 28 billion are spent each year in the USA alone on irreproducible pre-clinical research, which is not only a fundamental loss of investment and resources but also a strong inhibitor of efficiency for upstream processes regarding the translation towards clinical applications and therapies. The issues and cost of irreproducibility has mainly been published on pre-clinical research. In contrast to pre-clinical research, test material is often being transferred into humans in clinical research. To protect treated human subjects and guarantee a defined quality standard in the field of clinical research, the manufacturing and processing infrastructures have to strictly follow and adhere to certain (inter-)national quality standards. It is assumed and suggested by the authors that by an implementation of certain quality standards within the area of pre-clinical research, billions of USD might be saved and the translation phase of promising pre-clinical results towards clinical applications may substantially be improved. In this review, we discuss how an implementation of a quality assurance (QA) management system might positively improve sample quality and sustainability within pre-clinically focused biobank infrastructures. Biobanks are frequently positioned at the very beginning of the biomedical research value chain, and, since almost every research material has been stored in a biobank during the investigated life cycle, biobanking seems to be of substantial importance from this perspective. The role model of a QA-regulated biobank structure can be found in biobanks within the context of clinical research organizations such as in regenerative medicine clusters. PMID:27781023

  4. Nuclear safety

    NASA Technical Reports Server (NTRS)

    Buden, D.

    1991-01-01

    Topics dealing with nuclear safety are addressed which include the following: general safety requirements; safety design requirements; terrestrial safety; SP-100 Flight System key safety requirements; potential mission accidents and hazards; key safety features; ground operations; launch operations; flight operations; disposal; safety concerns; licensing; the nuclear engine for rocket vehicle application (NERVA) design philosophy; the NERVA flight safety program; and the NERVA safety plan.

  5. A phase III, randomized, double-blind, matched-pairs, active-controlled clinical trial and preclinical animal study to compare the durability, efficacy and safety between polynucleotide filler and hyaluronic acid filler in the correction of crow's feet: a new concept of regenerative filler.

    PubMed

    Pak, Chang Sik; Lee, Jongho; Lee, Hobin; Jeong, Jaehoon; Kim, Eun-Hee; Jeong, Jinwook; Choi, Hyeyeon; Kim, Byunghwi; Oh, Sujin; Kim, Iksoo; Heo, Chan Yeong

    2014-11-01

    The Rejuran® is a new filler product made from purified polynucleotides. Here we present data from an animal study and a clinical trial to examine the durability, efficacy and safety of the Rejuran® on crow's feet. For the animal study, 25 mice were divided into three groups: Group 1 received phosphate buffered saline (PBS); Group 2 were treated with Yvoire®; and Group 3 were treated with Rejuran®. The durability and efficacy of each treatment were assessed by microscopy and staining. In the clinical trial, 72 patients were randomized to receive Rejuran® treatment for crow's feet on one side and Yvoire-Hydro® on the contralateral side, at a ratio of 1:1. Repeated treatments were performed every two weeks for a total of three times, over a total of 12 weeks' observation. All injections and observations of efficacy and safety were performed by the same two investigators. In the animal study, the Rejuran® group showed similar durability and inflammatory response to the Yvoire® group. Upon efficacy assessment, the Rejuran® group showed the greatest elasticity and collagen composition, and a significant difference in skin surface roughness and wrinkle depth. In the clinical trial, the primary and secondary objective efficacy outcome measure showed no statistical significance between the two groups, and in safety outcomes there were no unexpected adverse effects. Our data suggest that the Rejuran®, as a new regenerative filler, can be useful to reduce wrinkles, by showing evidence for its efficacy and safety.

  6. Local Structural Investigations, Defect Formation, and Ionic Conductivity of the Lithium Ionic Conductor Li 4 P 2 S 6

    SciTech Connect

    Dietrich, Christian; Sadowski, Marcel; Sicolo, Sabrina

    Glassy, glass–ceramic, and crystalline lithium thiophosphates have attracted interest in their use as solid electrolytes in all-solid-state batteries. Despite similar structural motifs, including PS 4 3–, P 2S 6 4–, and P 2S 7 4– polyhedra, these materials exhibit a wide range of possible compositions, crystal structures, and ionic conductivities. Here, we present a combined approach of Bragg diffraction, pair distribution function analysis, Raman spectroscopy, and 31P magic angle spinning nuclear magnetic resonance spectroscopy to study the underlying crystal structure of Li 4P 2S 6. In this work, we show that the material crystallizes in a planar structural arrangement asmore » a glass ceramic composite, explaining the observed relatively low ionic conductivity, depending on the fraction of glass content. Calculations based on density functional theory provide an understanding of occurring diffusion pathways and ionic conductivity of this Li + ionic conductor.« less

  7. Arsenite induces cell transformation by reactive oxygen species, AKT, ERK1/2, and p70S6K1

    SciTech Connect

    Carpenter, Richard L.; Jiang, Yue; Jing, Yi

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer Chronic exposure to arsenite induces cell proliferation and transformation. Black-Right-Pointing-Pointer Arsenite-induced transformation increases ROS production and downstream signalings. Black-Right-Pointing-Pointer Inhibition of ROS levels via catalase reduces arsenite-induced cell transformation. Black-Right-Pointing-Pointer Interruption of AKT, ERK, or p70S6K1 inhibits arsenite-induced cell transformation. -- Abstract: Arsenic is naturally occurring element that exists in both organic and inorganic formulations. The inorganic form arsenite has a positive association with development of multiple cancer types. There are significant populations throughout the world with high exposure to arsenite via drinking water. Thus, human exposure to arsenic has become a significant public health problem. Recent evidencemore » suggests that reactive oxygen species (ROS) mediate multiple changes to cell behavior after acute arsenic exposure, including activation of proliferative signaling and angiogenesis. However, the role of ROS in mediating cell transformation by chronic arsenic exposure is unknown. We found that cells chronically exposed to sodium arsenite increased proliferation and gained anchorage-independent growth. This cell transformation phenotype required constitutive activation of AKT, ERK1/2, mTOR, and p70S6K1. We also observed these cells constitutively produce ROS, which was required for the constitutive activation of AKT, ERK1/2, mTOR, and p70S6K1. Suppression of ROS levels by forced expression of catalase also reduced cell proliferation and anchorage-independent growth. These results indicate cell transformation induced by chronic arsenic exposure is mediated by increased cellular levels of ROS, which mediates activation of AKT, ERK1/2, and p70S6K1.« less

  8. S6K links cell fate, cell cycle and nutrient response in C. elegans germline stem/progenitor cells

    PubMed Central

    Korta, Dorota Z.; Tuck, Simon; Hubbard, E. Jane Albert

    2012-01-01

    Coupling of stem/progenitor cell proliferation and differentiation to organismal physiological demands ensures the proper growth and homeostasis of tissues. However, in vivo mechanisms underlying this control are poorly characterized. We investigated the role of ribosomal protein S6 kinase (S6K) at the intersection of nutrition and the establishment of a stem/progenitor cell population using the C. elegans germ line as a model. We find that rsks-1 (which encodes the worm homolog of mammalian p70S6K) is required germline-autonomously for proper establishment of the germline progenitor pool. In the germ line, rsks-1 promotes cell cycle progression and inhibits larval progenitor differentiation, promotes growth of adult tumors and requires a conserved TOR phosphorylation site. Loss of rsks-1 and ife-1 (eIF4E) together reduces the germline progenitor pool more severely than either single mutant and similarly to reducing the activity of let-363 (TOR) or daf-15 (RAPTOR). Moreover, rsks-1 acts in parallel with the glp-1 (Notch) and daf-2 (insulin-IGF receptor) pathways, and does not share the same genetic dependencies with its role in lifespan control. We show that overall dietary restriction and amino acid deprivation cause germline defects similar to a subset of rsks-1 mutant phenotypes. Consistent with a link between diet and germline proliferation via rsks-1, loss of rsks-1 renders the germ line largely insensitive to the effects of dietary restriction. Our studies establish the C. elegans germ line as an in vivo model to understand TOR-S6K signaling in proliferation and differentiation and suggest that this pathway is a key nutrient-responsive regulator of germline progenitors. PMID:22278922

  9. Novel potato micro-tuber-inducing compound, (3R,6S)-6-hydroxylasiodiplodin, from a strain of Lasiodiplodia theobromae.

    PubMed

    Li, Peng; Takahashi, Kosaku; Matsuura, Hideyuki; Yoshihara, Teruhiko

    2005-08-01

    A novel potato micro-tuber-inducing compound was isolated from the culture broth of Lasiodiplodia theobromae Shimokita 2. The structure of the isolated compound was determined as (3R,6S)-6-hydroxylasiodiplodin by means of spectroscopic analyses, the modified Mosher method, and chemical conversion. The compound showed potato micro-tuber-inducing activity at a concentration of 10(-4) M, using the culture of single-node segments of potato stems in vitro.

  10. Preclinical Development of Cell-Based Products: a European Regulatory Science Perspective.

    PubMed

    McBlane, James W; Phul, Parvinder; Sharpe, Michaela

    2018-06-25

    This article describes preclinical development of cell-based medicinal products for European markets and discusses European regulatory mechanisms open to developers to aid successful product development. Cell-based medicinal products are diverse, including cells that are autologous or allogeneic, have been genetically modified, or not, or expanded ex vivo, and applied systemically or to an anatomical site different to that of their origin; comments applicable to one product may not be applicable to others, so bespoke development is needed, for all elements - quality, preclinical and clinical. After establishing how the product is produced, proof of potential for therapeutic efficacy, and then safety, of the product need to be determined. This includes understanding biodistribution, persistence and toxicity, including potential for malignant transformation. These elements need to be considered in the context of the intended clinical development. This article describes regulatory mechanisms available to developers to support product development that aim to resolve scientific issues prior to marketing authorization application, to enable patients to have faster access to the product than would otherwise be the case. Developers are encouraged to be aware of both the scientific issues and regulatory mechanisms to ensure patients can be supplied with these products.

  11. Viral factor TAV recruits TOR/S6K1 signalling to activate reinitiation after long ORF translation

    PubMed Central

    Schepetilnikov, Mikhail; Kobayashi, Kappei; Geldreich, Angèle; Caranta, Carole; Robaglia, Christophe; Keller, Mario; Ryabova, Lyubov A

    2011-01-01

    The protein kinase TOR (target-of-rapamycin) upregulates translation initiation in eukaryotes, but initiation restart after long ORF translation is restricted by largely unknown pathways. The plant viral reinitiation factor transactivator–viroplasmin (TAV) exceptionally promotes reinitiation through a mechanism involving retention on 80S and reuse of eIF3 and the host factor reinitiation-supporting protein (RISP) to regenerate reinitiation-competent ribosomal complexes. Here, we show that TAV function in reinitiation depends on physical association with TOR, with TAV–TOR binding being critical for both translation reinitiation and viral fitness. Consistently, TOR-deficient plants are resistant to viral infection. TAV triggers TOR hyperactivation and S6K1 phosphorylation in planta. When activated, TOR binds polyribosomes concomitantly with polysomal accumulation of eIF3 and RISP—a novel and specific target of TOR/S6K1—in a TAV-dependent manner, with RISP being phosphorylated. TAV mutants defective in TOR binding fail to recruit TOR, thereby abolishing RISP phosphorylation in polysomes and reinitiation. Thus, activation of reinitiation after long ORF translation is more complex than previously appreciated, with TOR/S6K1 upregulation being the key event in the formation of reinitiation-competent ribosomal complexes. PMID:21343906

  12. Proline Scan of the hERG Channel S6 Helix Reveals the Location of the Intracellular Pore Gate

    PubMed Central

    Thouta, Samrat; Sokolov, Stanislav; Abe, Yuki; Clark, Sheldon J.; Cheng, Yen M.; Claydon, Tom W.

    2014-01-01

    In Shaker-like channels, the activation gate is formed at the bundle crossing by the convergence of the inner S6 helices near a conserved proline-valine-proline motif, which introduces a kink that allows for electromechanical coupling with voltage sensor motions via the S4-S5 linker. Human ether-a-go-go-related gene (hERG) channels lack the proline-valine-proline motif and the location of the intracellular pore gate and how it is coupled to S4 movement is less clear. Here, we show that proline substitutions within the S6 of hERG perturbed pore gate closure, trapping channels in the open state. Performing a proline scan of the inner S6 helix, from Ile655 to Tyr667 revealed that gate perturbation occurred with proximal (I655P-Q664P), but not distal (R665P-Y667P) substitutions, suggesting that Gln664 marks the position of the intracellular gate in hERG channels. Using voltage-clamp fluorimetry and gating current analysis, we demonstrate that proline substitutions trap the activation gate open by disrupting the coupling between the voltage-sensing unit and the pore of the channel. We characterize voltage sensor movement in one such trapped-open mutant channel and demonstrate the kinetics of what we interpret to be intrinsic hERG voltage sensor movement. PMID:24606930

  13. Exploring the ϒ (4 S ,5 S ,6 S )→hb(1 P )η hidden-bottom hadronic transitions

    NASA Astrophysics Data System (ADS)

    Zhang, Yawei; Li, Gang

    2018-01-01

    Recently, the Belle Collaboration has reported the measurement of the spin-flipping transition ϒ (4 S )→hb(1 P )η with an unexpectedly large branching ratio: B (ϒ (4 S )→hb(1 P )η )=(2.18 ±0.11 ±0.18 )×10-3 . Such a large branching fraction contradicts with the anticipated suppression for the spin flip. In this work, we examine the effects induced by intermediate bottomed meson loops and point out that these effects are significantly important. Using the effective Lagrangian approach (ELA), we find the experimental data on ϒ (4 S )→hb(1 P )η can be accommodated with the reasonable inputs. We then explore the decays ϒ (5 S ,6 S )→hb(1 P )η and find that these two channels also have sizable branching fractions. We also calculate these processes in the framework of nonrelativistic effective field theory (NREFT). For the decays ϒ (4 S )→hb(1 P )η , the NREFT results are at the same order of magnitude but smaller than the ELA results by a factor of 2 to 5. For the decays ϒ (5 S ,6 S )→hb(1 P )η , the NREFT results are smaller than the ELA results by approximately 1 order of magnitude. We suggest a future experiment Belle-II to search for the ϒ (5 S ,6 S )→hb(1 P )η decays, which will be helpful for understanding the transition mechanism.

  14. Delicaflavone induces autophagic cell death in lung cancer via Akt/mTOR/p70S6K signaling pathway.

    PubMed

    Sui, Yuxia; Yao, Hong; Li, Shaoguang; Jin, Long; Shi, Peiying; Li, Zhijun; Wang, Gang; Lin, Shilan; Wu, Youjia; Li, Yuxiang; Huang, Liying; Liu, Qicai; Lin, Xinhua

    2017-03-01

    Searching for potential anticancer agents from natural sources is an effective strategy for developing novel chemotherapeutic agents. In this study, data supporting the in vitro and in vivo anticancer effects of delicaflavone, a rarely occurring biflavonoid from Selaginella doederleinii, were reported. Delicaflavone exhibited favorable anticancer properties, as shown by the MTT assay and xenograft model of human non-small cell lung cancer in male BALB/c nude mice without observable adverse effect. By transmission electron microscopy with acridine orange and Cyto-ID®Autophagy detection dyes, Western blot analysis, and RT-PCR assay, we confirmed that delicaflavone induces autophagic cell death by increasing the ratio of LC3-II to LC3-I, which are autophagy-related proteins, and promoting the generation of acidic vesicular organelles and autolysosomes in the cytoplasm of human lung cancer A549 and PC-9 cells in a time- and dose-dependent manner. Delicaflavone downregulated the expression of phospho-Akt, phospho-mTOR, and phospho-p70S6K in a time- and dose-dependent manner, suggesting that it induced autophagy by inhibiting the Akt/mTOR/p70S6K pathway in A549 and PC-9 cells. Delicaflavone is a potential anticancer agent that can induce autophagic cell death in human non-small cell lung cancer via the Akt/mTOR/p70S6K signaling pathway. Delicaflavone showed anti-lung cancer effects in vitro and in vivo. Delicaflavone induced autophagic cell death via Akt/mTOR/p70S6K signaling pathway. Delicaflavone did not show observable side effects in a xenograft mouse model. Delicaflavone may represent a potential therapeutic agent for lung cancer. Delicaflavone showed anti-lung cancer effects in vitro and in vivo. Delicaflavone induced autophagic cell death via Akt/mTOR/p70S6K signaling pathway. Delicaflavone did not show observable side effects in a xenograft mouse model. Delicaflavone may represent a potential therapeutic agent for lung cancer.

  15. Involvement of Heterogeneous Ribonucleoprotein F in the Regulation of Cell Proliferation via the Mammalian Target of Rapamycin/S6 Kinase 2 Pathway

    PubMed Central

    Goh, Eddy T. H.; Pardo, Olivier E.; Michael, Nicholas; Niewiarowski, Andrew; Totty, Nick; Volkova, Dariya; Tsaneva, Irina R.; Seckl, Michael J.; Gout, Ivan

    2010-01-01

    The S6 kinases (S6Ks) have been linked to a number of cellular processes, including translation, insulin metabolism, cell survival, and RNA splicing. Signaling via the phosphotidylinositol 3-kinase and mammalian target of rapamycin (mTOR) pathways is critical in regulating the activity and subcellular localization of S6Ks. To date, nuclear functions of both S6K isoforms, S6K1 and S6K2, are not well understood. To better understand S6K nuclear roles, we employed affinity purification of S6Ks from nuclear preparations followed by mass spectrometry analysis for the identification of novel binding partners. In this study, we report that in contrast to S6K1, the S6K2 isoform specifically associates with a number of RNA-binding proteins, including heterogeneous ribonucleoproteins (hnRNPs). We focused on studying the mechanism and physiological relevance of the S6K2 interaction with hnRNP F/H. Interestingly, the S6K2-hnRNP F/H interaction was not affected by mitogenic stimulation, whereas mTOR binding to hnRNP F/H was induced by serum stimulation. In addition, we define a new role of hnRNP F in driving cell proliferation, which could be partially attenuated by rapamycin treatment. S6K2-driven cell proliferation, on the other hand, could be blocked by small interfering RNA-mediated down-regulation of hnRNP F. These results demonstrate that the specific interaction between mTOR and S6K2 with hnRNPs is implicated in the regulation of cell proliferation. PMID:20308064

  16. Preclinical development of monoclonal antibodies: considerations for the use of non-human primates.

    PubMed

    Chapman, Kathryn; Pullen, Nick; Coney, Lee; Dempster, Maggie; Andrews, Laura; Bajramovic, Jeffrey; Baldrick, Paul; Buckley, Lorrene; Jacobs, Abby; Hale, Geoff; Green, Colin; Ragan, Ian; Robinson, Vicky

    2009-01-01

    The development of mAbs remains high on the therapeutic agenda for the majority of pharmaceutical and biotechnology companies. Often, the only relevant species for preclinical safety assessment of mAbs are non-human primates (NHPs), and this raises important scientific, ethical and economic issues. To investigate evidence-based opportunities to minimize the use of NHPs, an expert working group with representatives from leading pharmaceutical and biotechnology companies, contract research organizations and institutes from Europe and the USA, has shared and analyzed data on mAbs for a range of therapeutic areas. This information has been applied to hypothetical examples to recommend scientifically appropriate development pathways and study designs for a variety of potential mAbs. The addendum of ICHS6 provides a timely opportunity for the scientific and regulatory community to embrace strategies which minimize primate use and increase efficiency of mAb development.

  17. Increasing efficiency of preclinical research by group sequential designs

    PubMed Central

    Piper, Sophie K.; Rex, Andre; Florez-Vargas, Oscar; Karystianis, George; Schneider, Alice; Wellwood, Ian; Siegerink, Bob; Ioannidis, John P. A.; Kimmelman, Jonathan; Dirnagl, Ulrich

    2017-01-01

    Despite the potential benefits of sequential designs, studies evaluating treatments or experimental manipulations in preclinical experimental biomedicine almost exclusively use classical block designs. Our aim with this article is to bring the existing methodology of group sequential designs to the attention of researchers in the preclinical field and to clearly illustrate its potential utility. Group sequential designs can offer higher efficiency than traditional methods and are increasingly used in clinical trials. Using simulation of data, we demonstrate that group sequential designs have the potential to improve the efficiency of experimental studies, even when sample sizes are very small, as is currently prevalent in preclinical experimental biomedicine. When simulating data with a large effect size of d = 1 and a sample size of n = 18 per group, sequential frequentist analysis consumes in the long run only around 80% of the planned number of experimental units. In larger trials (n = 36 per group), additional stopping rules for futility lead to the saving of resources of up to 30% compared to block designs. We argue that these savings should be invested to increase sample sizes and hence power, since the currently underpowered experiments in preclinical biomedicine are a major threat to the value and predictiveness in this research domain. PMID:28282371

  18. Stress, Burnout and Coping Strategies in Preclinical Medical Students

    PubMed Central

    Fares, Jawad; Al Tabosh, Hayat; Saadeddin, Zein; El Mouhayyar, Christopher; Aridi, Hussam

    2016-01-01

    It is acknowledged that physicians do not seek the same expert aid for themselves as they would offer their patients. In their preclinical years, medical students appear to espouse comparable behavior. To many, medicine is described as a never-ending path that places the student under heavy stress and burnout from the beginning, leaving him/her vulnerable and with insufficient coping methods. Hence, the objective of this study is to 1) explore the prevalence of stress and burnout among preclinical medical students, and 2) propose solutions to decrease stress and burnout and improve medical education in the preclinical years. A detailed scholarly research strategy using Google Scholar, Scopus, Embase, MEDLINE and PubMed was implemented to highlight key themes that are relevant to preclinical medical students’ stress and burnout. Stress varied among different samples of medical students and ranged between 20.9% and 90%. Conversely, burnout ranged between 27% and 75%. Methods that help in reducing the incidence of stress and burnout by promoting strategies that focus on personal engagement, extracurricular activities, positive reinterpretation and expression of emotion, student-led mentorship programs, evaluation systems, career counseling and life coaching should be adopted. PMID:27042604

  19. Nanotechnology and nuclear medicine; research and preclinical applications.

    PubMed

    Assadi, Majid; Afrasiabi, Kolsoom; Nabipour, Iraj; Seyedabadi, Mohammad

    2011-01-01

    The birth of nanotechnology in human society was around 2000 years ago and soon found applications in various fields. In this article, we highlight the current status of research and preclinical applications and also future prospects of nanotechnology in medicine and in nuclear medicine. The most important field is cancer. A regular nanotechnology training program for nuclear medicine physicians may be welcome.

  20. Stress, Burnout and Coping Strategies in Preclinical Medical Students.

    PubMed

    Fares, Jawad; Al Tabosh, Hayat; Saadeddin, Zein; El Mouhayyar, Christopher; Aridi, Hussam

    2016-02-01

    It is acknowledged that physicians do not seek the same expert aid for themselves as they would offer their patients. In their preclinical years, medical students appear to espouse comparable behavior. To many, medicine is described as a never-ending path that places the student under heavy stress and burnout from the beginning, leaving him/her vulnerable and with insufficient coping methods. Hence, the objective of this study is to 1) explore the prevalence of stress and burnout among preclinical medical students, and 2) propose solutions to decrease stress and burnout and improve medical education in the preclinical years. A detailed scholarly research strategy using Google Scholar, Scopus, Embase, MEDLINE and PubMed was implemented to highlight key themes that are relevant to preclinical medical students' stress and burnout. Stress varied among different samples of medical students and ranged between 20.9% and 90%. Conversely, burnout ranged between 27% and 75%. Methods that help in reducing the incidence of stress and burnout by promoting strategies that focus on personal engagement, extracurricular activities, positive reinterpretation and expression of emotion, student-led mentorship programs, evaluation systems, career counseling and life coaching should be adopted.

  1. USHERING IN THE STUDY AND TREATMENT OF PRECLINICAL ALZHEIMER DISEASE

    PubMed Central

    Langbaum, Jessica B.S.; Fleisher, Adam S.; Chen, Kewei; Ayutyanont, Napatkamon; Lopera, Francisco; Quiroz, Yakeel T.; Caselli, Richard J.; Tariot, Pierre N.; Reiman, Eric M.

    2014-01-01

    Researchers have begun to characterize the subtle biological and cognitive processes that precede the clinical onset of Alzheimer disease (AD), and to set the stage for accelerated evaluation of experimental treatments to delay the onset, reduce the risk of or completely prevent clinical decline. Here, we provide an overview of the experimental strategies, and brain imaging and cerebrospinal fluid biomarker measures that are used in early detection and tracking of AD, highlighting at-risk individuals who could be suitable for preclinical monitoring. We discuss how these advances have contributed to reconceptualization of AD as a sequence of biological changes that occur during progression from preclinical AD, to mild cognitive impairment and finally dementia, and we review recently proposed research criteria for preclinical AD. Advances in the study of preclinical AD have driven the recognition that efficacy of at least some AD therapies may depend on initiation of treatment before clinical manifestation of disease, leading to a new era of AD prevention research. PMID:23752908

  2. Ushering in the study and treatment of preclinical Alzheimer disease.

    PubMed

    Langbaum, Jessica B; Fleisher, Adam S; Chen, Kewei; Ayutyanont, Napatkamon; Lopera, Francisco; Quiroz, Yakeel T; Caselli, Richard J; Tariot, Pierre N; Reiman, Eric M

    2013-07-01

    Researchers have begun to characterize the subtle biological and cognitive processes that precede the clinical onset of Alzheimer disease (AD), and to set the stage for accelerated evaluation of experimental treatments to delay the onset, reduce the risk of, or completely prevent clinical decline. In this Review, we provide an overview of the experimental strategies, and brain imaging and cerebrospinal fluid biomarker measures that are used in early detection and tracking of AD, highlighting at-risk individuals who could be suitable for preclinical monitoring. We discuss how advances in the field have contributed to reconceptualization of AD as a sequence of biological changes that occur during progression from preclinical AD, to mild cognitive impairment and finally dementia, and we review recently proposed research criteria for preclinical AD. Advances in the study of preclinical AD have driven the recognition that efficacy of at least some AD therapies may depend on initiation of treatment before clinical manifestation of disease, leading to a new era of AD prevention research.

  3. The neuropsychology of normal aging and preclinical Alzheimer's disease.

    PubMed

    Caselli, Richard J; Locke, Dona E C; Dueck, Amylou C; Knopman, David S; Woodruff, Bryan K; Hoffman-Snyder, Charlene; Rademakers, Rosa; Fleisher, Adam S; Reiman, Eric M

    2014-01-01

    A National Institute on Aging-sponsored work group on preclinical Alzheimer's disease (AD) articulated the need to characterize cognitive differences between normal aging and preclinical AD. Seventy-one apolipoprotein E (APOE) ε4 homozygotes, 194 ε3/ε4 heterozygotes, and 356 ε4 noncarriers age 21 to 87 years who were cognitively healthy underwent neuropsychological testing every 2 years. Longitudinal trajectories of test scores were compared between APOE subgroups. There was a significant effect of age on all cognitive domains in both APOE ε4 carriers and noncarriers. A significant effect of APOE ε4 gene dose was confined to the memory domain and the Dementia Rating Scale. Cross-sectional comparisons did not discriminate the groups. Although cognitive aging patterns are similar in APOE ε4 carriers and noncarriers, preclinical AD is characterized by a significant ε4 gene dose effect that impacts memory and is detectable longitudinally. Preclinical neuropsychological testing strategies should emphasize memory-sensitive measures and longitudinal design. Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  4. Relationships between Preclinical Course Grades and Standardized Exam Performance

    ERIC Educational Resources Information Center

    Hu, Yinin; Martindale, James R.; LeGallo, Robin D.; White, Casey B.; McGahren, Eugene D.; Schroen, Anneke T.

    2016-01-01

    Success in residency matching is largely contingent upon standardized exam scores. Identifying predictors of standardized exam performance could promote primary intervention and lead to design insights for preclinical courses. We hypothesized that clinically relevant courses with an emphasis on higher-order cognitive understanding are most…

  5. Sugary beverage intake and preclinical Alzheimer's disease in the community

    USDA-ARS?s Scientific Manuscript database

    IMPORTANCE: Sugary beverages are a key component of the Western diet, yet the long-term effects of these beverages on the brain are poorly understood. OBJECTIVE: To determine whether habitual sugary beverage consumption is associated with markers of preclinical Alzheimers disease (AD) and/or vascu...

  6. Perspective: Recommendations for benchmarking pre-clinical studies of nanomedicines

    PubMed Central

    Dawidczyk, Charlene M.; Russell, Luisa M.; Searson, Peter C.

    2015-01-01

    Nanoparticle-based delivery systems provide new opportunities to overcome the limitations associated with traditional small molecule drug therapy for cancer, and to achieve both therapeutic and diagnostic functions in the same platform. Pre-clinical trials are generally designed to assess therapeutic potential and not to optimize the design of the delivery platform. Consequently, progress in developing design rules for cancer nanomedicines has been slow, hindering progress in the field. Despite the large number of pre-clinical trials, several factors restrict comparison and benchmarking of different platforms, including variability in experimental design, reporting of results, and the lack of quantitative data. To solve this problem, we review the variables involved in the design of pre-clinical trials and propose a protocol for benchmarking that we recommend be included in in vivo pre-clinical studies of drug delivery platforms for cancer therapy. This strategy will contribute to building the scientific knowledge base that enables development of design rules and accelerates the translation of new technologies. PMID:26249177

  7. Cardiac AAV9-S100A1 gene therapy rescues postischemic heart failure in a preclinical large animal model

    PubMed Central

    Pleger, Sven T.; Shan, Changguang; Ksienzyk, Jan; Bekeredjian, Raffi; Boekstegers, Peter; Hinkel, Rabea; Schinkel, Stefanie; Leuchs, Barbara; Ludwig, Jochen; Qiu, Gang; Weber, Christophe; Kleinschmidt, Jürgen A.; Raake, Philip; Koch, Walter J.; Katus, Hugo A.; Müller, Oliver J.; Most, Patrick

    2014-01-01

    As a prerequisite to clinical application, we determined the long-term therapeutic effectiveness and safety of adeno-associated viral (AAV) S100A1 gene therapy in a preclinical, large animal model of heart failure. S100A1, a positive inotropic regulator of myocardial contractility, becomes depleted in failing cardiomyocytes in humans and various animal models, and myocardial-targeted S100A1 gene transfer rescues cardiac contractile function by restoring sarcoplasmic reticulum calcium Ca2+ handling in acutely and chronically failing hearts in small animal models. We induced heart failure in domestic pigs by balloon-occlusion of the left circumflex coronary artery, resulting in myocardial infarction. After 2 weeks, when the pigs displayed significant left ventricular contractile dysfunction, we administered through retrograde coronary venous delivery, AAV9-S100A1 to the left ventricular non-infarcted myocardium. AAV9-luciferase and saline treatment served as control. At 14 weeks, both control groups showed significantly decreased myocardial S100A1 protein expression along with progressive deterioration of cardiac performance and left ventricular remodeling. AAV9-S100A1 treatment prevented and reversed this phenotype by restoring cardiac S100A1 protein levels. S100A1 treatment normalized cardiomyocyte Ca2+ cycling, sarcoplasmic reticulum calcium handling and energy homeostasis. Transgene expression was restricted to cardiac tissue and extra-cardiac organ function was uncompromised indicating a favorable safety profile. This translational study shows the pre-clinical feasibility, long-term therapeutic effectiveness and a favorable safety profile of cardiac AAV9-S100A1 gene therapy in a preclinical model of heart failure. Our study presents a strong rational for a clinical trial of S100A1 gene therapy for human heart failure that could potentially complement current strategies to treat end-stage heart failure. PMID:21775667

  8. Preclinical Torsades-de-Pointes screens: advantages and limitations of surrogate and direct approaches in evaluating proarrhythmic risk.

    PubMed

    Gintant, Gary A

    2008-08-01

    The successful development of novel drugs requires the ability to detect (and avoid) compounds that may provoke Torsades-de-Pointes (TdeP) arrhythmia while endorsing those compounds with minimal torsadogenic risk. As TdeP is a rare arrhythmia not readily observed during clinical or post-marketing studies, numerous preclinical models are employed to assess delayed or altered ventricular repolarization (surrogate markers linked to enhanced proarrhythmic risk). This review evaluates the advantages and limitations of selected preclinical models (ranging from the simplest cellular hERG current assay to the more complex in vitro perfused ventricular wedge and Langendorff heart preparations and in vivo chronic atrio-ventricular (AV)-node block model). Specific attention is paid to the utility of concentration-response relationships and "risk signatures" derived from these studies, with the intention of moving beyond predicting clinical QT prolongation and towards prediction of TdeP risk. While the more complex proarrhythmia models may be suited to addressing questionable or conflicting proarrhythmic signals obtained with simpler preclinical assays, further benchmarking of proarrhythmia models is required for their use in the robust evaluation of safety margins. In the future, these models may be able to reduce unwarranted attrition of evolving compounds while becoming pivotal in the balanced integrated risk assessment of advancing compounds.

  9. The Preclinical and Clinical Effects of Vilazodone for the Treatment of Major Depressive Disorder

    PubMed Central

    Sahli, Zeyad T.; Banerjee, Pradeep; Tarazi, Frank I.

    2016-01-01

    ABSTRACT Introduction: Major depressive disorder (MDD) is the leading cause of disability worldwide, and according to the STAR*D trial, only 33% of patients with MDD responded to initial drug therapy. Augmentation of the leading class of antidepressant treatment, selective serotonin reuptake inhibitors (SSRIs), with the 5-HT1A receptor agonist buspirone has been shown to be effective in treating patients that do not respond to initial SSRI therapy. This suggests that newer treatments may improve the clinical picture of MDD. The US Food and Drug Administration (FDA) approved the antidepressant drug vilazodone (EMD 68843), a novel SSRI and 5-HT1A receptor partial agonist. Vilazodone has a half-life between 20–24 hours, reaches peak plasma concentrations at 3.7–5.3 hours, and is primarily metabolized by the hepatic CYP450 3A4 enzyme system. Areas covered: The authors review the preclinical and clinical profile of vilazodone. The roles of serotonin, the 5-HT1A receptor, and current pharmacotherapy approaches for MDD are briefly reviewed. Next, the preclinical pharmacological, behavioral, and physiological effects of vilazodone are presented, followed by the pharmacokinetic properties and metabolism of vilazodone in humans. Last, a brief summary of the main efficacy, safety, and tolerability outcomes of clinical trials of vilazodone is provided. Expert opinion: Vilazodone has shown efficacy versus placebo in improving depression symptoms in several double-blind, placebo-controlled trials. The long-term safety and tolerability of vilazodone treatment has also been established. Further studies are needed that directly compare patients treated with an SSRI (both with and without an adjunctive 5-HT1A partial agonist) versus patients treated with vilaozodone. PMID:26971593

  10. Preclinical assessment of a new recombinant ADAMTS-13 drug product (BAX930) for the treatment of thrombotic thrombocytopenic purpura.

    PubMed

    Kopić, A; Benamara, K; Piskernik, C; Plaimauer, B; Horling, F; Höbarth, G; Ruthsatz, T; Dietrich, B; Muchitsch, E-M; Scheiflinger, F; Turecek, M; Höllriegl, W

    2016-07-01

    Essentials ADAMTS-13-deficiency is a cause of thrombotic thrombocytopenic purpura (TTP). Preclinical safety of recombinant human ADAMTS-13 (BAX930) was shown in animal models. Preclinical efficacy of BAX930 was shown in a mouse model of TTP. BAX930 showed advantageous efficacy over fresh frozen plasma, the current standard of care. Click to hear Dr Cataland and Prof. Lämmle present a seminar on Thrombotic Thrombocytopenic Purpura (TTP): new Insights in Pathogenesis and Treatment Modalities. Background Thrombotic thrombocytopenic purpura (TTP) is a rare blood disorder characterized by microthrombosis in small blood vessels of the body, resulting in a low platelet count. Baxalta has developed a new recombinant ADAMTS-13 (rADAMTS-13) product (BAX930) for on-demand and prophylactic treatment of patients with hereditary TTP (hTTP). Objectives To evaluate the pharmacokinetics, efficacy and safety of BAX930 in different species, by use of an extensive preclinical program. Methods The prophylactic and therapeutic efficacies of BAX930 were tested in a previously established TTP mouse model. Pharmacokinetics were evaluated after single intravenous bolus injection in mice and rats, and after repeated dosing in cynomolgus monkeys. Toxicity was assessed in rats and monkeys, safety pharmacology in monkeys, and local tolerance in rabbits. Results BAX930 was shown to be efficacious, as demonstrated by a stabilized platelet count in ADAMTS-13 knockout mice that were thrombocytopenic when treated. Prophylactic efficacy was dose-dependent and comparable with that achieved by treatment with fresh frozen plasma, the mainstay of hTTP treatment. Therapeutic efficacy was treatment interval-dependent. Safety pharmacology evaluation did not show any deleterious effects of BAX930 on cardiovascular and respiratory functions in monkeys. The compound's pharmacokinetics were similar and dose-proportional in mice, rats, and monkeys. BAX930 was well tolerated in rats, monkeys, and rabbits, even

  11. Preclinical acute toxicity, biodistribution, pharmacokinetics, radiation dosimetry and microPET imaging studies of [(18)F]fluorocholine in mice.

    PubMed

    Silveira, Marina B; Ferreira, Soraya M Z M D; Nascimento, Leonardo T C; Costa, Flávia M; Mendes, Bruno M; Ferreira, Andrea V; Malamut, Carlos; Silva, Juliana B; Mamede, Marcelo

    2016-10-01

    [(18)F]Fluorocholine ([(18)F]FCH) has been proven to be effective in prostate cancer. Since [(18)F]FCH is classified as a new radiopharmaceutical in Brazil, preclinical safety and efficacy data are required to support clinical trials and to obtain its approval. The aim of this work was to perform acute toxicity, biodistribution, pharmacokinetics, radiation dosimetry and microPET imaging studies of [(18)F]FCH. The results could support its use in nuclear medicine as an important piece of work for regulatory in Brazil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Preclinical dose number and its application in understanding drug absorption risk and formulation design for preclinical species.

    PubMed

    Wuelfing, W Peter; Daublain, Pierre; Kesisoglou, Filippos; Templeton, Allen; McGregor, Caroline

    2015-04-06

    In the drug discovery setting, the ability to rapidly identify drug absorption risk in preclinical species at high doses from easily measured physical properties is desired. This is due to the large number of molecules being evaluated and their high attrition rate, which make resource-intensive in vitro and in silico evaluation unattractive. High-dose in vivo data from rat, dog, and monkey are analyzed here, using a preclinical dose number (PDo) concept based on the dose number described by Amidon and other authors (Pharm. Res., 1993, 10, 264-270). PDo, as described in this article, is simply calculated as dose (mg/kg) divided by compound solubility in FaSSIF (mg/mL) and approximates the volume of biorelevant media per kilogram of animal that would be needed to fully dissolve the dose. High PDo values were found to be predictive of difficulty in achieving drug exposure (AUC)-dose proportionality in in vivo studies, as could be expected; however, this work analyzes a large data set (>900 data points) and provides quantitative guidance to identify drug absorption risk in preclinical species based on a single solubility measurement commonly carried out in drug discovery. Above the PDo values defined, >50% of all in vivo studies exhibited poor AUC-dose proportionality in rat, dog, and monkey, and these values can be utilized as general guidelines in discovery and early development to rapidly assess risk of solubility-limited absorption for a given compound. A preclinical dose number generated by biorelevant dilutions of formulated compounds (formulated PDo) was also evaluated and defines solubility targets predictive of suitable AUC-dose proportionality in formulation development efforts. Application of these guidelines can serve to efficiently identify compounds in discovery that are likely to present extreme challenges with respect to solubility-limited absorption in preclinical species as well as reduce the testing of poor formulations in vivo, which is a key

  13. [Kagocel in the therapy of influenza and acute respiratory viral infections: Data analysis and systematization from the results of preclinical and clinical trials].

    PubMed

    Sologub, T V; Tsvetkov, V V

    The article provides the summarized data of clinical trials evaluating the efficacy and safety of kagocel used to prevent and treat influenza and acute respiratory viral infections of different etiologies. The results of numerous preclinical and clinical trials suggest that the kagocel substance is highly safe and that it is appropriate to use the drug for the treatment and prevention of influenza and acute respiratory viral infections of another etiology.

  14. Global Phosphoproteomic Analysis of Insulin/Akt/mTORC1/S6K Signaling in Rat Hepatocytes.

    PubMed

    Zhang, Yuanyuan; Zhang, Yajie; Yu, Yonghao

    2017-08-04

    Insulin resistance is a hallmark of type 2 diabetes. Although multiple genetic and physiological factors interact to cause insulin resistance, deregulated signaling by phosphorylation is a common underlying mechanism. In particular, the specific phosphorylation-dependent regulatory mechanisms and signaling outputs of insulin are poorly understood in hepatocytes, which represents one of the most important insulin-responsive cell types. Using primary rat hepatocytes as a model system, we performed reductive dimethylation (ReDi)-based quantitative mass spectrometric analysis and characterized the phosphoproteome that is regulated by insulin as well as its key downstream kinases including Akt, mTORC1, and S6K. We identified a total of 12 294 unique, confidently localized phosphorylation sites and 3805 phosphorylated proteins in this single cell type. Detailed bioinformatic analysis on each individual data set identified both known and previously unrecognized targets of this key insulin downstream effector pathway. Furthermore, integrated analysis of the hepatic Akt/mTORC1/S6K signaling axis allowed the delineation of the substrate specificity of several close-related kinases within the insulin signaling pathway. We expect that the data sets will serve as an invaluable resource, providing the foundation for future hypothesis-driven research that helps delineate the molecular mechanisms that underlie the pathogenesis of type 2 diabetes and related metabolic syndrome.

  15. Issues in transferring preclinical skill learning to the clinical context.

    PubMed

    Chambers, D W

    1987-05-01

    The relationship between student performance in preclinical technique laboratory courses and in clinic is not straightforward. While American dental education in the preclinical courses is effective in teaching mastery of fundamentals to most students and identifying those who should not proceed to patient care, the prediction from technique laboratory performance of who will do well in clinic is weak. Factors accounting for this poor correlation include differences in the mix of skills required in the two contexts, failure to teach for transfer of skills to new settings, and laboratory education practices that create clinically dysfunctional habits. As a means of understanding the transfer issue, a distinction is made among task as given by the instructor, task as interpreted by the student, and task as negotiated in the interpersonal context of dental education.

  16. Preclinical diagnosis of Alzheimer’s disease: Prevention or prediction?

    PubMed Central

    Nitrini, Ricardo

    2010-01-01

    The diagnosis of Alzheimer’s disease (AD) for cases with dementia may be too late to allow effective treatment. Criteria for diagnosis of preclinical AD suggested by the Alzheimer’s Association include the use of molecular and structural biomarkers. Preclinical diagnosis will enable testing of new drugs and forms of treatment toward achieving successful preventive treatment. But what are the advantages for the individual? To know that someone who is cognitively normal is probably going to develop AD’s dementia when there is no effective preventive treatment is definitely not good news. A research method whereby volunteers are assigned to receive treatment or placebo without knowing whether they are in the control or at-risk arm of a trial would overcome this potential problem. If these new criteria are used wisely they may represent a relevant milestone in the search for a definitive treatment for AD. PMID:29213696

  17. Preclinical Alzheimer's disease: Definition, natural history, and diagnostic criteria.

    PubMed

    Dubois, Bruno; Hampel, Harald; Feldman, Howard H; Scheltens, Philip; Aisen, Paul; Andrieu, Sandrine; Bakardjian, Hovagim; Benali, Habib; Bertram, Lars; Blennow, Kaj; Broich, Karl; Cavedo, Enrica; Crutch, Sebastian; Dartigues, Jean-François; Duyckaerts, Charles; Epelbaum, Stéphane; Frisoni, Giovanni B; Gauthier, Serge; Genthon, Remy; Gouw, Alida A; Habert, Marie-Odile; Holtzman, David M; Kivipelto, Miia; Lista, Simone; Molinuevo, José-Luis; O'Bryant, Sid E; Rabinovici, Gil D; Rowe, Christopher; Salloway, Stephen; Schneider, Lon S; Sperling, Reisa; Teichmann, Marc; Carrillo, Maria C; Cummings, Jeffrey; Jack, Cliff R

    2016-03-01

    During the past decade, a conceptual shift occurred in the field of Alzheimer's disease (AD) considering the disease as a continuum. Thanks to evolving biomarker research and substantial discoveries, it is now possible to identify the disease even at the preclinical stage before the occurrence of the first clinical symptoms. This preclinical stage of AD has become a major research focus as the field postulates that early intervention may offer the best chance of therapeutic success. To date, very little evidence is established on this "silent" stage of the disease. A clarification is needed about the definitions and lexicon, the limits, the natural history, the markers of progression, and the ethical consequence of detecting the disease at this asymptomatic stage. This article is aimed at addressing all the different issues by providing for each of them an updated review of the literature and evidence, with practical recommendations. Copyright © 2016 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  18. Modeling mania in preclinical settings: a comprehensive review

    PubMed Central

    Sharma, Ajaykumar N.; Fries, Gabriel R.; Galvez, Juan F.; Valvassori, Samira S.; Soares, Jair C.; Carvalho, André F.; Quevedo, Joao

    2015-01-01

    The current pathophysiological understanding of mechanisms leading to onset and progression of bipolar manic episodes remains limited. At the same time, available animal models for mania have limited face, construct, and predictive validities. Additionally, these models fail to encompass recent pathophysiological frameworks of bipolar disorder (BD), e.g. neuroprogression. Therefore, there is a need to search for novel preclinical models for mania that could comprehensively address these limitations. Herein we review the history, validity, and caveats of currently available animal models for mania. We also review new genetic models for mania, namely knockout mice for genes involved in neurotransmission, synapse formation, and intracellular signaling pathways. Furthermore, we review recent trends in preclinical models for mania that may aid in the comprehension of mechanisms underlying the neuroprogressive and recurring nature of BD. In conclusion, the validity of animal models for mania remains limited. Nevertheless, novel (e.g. genetic) animal models as well as adaptation of existing paradigms hold promise. PMID:26545487

  19. Spatial reversal learning in preclinical scrapie-inoculated mice.

    PubMed

    Lysons, A M; Woollard, S J

    1996-04-10

    Acquisition and reversal of a two-choice spatial discrimination were tested in scrapie-inoculated mice. Both acquisition and reversal were normal in mice tested 138 and 103 days prior to the onset of clinical symptoms. At 65 days before onset of clinical symptoms, scrapie-inoculated mice required more trails to criterion in reversal learning, but this effect was not significant in a second experiment (68 days preclinical) and was transient: no effect was seen 33 days before symptoms. However, the course of reversal learning was abnormal in all three late preclinical groups (68, 65 and 33 days before symptoms). Reversal learning in these three groups was characterized by a rapid extinction of the original discrimination, followed by a period, absent in controls, during which performance showed no further improvement. This effect corresponds in time of onset to the appearance of characteristic neuropathological features.

  20. Mesenchymal stem cells for acute lung injury: Preclinical evidence

    PubMed Central

    Matthay, Michael A.; Goolaerts, Arnaud; Howard, James P.; Lee, Jae Woo

    2013-01-01

    Several experimental studies have suggested that mesenchymal stem cells may have value for the treatment of clinical disorders, including myocardial infarction, diabetes, acute renal failure, sepsis, and acute lung injury. In preclinical studies, mesenchymal stem cells have been effective in reducing lung injury from endotoxin, live bacteria, bleomycin, and hyperoxia. In some studies, the cultured medium from mesenchymal stem cells has been as effective as the mesenchymal stem cells themselves. Several paracrine mediators that can mediate the effect of mesenchymal stem cells have been identified, including interleukin-10, interleukin-1ra, keratinocyte growth factor, and prostaglandin E2. Further preclinical studies are needed, as is planning for clinical trials for acute lung injury. PMID:21164399

  1. Cannabinoids and Dementia: A Review of Clinical and Preclinical Data

    PubMed Central

    Walther, Sebastian; Halpern, Michael

    2010-01-01

    The endocannabinoid system has been shown to be associated with neurodegenerative diseases and dementia. We review the preclinical and clinical data on cannabinoids and four neurodegenerative diseases: Alzheimer’s disease (AD), Huntington’s disease (HD), Parkinson’s disease (PD) and vascular dementia (VD). Numerous studies have demonstrated an involvement of the cannabinoid system in neurotransmission, neuropathology and neurobiology of dementias. In addition, several candidate compounds have demonstrated efficacy in vitro. However, some of the substances produced inconclusive results in vivo. Therefore, only few trials have aimed to replicate the effects seen in animal studies in patients. Indeed, the literature on cannabinoid administration in patients is scarce. While preclinical findings suggest causal treatment strategies involving cannabinoids, clinical trials have only assessed the suitability of cannabinoid receptor agonists, antagonists and cannabidiol for the symptomatic treatment of dementia. Further research is needed, including in vivo models of dementia and human studies. PMID:27713372

  2. Inhibition of Early Stages of HIV-1 Assembly by INI1/hSNF5 Transdominant Negative Mutant S6

    PubMed Central

    Cano, Jennifer; Kalpana, Ganjam V.

    2011-01-01

    INI1/hSNF5 is an HIV-1 integrase (IN) binding protein specifically incorporated into virions. A truncated mutant of INI1 (S6, amino acids 183 to 294) harboring the minimal IN binding Rpt1 domain potently inhibits HIV-1 particle production in a transdominant manner. The inhibition requires interaction of S6 with IN within Gag-Pol. While INI1 is a nuclear protein and harbors a masked nuclear export signal (NES), the transdominant negative mutant S6 is cytoplasmic, due to the unmasking of NES. Here, we examined the effects of subcellular localization of S6 on HIV-1 inhibition and further investigated the stages of assembly that are affected. We found that targeting a nuclear localization signal-containing S6 variant [NLS-S6(Rpt1)] to the nucleoplasm (but not to the nucleolus) resulted in complete reversal of inhibition of particle production. Electron microscopy indicated that although no electron-dense particles at any stage of assembly were seen in cells expressing S6, virions were produced in cells expressing the rescue mutant NLS-S6(Rpt1) to wild-type levels. Immunofluorescence analysis revealed that p24 exhibited a diffuse pattern of localization within the cytoplasm in cells expressing S6 in contrast to accumulation along the membrane in controls. Pulse-chase analysis indicated that in S6-expressing cells, although Gag(Pr55gag) protein translation was unaffected, processing and release of p24 were defective. Together, these results indicate that expression of S6 in the cytoplasm interferes with trafficking of Gag-Pol/Gag to the membrane and causes a defective processing leading to inhibition of assembly at an early stage prior to particle formation and budding. PMID:21159874

  3. Genetically Engineered Humanized Mouse Models for Preclinical Antibody Studies

    PubMed Central

    Proetzel, Gabriele; Wiles, Michael V.; Roopenian, Derry C.

    2015-01-01

    The use of genetic engineering has vastly improved our capabilities to create animal models relevant in preclinical research. With the recent advances in gene-editing technologies, it is now possible to very rapidly create highly tunable mouse models as needs arise. Here, we provide an overview of genetic engineering methods, as well as the development of humanized neonatal Fc receptor (FcRn) models and their use for monoclonal antibody in vivo studies. PMID:24150980

  4. Is adiponectin a marker of preclinical atherosclerosis in kidney transplantation?

    PubMed

    Cañas, Laura; Bayés, Beatriz; Granada, Maria L; Ibernon, Meritxell; Porrini, Esteban; Benítez, Rosa; Díaz, Juan M; Lauzurica, Ricardo; Moreso, Francesc; Torres, Armando; Lampreabe, Ildefonso; Serra, Assumpta; Romero, Ramon

    2012-01-01

    The aim of this study was to analyze the relationship between pre-transplant adiponectin (pre-ADP), abnormalities in glucose homeostasis (AGH) at three months post-transplantation, and preclinical atherosclerosis in non-diabetic patients prior to kidney transplantation (KT). We carried out a multicenter study in 157 non-diabetic KT patients (66.5% men; age: 50±13 yr). Pre-ADP levels were analyzed using radioimmunoassay. Carotid ultrasound was performed to determine carotid intima-media thickness (c-IMT). Oral glucose tolerance test was carried out to classify patients according ADA criteria. Of the patients, 52.8% had AGH. Median pre-ADP was 19.5 (14-27) μg/mL. An inverse correlation was found between ADP and HOMA index (r=-0.432; p<0.001). Median c-IMT was 0.6 (0.48-0.71) mm. Significant inverse correlation existed between ADP and c-IMT on both sides (p<0.05). Patients with c-IMT >0.6 mm had more AGH (p=0.012) and lower ADP levels (p=0.02). We performed a logistic regression analysis using preclinical atherosclerosis (c-IMT ≥0.6 mm) as dependent variable and sex, age, BMI, ADP, AGH, and HOMA index as independent variables of altered c-IMT. Age, pre-ADP, and AGH were independent risk factors for elevated c-IMT. Patients with AGH have a greater presence of preclinical atherosclerosis. ADP has an inverse relationship with AGH and is an independent marker of preclinical atherosclerosis. © 2011 John Wiley & Sons A/S.

  5. The impact of preclinical irreproducibility on drug development.

    PubMed

    Freedman, L P; Gibson, M C

    2015-01-01

    The development of novel therapeutics depends and builds upon the validity and reproducibility of previously published data and findings. Yet irreproducibility is pervasive in preclinical life science research and can be traced to cumulative errors or flaws in several areas, including reference materials, study design, laboratory protocols, and data collection and analysis. The expanded development and use of consensus-based standards and well-documented best practices is needed to both enhance reproducibility and drive therapeutic innovations. © 2014 ASCPT.

  6. [Impact of microdose clinical trials in the preclinical stage].

    PubMed

    Kim, Soonih

    2014-01-01

    A microdose clinical trial may be useful as a safe early-phase exploratory study using doses as low as 100 μg or less for determination of the disposition of a candidate compound in humans in a short period of time. This may increase confidence in candidate compounds, especially those for which it is difficult to predict disposition based on the results of in vitro or preclinical studies. In this study, we examined microdose trials performed in the preclinical stage for two first-in-class compounds with a new mechanism of action. These compounds showed species difference in first pass metabolism in the digestive tract and liver, causing uncertainty in prediction of disposition in humans. For this reason, first-in-human microdose clinical trials were performed. The results showed that the two compounds had effective blood concentrations after oral administration at a dose of 100 mg qd. Administration of an extremely small dose of one (14)C-labeled compound permitted identification of major metabolites. No toxic metabolites were detected. The preclinical toxic dose was determined based on prediction of blood exposure at the estimated maximum clinical dose. For the other candidate compound, the findings of the microdose trial indicated a high bioavailability after oral administration and low hepatic clearance after intravenous administration. These results suggested only a small risk of a change in disposition in patients with hepatic disorder. The data obtained for the two compounds suggest that microdose clinical trials can be useful for improving the process of candidate selection in the preclinical stage.

  7. C-IOP/NiO/Ni7S6 composite with the inverse opal lattice as an electrode for supercapacitors

    NASA Astrophysics Data System (ADS)

    Sukhinina, Nadezhda S.; Masalov, Vladimir M.; Zhokhov, Andrey A.; Zverkova, Irina I.; Emelchenko, Gennadi A.

    2015-06-01

    In this work, we demonstrate the results of studies on the synthesis, the structure and properties of carbon inverted opal (C-IOP) nanostructures, the surface of which is modified by oxide and sulfide of nickel. It is shown that the modification of the matrix C-IOP by nickel compounds led to a decreasing the specific surface area more than three times and was 250 m2/g. The specific capacitance of the capacitor with the C-IOP/NiO/Ni7S6 composite as electrode has increased more than 4 times, from 130 F/g to 600 F/g, as compared with the sample C-IOP without the modification by nickel compounds. The significant contribution of the faradaic reactions in specific capacitance of the capacitor electrodes of the composites is marked.

  8. Antisite Defects in Layered Multiferroic CuCr 0.9In 0.1P 2S 6

    DOE PAGES

    He, Qian; Belianinov, Alex; Dziaugys, Andrius; ...

    2015-10-06

    The CuCr 1-xIn xP 2S 6 system represents a large family of metal chalcogenophosphates that are unique and promising candidates for 2D materials with functionalities such as ferroelectricity. We carried out detailed microstructural and chemical characterization of these compounds using aberration-corrected STEM, in order to understand the origin of these different ordering phenomena. Quantitative STEM-HAADF imaging and analysis identified the stacking order of an 8-layer thin flake, which leads to the identification of anti-site In 3+(Cu +) doping. We believe that these findings will pave the way towards understanding the ferroic coupling phenomena in van der Waals lamellar compounds, asmore » well as the potential applications in 2-D electronics.« less

  9. Antisite defects in layered multiferroic CuCr(0.9)In(0.1)P2S6.

    PubMed

    He, Qian; Belianinov, Alex; Dziaugys, Andrius; Maksymovych, Petro; Vysochanskii, Yulian; Kalinin, Sergei V; Borisevich, Albina Y

    2015-11-28

    The CuCr1-xInxP2S6 system represents a large family of metal chalcogenophosphates that are unique and promising candidates for 2D materials with functionalities such as ferroelectricity. In this work, we carried out detailed microstructural and chemical characterization of these compounds using aberration-corrected STEM, in order to understand the origin of these different ordering phenomena. Quantitative STEM-HAADF imaging and analysis identified the stacking order of an 8-layer thin flake, which leads to the identification of anti-site In(3+)(Cu(+)) doping. We believe that these findings will pave the way towards understanding the ferroic coupling phenomena in van der Waals lamellar compounds, as well as their potential applications in 2-D electronics.

  10. Antisite defects in layered multiferroic CuCr0.9In0.1P2S6

    NASA Astrophysics Data System (ADS)

    He, Qian; Belianinov, Alex; Dziaugys, Andrius; Maksymovych, Petro; Vysochanskii, Yulian; Kalinin, Sergei V.; Borisevich, Albina Y.

    2015-11-01

    The CuCr1-xInxP2S6 system represents a large family of metal chalcogenophosphates that are unique and promising candidates for 2D materials with functionalities such as ferroelectricity. In this work, we carried out detailed microstructural and chemical characterization of these compounds using aberration-corrected STEM, in order to understand the origin of these different ordering phenomena. Quantitative STEM-HAADF imaging and analysis identified the stacking order of an 8-layer thin flake, which leads to the identification of anti-site In3+(Cu+) doping. We believe that these findings will pave the way towards understanding the ferroic coupling phenomena in van der Waals lamellar compounds, as well as their potential applications in 2-D electronics.The CuCr1-xInxP2S6 system represents a large family of metal chalcogenophosphates that are unique and promising candidates for 2D materials with functionalities such as ferroelectricity. In this work, we carried out detailed microstructural and chemical characterization of these compounds using aberration-corrected STEM, in order to understand the origin of these different ordering phenomena. Quantitative STEM-HAADF imaging and analysis identified the stacking order of an 8-layer thin flake, which leads to the identification of anti-site In3+(Cu+) doping. We believe that these findings will pave the way towards understanding the ferroic coupling phenomena in van der Waals lamellar compounds, as well as their potential applications in 2-D electronics. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04779j

  11. Preclinical Magnetic Resonance Imaging and Systems Biology in Cancer Research

    PubMed Central

    Albanese, Chris; Rodriguez, Olga C.; VanMeter, John; Fricke, Stanley T.; Rood, Brian R.; Lee, YiChien; Wang, Sean S.; Madhavan, Subha; Gusev, Yuriy; Petricoin, Emanuel F.; Wang, Yue

    2014-01-01

    Biologically accurate mouse models of human cancer have become important tools for the study of human disease. The anatomical location of various target organs, such as brain, pancreas, and prostate, makes determination of disease status difficult. Imaging modalities, such as magnetic resonance imaging, can greatly enhance diagnosis, and longitudinal imaging of tumor progression is an important source of experimental data. Even in models where the tumors arise in areas that permit visual determination of tumorigenesis, longitudinal anatomical and functional imaging can enhance the scope of studies by facilitating the assessment of biological alterations, (such as changes in angiogenesis, metabolism, cellular invasion) as well as tissue perfusion and diffusion. One of the challenges in preclinical imaging is the development of infrastructural platforms required for integrating in vivo imaging and therapeutic response data with ex vivo pathological and molecular data using a more systems-based multiscale modeling approach. Further challenges exist in integrating these data for computational modeling to better understand the pathobiology of cancer and to better affect its cure. We review the current applications of preclinical imaging and discuss the implications of applying functional imaging to visualize cancer progression and treatment. Finally, we provide new data from an ongoing preclinical drug study demonstrating how multiscale modeling can lead to a more comprehensive understanding of cancer biology and therapy. PMID:23219428

  12. Identification of new treatments for epilepsy: issues in preclinical methodology

    PubMed Central

    Galanopoulou, Aristea S.; Buckmaster, Paul S.; Staley, Kevin J.; Moshé, Solomon L.; Perucca, Emilio; Engel, Jerome; Löscher, Wolfgang; Noebels, Jeffrey L.; Pitkänen, Asla; Stables, James; White, Steve H.; O’Brien, Terence J.; Simonato, Michele

    2013-01-01

    Summary Preclinical research has facilitated the discovery of valuable drugs for the symptomatic treatment of epilepsy. Yet, despite these therapies, seizures are not adequately controlled in a third of all affected individuals, and comorbidities still impose a major burden on quality of life. The introduction of multiple new therapies into clinical use over the past two decades has done little to change this. There is an urgent demand to address the unmet clinical needs for: (a) new symptomatic anti-seizure treatments for drug-resistant seizures with improved efficacy/tolerability profiles, (b) disease modifying treatments that prevent or ameliorate the epileptogenic state, and (c) treatments for the common comorbidities that contribute to disability in people with epilepsy. New therapies also need to address the special needs of certain subpopulations, i.e. age- or gender-specific treatments. Preclinical development in these treatment areas is complex due to heterogeneity in presentation and etiology, and may need to be formulated with a specific seizure, epilepsy syndrome or comorbidity in mind. The aim of this report is to provide a framework that will help define future guidelines that improve and standardize the design, reporting, and validation of data across preclinical anti-epilepsy therapy development studies targeting drug-resistant seizures, epileptogenesis and comorbidities. PMID:22292566

  13. Alzheimer's Therapeutics: Translation of Preclinical Science to Clinical Drug Development

    PubMed Central

    Savonenko, Alena V; Melnikova, Tatiana; Hiatt, Andrew; Li, Tong; Worley, Paul F; Troncoso, Juan C; Wong, Phil C; Price, Don L

    2012-01-01

    Over the past three decades, significant progress has been made in understanding the neurobiology of Alzheimer's disease. In recent years, the first attempts to implement novel mechanism-based treatments brought rather disappointing results, with low, if any, drug efficacy and significant side effects. A discrepancy between our expectations based on preclinical models and the results of clinical trials calls for a revision of our theoretical views and questions every stage of translation—from how we model the disease to how we run clinical trials. In the following sections, we will use some specific examples of the therapeutics from acetylcholinesterase inhibitors to recent anti-Aβ immunization and γ-secretase inhibition to discuss whether preclinical studies could predict the limitations in efficacy and side effects that we were so disappointed to observe in recent clinical trials. We discuss ways to improve both the predictive validity of mouse models and the translation of knowledge between preclinical and clinical stages of drug development. PMID:21937983

  14. Identification of new epilepsy treatments: issues in preclinical methodology.

    PubMed

    Galanopoulou, Aristea S; Buckmaster, Paul S; Staley, Kevin J; Moshé, Solomon L; Perucca, Emilio; Engel, Jerome; Löscher, Wolfgang; Noebels, Jeffrey L; Pitkänen, Asla; Stables, James; White, H Steve; O'Brien, Terence J; Simonato, Michele

    2012-03-01

    Preclinical research has facilitated the discovery of valuable drugs for the symptomatic treatment of epilepsy. Yet, despite these therapies, seizures are not adequately controlled in a third of all affected individuals, and comorbidities still impose a major burden on quality of life. The introduction of multiple new therapies into clinical use over the past two decades has done little to change this. There is an urgent demand to address the unmet clinical needs for: (1) new symptomatic antiseizure treatments for drug-resistant seizures with improved efficacy/tolerability profiles, (2) disease-modifying treatments that prevent or ameliorate the process of epileptogenesis, and (3) treatments for the common comorbidities that contribute to disability in people with epilepsy. New therapies also need to address the special needs of certain subpopulations, that is, age- or gender-specific treatments. Preclinical development in these treatment areas is complex due to heterogeneity in presentation and etiology, and may need to be formulated with a specific seizure, epilepsy syndrome, or comorbidity in mind. The aim of this report is to provide a framework that will help define future guidelines that improve and standardize the design, reporting, and validation of data across preclinical antiepilepsy therapy development studies targeting drug-resistant seizures, epileptogenesis, and comorbidities. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

  15. A cost-effective simulation curriculum for preclinical endodontics.

    PubMed

    Pileggi, Roberta; Glickman, Gerald N

    2004-02-01

    A challenge in contemporary dental education is to achieve a smooth transition from preclinical teaching environments to patient-care clinics in a cost-effective manner. The preclinical endodontic courses at The University of Texas, Dental Branch at Houston provide a unique learning environment that enables the student to perform endodontic treatment on extracted teeth in a typodont, and be involved in diagnosis and treatment-planning discussions. The specially designed stone typodont used has built-in radiographic capability, and is mounted at each chair in the clinic. During each preclinical session, students are assigned clinical cubicles and proper aseptic protocol is followed. Students are required to wear gloves, masks and eyewear, and place a rubber dam during treatment. Written self-assessment evaluations based upon prescribed criteria are utilised; feedback is given by faculty composed of both full-time endodontists and graduate students who periodically rotate and are calibrated on a regular basis. In the lecture phase, clinical case scenarios are presented to reinforce concepts of diagnosis and emergency care and to help integrate endodontics with other disciplines; a Socratic-like teaching style is established by the faculty facilitator to create an environment for developing critical-thinking and problem-solving skills. The overall feedback from graduating students has been very positive. Advantages of this format are an easier transition to patient management, a more keen interest in specialsation and a perceived increase in levels of confidence.

  16. Preclinical experimental stress studies: protocols, assessment and comparison.

    PubMed

    Bali, Anjana; Jaggi, Amteshwar Singh

    2015-01-05

    Stress is a state of threatened homeostasis during which a variety of adaptive processes are activated to produce physiological and behavioral changes. Preclinical models are pivotal for understanding these physiological or pathophysiological changes in the body in response to stress. Furthermore, these models are also important for the development of novel pharmacological agents for stress management. The well described preclinical stress models include immobilization, restraint, electric foot shock and social isolation stress. Stress assessment in animals is done at the behavioral level using open field, social interaction, hole board test; at the biochemical level by measuring plasma corticosterone and ACTH; at the physiological level by measuring food intake, body weight, adrenal gland weight and gastric ulceration. Furthermore the comparison between different stressors including electric foot shock, immobilization and cold stressor is described in terms of intensity, hormonal release, protein changes in brain, adaptation and sleep pattern. This present review describes these preclinical stress protocols, and stress assessment at different levels. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Is medical students' moral orientation changeable after preclinical medical education?

    PubMed

    Lin, Chaou-Shune; Tsou, Kuo-Inn; Cho, Shu-Ling; Hsieh, Ming-Shium; Wu, Hsi-Chin; Lin, Chyi-Her

    2012-03-01

    Moral orientation can affect ethical decision-making. Very few studies have focused on whether medical education can change the moral orientation of the students. The purpose of the present study was to document the types of moral orientation exhibited by medical students, and to study if their moral orientation was changed after preclinical education. From 2007 to 2009, the Mojac scale was used to measure the moral orientation of Taiwan medical students. The students included 271 first-year and 109 third-year students. They were rated as a communitarian, dual, or libertarian group and followed for 2 years to monitor the changes in their Mojac scores. In both first and third-year students, the dual group after 2 years of preclinical medical education did not show any significant change. In the libertarian group, first and third-year students showed a statistically significant increase from a score of 99.4 and 101.3 to 103.0 and 105.7, respectively. In the communitarian group, first and third-year students showed a significant decline from 122.8 and 126.1 to 116.0 and 121.5, respectively. During the preclinical medical education years, students with communitarian orientation and libertarian orientation had changed in their moral orientation to become closer to dual orientation. These findings provide valuable hints to medical educators regarding bioethics education and the selection criteria of medical students for admission.

  18. Should preclinical typodonts be disinfected prior to grading?

    PubMed

    Aycock, Jeffrey E; Hill, Edward E

    2009-01-01

    This is a report of a unique finding in a preclinical laboratory that may be a potential dental school health hazard. Visual inspection (conducted in April 2008 by a preclinical crown and bridge course coordinator) of typodonts used by second-year students at the University of Mississippi School of Dentistry found that fourteen out of thirty-nine had black spots on the undersurface of the cheek shroud and/or plastic gingiva. The spots were cultured by the Medical Center's Department of Microbiology and described only as being mold/fungus typical of that which frequently grows in warm, moist, southern environments. Although indoor molds are common, about 5 percent of the general population will develop some type of mild allergic airway problem from molds over their lifetime. Mold on typodonts is unsightly, indicates failure of students to recognize the value of cleanliness in the dental environment, and may be a potential health hazard for some individuals. Cleaning and drying procedures for typodonts were implemented. The transfer of items between students and instructors during preclinical courses provides many opportunities for the spread of potentially harmful microorganisms/viruses. As a minimal level of personal protection, it is suggested that instructors wear disposable gloves and face masks and exercise hand washing between handling student instruments and typodonts. This problem has not been previously mentioned in the literature and merits further investigation/discussion.

  19. Patient-derived xenografts as preclinical neuroblastoma models.

    PubMed

    Braekeveldt, Noémie; Bexell, Daniel

    2018-05-01

    The prognosis for children with high-risk neuroblastoma is often poor and survivors can suffer from severe side effects. Predictive preclinical models and novel therapeutic strategies for high-risk disease are therefore a clinical imperative. However, conventional cancer cell line-derived xenografts can deviate substantially from patient tumors in terms of their molecular and phenotypic features. Patient-derived xenografts (PDXs) recapitulate many biologically and clinically relevant features of human cancers. Importantly, PDXs can closely parallel clinical features and outcome and serve as excellent models for biomarker and preclinical drug development. Here, we review progress in and applications of neuroblastoma PDX models. Neuroblastoma orthotopic PDXs share the molecular characteristics, neuroblastoma markers, invasive properties and tumor stroma of aggressive patient tumors and retain spontaneous metastatic capacity to distant organs including bone marrow. The recent identification of genomic changes in relapsed neuroblastomas opens up opportunities to target treatment-resistant tumors in well-characterized neuroblastoma PDXs. We highlight and discuss the features and various sources of neuroblastoma PDXs, methodological considerations when establishing neuroblastoma PDXs, in vitro 3D models, current limitations of PDX models and their application to preclinical drug testing.

  20. Evaluation of Cholinergic Deficiency in Preclinical Alzheimer's Disease Using Pupillometry

    PubMed Central

    Robinson, Liam; Rowe, Christopher C.; Ames, David; Masters, Colin L.; Taddei, Kevin; Rainey-Smith, Stephanie R.; Martins, Ralph N.; Kanagasingam, Yogesan

    2017-01-01

    Cortical cholinergic deficiency is prominent in Alzheimer's disease (AD), and published findings of diminished pupil flash response in AD suggest that this deficiency may extend to the visual cortical areas and anterior eye. Pupillometry is a low-cost, noninvasive technique that may be useful for monitoring cholinergic deficits which generally lead to memory and cognitive disorders. The aim of the study was to evaluate pupillometry for early detection of AD by comparing the pupil flash response (PFR) in AD (N = 14) and cognitively normal healthy control (HC, N = 115) participants, with the HC group stratified according to high (N = 38) and low (N = 77) neocortical amyloid burden (NAB). Constriction phase PFR parameters were significantly reduced in AD compared to HC (maximum acceleration p < 0.05, maximum velocity p < 0.0005, average velocity p < 0.005, and constriction amplitude p < 0.00005). The high-NAB HC subgroup had reduced PFR response cross-sectionally, and also a greater decline longitudinally, compared to the low-NAB subgroup, suggesting changes to pupil response in preclinical AD. The results suggest that PFR changes may occur in the preclinical phase of AD. Hence, pupillometry has a potential as an adjunct for noninvasive, cost-effective screening for preclinical AD. PMID:28894607

  1. Imaging technologies for preclinical models of bone and joint disorders

    PubMed Central

    2011-01-01

    Preclinical models for musculoskeletal disorders are critical for understanding the pathogenesis of bone and joint disorders in humans and the development of effective therapies. The assessment of these models primarily relies on morphological analysis which remains time consuming and costly, requiring large numbers of animals to be tested through different stages of the disease. The implementation of preclinical imaging represents a keystone in the refinement of animal models allowing longitudinal studies and enabling a powerful, non-invasive and clinically translatable way for monitoring disease progression in real time. Our aim is to highlight examples that demonstrate the advantages and limitations of different imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography (PET), single-photon emission computed tomography (SPECT) and optical imaging. All of which are in current use in preclinical skeletal research. MRI can provide high resolution of soft tissue structures, but imaging requires comparatively long acquisition times; hence, animals require long-term anaesthesia. CT is extensively used in bone and joint disorders providing excellent spatial resolution and good contrast for bone imaging. Despite its excellent structural assessment of mineralized structures, CT does not provide in vivo functional information of ongoing biological processes. Nuclear medicine is a very promising tool for investigating functional and molecular processes in vivo with new tracers becoming available as biomarkers. The combined use of imaging modalities also holds significant potential for the assessment of disease pathogenesis in animal models of musculoskeletal disorders, minimising the use of conventional invasive methods and animal redundancy. PMID:22214535

  2. TOR and S6K1 promote translation reinitiation of uORF-containing mRNAs via phosphorylation of eIF3h

    PubMed Central

    Schepetilnikov, Mikhail; Dimitrova, Maria; Mancera-Martínez, Eder; Geldreich, Angèle; Keller, Mario; Ryabova, Lyubov A

    2013-01-01

    Mammalian target-of-rapamycin (mTOR) triggers S6 kinase (S6K) activation to phosphorylate targets linked to translation in response to energy, nutrients, and hormones. Pathways of TOR activation in plants remain unknown. Here, we uncover the role of the phytohormone auxin in TOR signalling activation and reinitiation after upstream open reading frame (uORF) translation, which in plants is dependent on translation initiation factor eIF3h. We show that auxin triggers TOR activation followed by S6K1 phosphorylation at T449 and efficient loading of uORF-mRNAs onto polysomes in a manner sensitive to the TOR inhibitor Torin-1. Torin-1 mediates recruitment of inactive S6K1 to polysomes, while auxin triggers S6K1 dissociation and recruitment of activated TOR instead. A putative target of TOR/S6K1—eIF3h—is phosphorylated and detected in polysomes in response to auxin. In TOR-deficient plants, polysomes were prebound by inactive S6K1, and loading of uORF-mRNAs and eIF3h was impaired. Transient expression of eIF3h-S178D in plant protoplasts specifically upregulates uORF-mRNA translation. We propose that TOR functions in polysomes to maintain the active S6K1 (and thus eIF3h) phosphorylation status that is critical for translation reinitiation. PMID:23524850

  3. Regulation of mTOR and S6K1 Activation by the nPKC isoforms, PKCε and PKCδ, in Adult Cardiac Muscle Cells

    PubMed Central

    Moschella, Phillip C.; Rao, Vijay U.; McDermott, Paul J.; Kuppuswamy, Dhandapani

    2007-01-01

    SUMMARY Activation of both mTOR and its downstream target, S6K1 (p70 S6 kinase) have been implicated to affect cardiac hypertrophy. Our earlier work, in a feline model of 1–48 h pressure overload, demonstrated that mTOR/S6K1 activation occurred primarily through a PKC/c-Raf pathway. To further delineate the role of specific PKC isoforms on mTOR/S6K1 activation, we utilized primary cultures of adult feline cardiomyocytes in vitro and stimulated with endothelin-1 (ET-1), phenylephrine (PE), TPA, or insulin. All agonist treatments resulted in S2248 phosphorylation of mTOR and T389 and S421/T424 phosphorylation of S6K1, however only ET-1 and TPA-stimulated mTOR/S6K1 activation was abolished with infection of a dominant negative adenoviral c-Raf (DN-Raf) construct. Expression of DN-PKCε blocked ET-1-stimulated mTOR S2448 and S6K1 S421/T424 and T389 phosphorylation but had no effect on insulin-stimulated S6K1 phosphorylation. Expression of DN-PKCδ or pretreatment of cardiomyocytes with rottlerin, a PKCδ specific inhibitor, blocked both ET-1 and insulin stimulated mTOR S2448 and S6K1 T389 phosphorylation. However, treatment with Gö6976, a specific classical PKC (cPKC) inhibitor did not affect mTOR/S6K1 activation. These data indicate that: (i) PKCε is required for ET-1-stimulated T421/S424 phosphorylation of S6K1, (ii) both PKCε and PKCδ are required for ET-1-stimulated mTOR S2448 and S6K1 T389 phosphorylation, (iii) PKCδ is also required for insulin-stimulated mTOR S2448 and S6K1 T389 phosphorylation. Together, these data delineate both distinct and combinatorial roles of specific PKC isoforms on mTOR and S6K1 activation in adult cardiac myocytes following hypertrophic stimulation. PMID:17976640

  4. Regulation of mTOR and S6K1 activation by the nPKC isoforms, PKCepsilon and PKCdelta, in adult cardiac muscle cells.

    PubMed

    Moschella, Phillip C; Rao, Vijay U; McDermott, Paul J; Kuppuswamy, Dhandapani

    2007-12-01

    Activation of both mTOR and its downstream target, S6K1 (p70 S6 kinase) have been implicated to affect cardiac hypertrophy. Our earlier work, in a feline model of 1-48 h pressure overload, demonstrated that mTOR/S6K1 activation occurred primarily through a PKC/c-Raf pathway. To further delineate the role of specific PKC isoforms on mTOR/S6K1 activation, we utilized primary cultures of adult feline cardiomyocytes in vitro and stimulated with endothelin-1 (ET-1), phenylephrine (PE), TPA, or insulin. All agonist treatments resulted in S2248 phosphorylation of mTOR and T389 and S421/T424 phosphorylation of S6K1, however only ET-1 and TPA-stimulated mTOR/S6K1 activation was abolished with infection of a dominant negative adenoviral c-Raf (DN-Raf) construct. Expression of DN-PKC(epsilon) blocked ET-1-stimulated mTOR S2448 and S6K1 S421/T424 and T389 phosphorylation but had no effect on insulin-stimulated S6K1 phosphorylation. Expression of DN-PKC(delta) or pretreatment of cardiomyocytes with rottlerin, a PKC(delta) specific inhibitor, blocked both ET-1 and insulin stimulated mTOR S2448 and S6K1 T389 phosphorylation. However, treatment with Gö6976, a specific classical PKC (cPKC) inhibitor did not affect mTOR/S6K1 activation. These data indicate that: (i) PKC(epsilon) is required for ET-1-stimulated T421/S424 phosphorylation of S6K1, (ii) both PKC(epsilon) and PKC(delta) are required for ET-1-stimulated mTOR S2448 and S6K1 T389 phosphorylation, (iii) PKC(delta) is also required for insulin-stimulated mTOR S2448 and S6K1 T389 phosphorylation. Together, these data delineate both distinct and combinatorial roles of specific PKC isoforms on mTOR and S6K1 activation in adult cardiac myocytes following hypertrophic stimulation.

  5. Preclinical and clinical development of a YFV 17 D-based chimeric vaccine against West Nile virus.

    PubMed

    Dayan, Gustavo H; Pugachev, Konstantin; Bevilacqua, Joan; Lang, Jean; Monath, Thomas P

    2013-12-09

    Substantial success has been achieved in the development and implementation of West Nile (WN) vaccines for horses; however, no human WN vaccines are approved. This review focuses on the construction, pre-clinical and clinical characterization of ChimeriVax-WN02 for humans, a live chimeric vaccine composed of a yellow fever (YF) 17D virus in which the prM-E envelope protein genes are replaced with the corresponding genes of the WN NY99 virus. Pre-clinical studies demonstrated that ChimeriVax-WN02 was significantly less neurovirulent than YF 17D in mice and rhesus and cynomolgus monkeys. The vaccine elicited neutralizing antibody titers after inoculation in hamsters and monkeys and protected immunized animals from lethal challenge including intracerebral inoculation of high dose of WN NY99 virus. Safety, viremia and immunogenicity of ChimeriVax-WN02 were assessed in one phase I study and in two phase II clinical trials. No safety signals were detected in the three clinical trials with no remarkable differences in incidence of adverse events (AEs) between vaccine and placebo recipients. Viremia was transient and the mean viremia levels were low. The vaccine elicited strong and durable neutralizing antibody and cytotoxic T cell responses. WN epidemiology impedes a classical licensure pathway; therefore, innovative licensure strategies should be explored.

  6. c-Raf/MEK/ERK pathway controls protein kinase C-mediated p70S6K activation in adult cardiac muscle cells.

    PubMed

    Iijima, Yoshihiro; Laser, Martin; Shiraishi, Hirokazu; Willey, Christopher D; Sundaravadivel, Balasubramanian; Xu, Lin; McDermott, Paul J; Kuppuswamy, Dhandapani

    2002-06-21

    p70S6 kinase (S6K1) plays a pivotal role in hypertrophic cardiac growth via ribosomal biogenesis. In pressure-overloaded myocardium, we show S6K1 activation accompanied by activation of protein kinase C (PKC), c-Raf, and mitogen-activated protein kinases (MAPKs). To explore the importance of the c-Raf/MAPK kinase (MEK)/MAPK pathway, we stimulated adult feline cardiomyocytes with 12-O-tetradecanoylphorbol-13-acetate (TPA), insulin, or forskolin to activate PKC, phosphatidylinositol-3-OH kinase, or protein kinase A (PKA), respectively. These treatments resulted in S6K1 activation with Thr-389 phosphorylation as well as mammalian target of rapamycin (mTOR) and S6 protein phosphorylation. Thr-421/Ser-424 phosphorylation of S6K1 was observed predominantly in TPA-treated cells. Dominant negative c-Raf expression or a MEK1/2 inhibitor (U0126) treatment showed a profound blocking effect only on the TPA-stimulated phosphorylation of S6K1 and mTOR. Whereas p38 MAPK inhibitors exhibited only partial effect, MAPK-phosphatase-3 expression significantly blocked the TPA-stimulated S6K1 and mTOR phosphorylation. Inhibition of mTOR with rapamycin blocked the Thr-389 but not the Thr-421/Ser-424 phosphorylation of S6K1. Therefore, during PKC activation, the c-Raf/MEK/extracellular signal-regulated kinase-1/2 (ERK1/2) pathway mediates both the Thr-421/Ser-424 and the Thr-389 phosphorylation in an mTOR-independent and -dependent manner, respectively. Together, our in vivo and in vitro studies indicate that the PKC/c-Raf/MEK/ERK pathway plays a major role in the S6K1 activation in hypertrophic cardiac growth.

  7. Importance of preclinical evaluation of wear in hip implant designs using simulator machines.

    PubMed

    Trommer, Rafael Mello; Maru, Márcia Marie

    2017-01-01

    Total hip arthroplasty (THA) is a surgical procedure that involves the replacement of the damaged joint of the hip by an artificial device. Despite the recognized clinical success of hip implants, wear of the articulating surfaces remains as one of the critical issues influencing performance. Common material combinations used in hip designs comprise metal-on-polymer (MoP), ceramic-on-polymer (CoP), metal-on-metal (MoM), and ceramic-on-ceramic (CoC). However, when the design of the hip implant is concerned besides the materials used, several parameters can influence its wear performance. In this scenario, where the safety and efficacy for the patient are the main issues, it is fundamental to evaluate and predict the wear rate of the hip implant design before its use in THA. This is one of the issues that should be taken into account in the preclinical evaluation step of the product, in which simulated laboratory tests are necessary. However, it is fundamental that the applied motions and loads can reproduce the wear mechanisms physiologically observed in the patient. To replicate the in vivo angular displacements and loadings, special machines known as joint simulators are employed. This article focuses on the main characteristics related to the wear simulation of hip implants using mechanical simulators, giving information to surgeons, researchers, regulatory bodies, etc., about the importance of preclinical wear evaluation. A critical analysis is performed on the differences in the principles of operation of simulators and their effects on the final results, and about future trends in wear simulation.

  8. Pre-clinical development of a hydrogen peroxide-inactivated West Nile virus vaccine.

    PubMed

    Poore, Elizabeth A; Slifka, Dawn K; Raué, Hans-Peter; Thomas, Archana; Hammarlund, Erika; Quintel, Benjamin K; Torrey, Lindsay L; Slifka, Ariel M; Richner, Justin M; Dubois, Melissa E; Johnson, Lawrence P; Diamond, Michael S; Slifka, Mark K; Amanna, Ian J

    2017-01-05

    West Nile virus (WNV) is a mosquito-transmitted pathogen with a wide geographical range that can lead to long-term disability and death in some cases. Despite the public health risk posed by WNV, including an estimated 3 million infections in the United States alone, no vaccine is available for use in humans. Here, we present a scaled manufacturing approach for production of a hydrogen peroxide-inactivated whole virion WNV vaccine, termed HydroVax-001WNV. Vaccination resulted in robust virus-specific neutralizing antibody responses and protection against WNV-associated mortality in mice or viremia in rhesus macaques (RM). A GLP-compliant toxicology study performed in rats demonstrated an excellent safety profile with clinical findings limited to minor and transient irritation at the injection site. An in vitro relative potency (IVRP) assay was developed and shown to correlate with in vivo responses following forced degradation studies. Long-term in vivo potency comparisons between the intended storage condition (2-8°C) and a thermally stressed condition (40±2°C) demonstrated no loss in vaccine efficacy or protective immunity over a 6-month span of time. Together, the positive pre-clinical findings regarding immunogenicity, safety, and stability indicate that HydroVax-001WNV is a promising vaccine candidate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Selexipag in Pulmonary Arterial Hypertension: Most Updated Evidence From Recent Preclinical and Clinical Studies.

    PubMed

    Ghosh, Raktim K; Ball, Somedeb; Das, Avash; Bandyopadhyay, Dhrubajyoti; Mondal, Samhati; Saha, Debjit; Gupta, Anjan

    2017-05-01

    Pulmonary arterial hypertension (PAH) is a relatively rare disease that, due to its chronic nature, has always been difficult to treat effectively. Selexipag is an oral prostacyclin (PGI 2 ) agonist that was approved by US Food and Drug Administration (US FDA) in December 2015 for the treatment of PAH. After its success in phase 1 and phase 2 clinical trials regarding the convenient oral twice-daily dosing and low side-effect profile, selexipag raised the hope of controlling the disease progression in PAH patients. In the recently completed multicentered phase 3 study (GRIPHON), selexipag has been shown to reduce death and hospitalization due to PAH significantly, an effect that was consistent across different ranges of maintenance dose. In the same study selexipag use was also associated with an increase in 6-minute walk distance (a measure of symptom severity) from baseline, but no significant improvement in all-cause mortality could be observed. The results of the ongoing phase 3 studies (TRITON and TRANSIT-1) are expected to throw some more light on the safety and efficacy of this novel molecule across various treatment scenarios. Hence, our article aims to summarize all the available information from preclinical and clinical studies published to date on the pharmacodynamics, pharmacokinetics, efficacy, safety (in general and in scenarios such as hepatic and renal function impairment), significant drug interactions (with warfarin and antiretroviral drugs), and clinical significance of oral selexipag in patients with PAH. © 2016, The American College of Clinical Pharmacology.

  10. [Protein kinase A inhibitor H-89 blocks polyploidization of SP600125-induced CMK cells by regulating phosphorylation of ribosomal protein S6 kinase 1].

    PubMed

    Zhao, Song; Yang, Jingang; Li, Changling; Xing, Sining; Yu, Ying; Liu, Shuo; Pu, Feifei; Ma, Dongchu

    2016-10-01

    Objective To investigate the regulatory effect of post-translation modification of ribosomal protein S6 kinase 1 (S6K1) on the polyploidization of megakaryocytes. Methods SP600125, a c-Jun N-terminal kinase (JNK) inhibitor, and H-89, a cAMP-dependent protein kinase (PKA) inhibitor, were used to treat CMK cells separately or in combination. With propidium iodide (PI) to dye DNA in the treated cells, the relative DNA content was detected by flow cytometry, and then the DNA polyploidy was analyzed. The change of expression and phosphorylation of ribosomal protein S6 kinase 1 (S6K1), an important mammalian target of rapamycin (mTOR) downstream target molecule, was analyzed by Western blotting. Molecular docking study and kinase activity assay were performed to analyze the combination of H-89 with S6K1 and the effect of H-89 on the activity of S6K1 kinase. Results SP600125 induced CMK cell polyploidization in a time-dependent and dose-dependent manner. At the same time, it increased the phosphorylation of S6K1 at Thr421/Ser424 and decreased the phosphorylation of S6K1 at Thr389. H-89 not only blocked polyploidization, but also decreased the phosphorylation of S6K1 at Thr421/Ser424 and increased the phosphorylation of S6K1 at Thr389. Molecular docking and kinase activity assay showed that H-89 occupied the ATP binding sites of S6K1 and inhibited its activity. Noticeably, both H-89 and SP600125 inhibited the activity of PKA. Moreover, the two drugs further inhibited the activity of PKA when used together. Therefore, these data indicated that H-89 blocked the SP600125-induced polyploidization of CMK cells mainly by changing S6K1 phosphorylation state, rather than its inhibitory effect on PKA. Conclusion H-89 can block the polyploidization of SP600125-induced CMK cells by regulating S6K1 phosphorylation state.

  11. Agmatine potentiates neuroprotective effects of subthreshold concentrations of ketamine via mTOR/S6 kinase signaling pathway.

    PubMed

    Tavares, Mauren K; Dos Reis, Suellen; Platt, Nicolle; Heinrich, Isabella A; Wolin, Ingrid A V; Leal, Rodrigo B; Kaster, Manuella P; Rodrigues, Ana Lúcia S; Freitas, Andiara E

    2018-05-12

    Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is one of the most robust neurobiological findings in the pathophysiology of major depressive disorder (MDD) over the last 40 years. The persistent increase in glucocorticoids levels induces morphological and anatomical changes in the brain, especially in the hippocampus. Ketamine represents a major advance for the treatment of MDD, however the psychotomimetic effects of this compound limit its widespread use. Agmatine is a neuromodulator that has been shown to be a putative novel and well-tolerated antidepressant/augmenter drug. In this study, the exposure of HT22 hippocampal neuronal cell line to corticosterone (50 μM) induced a significant neuronal cell death. Interestingly, the incubation of HT22 cells with the fast-acting antidepressant drug ketamine (1 μM) prevented the corticosterone-induced toxicity. Similarly, agmatine caused a significant cytoprotection at the concentration of 0.1 μM against corticosterone (50 μM) cell damage. Notably, the incubation with a subthreshold concentration of ketamine (0.01 μM) in combination with a subthreshold concentration of agmatine (0.001 μM) prevented the neuronal damage elicited by corticosterone (50 μM). A 24 h co-incubation with subthreshold concentrations of ketamine (0.01 μM) and agmatine (0.001 μM) was able to cause a significant increase in the phosphorylation levels of Akt (Ser 473 ) and p70S6 kinase (Thr 389 ) as well as PSD95 immunocontent. Neither glycogen synthase kinase-3β (Ser 9 ) phosphorylation nor β catenin immunocontent were altered by a 24 h co-incubation period. Finally, the co-incubation of cells for 30 min did not produce any effect in the phosphorylation or immunocontent of any protein investigated. Taken together, our results support the notion that the combination of subthreshold concentrations of ketamine and agmatine has cytoprotective effects against corticosterone-induced cell death. This effect

  12. Ribosomal S6K1 in POMC and AgRP Neurons Regulates Glucose Homeostasis but Not Feeding Behavior in Mice

    PubMed Central

    Smith, Mark A.; Katsouri, Loukia; Irvine, Elaine E.; Hankir, Mohammed K.; Pedroni, Silvia M.A.; Voshol, Peter J.; Gordon, Matthew W.; Choudhury, Agharul I.; Woods, Angela; Vidal-Puig, Antonio; Carling, David; Withers, Dominic J.

    2015-01-01

    Summary Hypothalamic ribosomal S6K1 has been suggested as a point of convergence for hormonal and nutrient signals in the regulation of feeding behavior, bodyweight, and glucose metabolism. However, the long-term effects of manipulating hypothalamic S6K1 signaling on energy homeostasis and the cellular mechanisms underlying these roles are unclear. We therefore inactivated S6K1 in pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, but in contrast to the current view, we found no evidence that S6K1 regulates food intake and bodyweight. In contrast, S6K1 signaling in POMC neurons regulated hepatic glucose production and peripheral lipid metabolism and modulated neuronal excitability. S6K1 signaling in AgRP neurons regulated skeletal muscle insulin sensitivity and was required for glucose sensing by these neurons. Our findings suggest that S6K1 signaling is not a general integrator of energy homeostasis in the mediobasal hypothalamus but has distinct roles in the regulation of glucose homeostasis by POMC and AgRP neurons. PMID:25865886

  13. Ribosomal S6K1 in POMC and AgRP Neurons Regulates Glucose Homeostasis but Not Feeding Behavior in Mice.

    PubMed

    Smith, Mark A; Katsouri, Loukia; Irvine, Elaine E; Hankir, Mohammed K; Pedroni, Silvia M A; Voshol, Peter J; Gordon, Matthew W; Choudhury, Agharul I; Woods, Angela; Vidal-Puig, Antonio; Carling, David; Withers, Dominic J

    2015-04-21

    Hypothalamic ribosomal S6K1 has been suggested as a point of convergence for hormonal and nutrient signals in the regulation of feeding behavior, bodyweight, and glucose metabolism. However, the long-term effects of manipulating hypothalamic S6K1 signaling on energy homeostasis and the cellular mechanisms underlying these roles are unclear. We therefore inactivated S6K1 in pro-opiomelanocortin (POMC) and agouti-related protein (AgRP) neurons, key regulators of energy homeostasis, but in contrast to the current view, we found no evidence that S6K1 regulates food intake and bodyweight. In contrast, S6K1 signaling in POMC neurons regulated hepatic glucose production and peripheral lipid metabolism and modulated neuronal excitability. S6K1 signaling in AgRP neurons regulated skeletal muscle insulin sensitivity and was required for glucose sensing by these neurons. Our findings suggest that S6K1 signaling is not a general integrator of energy homeostasis in the mediobasal hypothalamus but has distinct roles in the regulation of glucose homeostasis by POMC and AgRP neurons. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Characteristics of strong motions and damage implications of M S6.5 Ludian earthquake on August 3, 2014

    NASA Astrophysics Data System (ADS)

    Xu, Peibin; Wen, Ruizhi; Wang, Hongwei; Ji, Kun; Ren, Yefei

    2015-02-01

    The Ludian County of Yunnan Province in southwestern China was struck by an M S6.5 earthquake on August 3, 2014, which was another destructive event following the M S8.0 Wenchuan earthquake in 2008, M S7.1 Yushu earthquake in 2010, and M S7.0 Lushan earthquake in 2013. National Strong-Motion Observation Network System of China collected 74 strong motion recordings, which the maximum peak ground acceleration recorded by the 053LLT station in Longtoushan Town was 949 cm/s2 in E-W component. The observed PGAs and spectral ordinates were compared with ground-motion prediction equation in China and the NGA-West2 developed by Pacific Earthquake Engineering Researcher Center. This earthquake is considered as the first case for testing applicability of NGA-West2 in China. Results indicate that the observed PGAs and the 5 % damped pseudo-response spectral accelerations are significantly lower than the predicted ones. The field survey around some typical strong motion stations verified that the earthquake damage was consistent with the official isoseismal by China Earthquake Administration.

  15. Quantitation of intracellular metabolites of [35S]-6-mercaptopurine in L5178Y cells grown in time-course incubates.

    PubMed

    Breter, H J; Zahn, R K

    1979-09-01

    6-Mercaptopurine (6MP) metabolism was quantitatively determined in L5178Y murine lymphoma. Cells grown in time-course incubates with [35S]-6MP were extracted with cold perchloric acid, and the buffered extracts were subjected to high-performance liquid cation-exchange chromatography prior to and after hydrolysis with alkaline phosphatase. Free sulfate, 6-thiouric acid, 6-thioxanthosine, 6-thioguanosine, 6-thioinosine, free 6MP, and 6-methylthioinosine were separated from each other; identified in the radiochromatograms by elution volume, UV spectroscopic data, and enzymatic peak-shifting analyses with purine nucleoside phosphorylase; and quantitatively determined by means of 35S radioactivity. Gross intracellular 35S concentrations remained constant at 5 x 10(-5) M after 1 hr of incubation. 6MP metabolism in L5178Y cells was distinguished into an early phase (to 1 hr of incubation) in which 6MP was predominantly catabolized to 6-thiouric acid and free sulfate, into an intermediate phase (to 8 hr) in which substantial amounts of free 6MP and of ribonucleotides of 6-thioxanthosine and 6-thioguanosine were present while the concentrations of nonnucleotide oxidation products sharply decreased, and into a late phase (to 24 hr) in which the ribonucleotides of 6MP, of 6-thioguanosine and, in particular, of 6-methylthioinosine were the most abundant metabolites.

  16. Warped AdS 6 × S 2 in Type IIB supergravity III. Global solutions with seven-branes

    NASA Astrophysics Data System (ADS)

    D'Hoker, Eric; Gutperle, Michael; Uhlemann, Christoph F.

    2017-11-01

    We extend our previous construction of global solutions to Type IIB super-gravity that are invariant under the superalgebra F(4) and are realized on a spacetime of the form AdS 6 × S 2 warped over a Riemann surface Σ by allowing the supergravity fields to have non-trivial SL(2, ℝ) monodromy at isolated punctures on Σ. We obtain explicit solutions for the case where Σ is a disc, and the monodromy generators are parabolic elements of SL(2, ℝ) physically corresponding to the monodromy allowed in Type IIB string theory. On the boundary of Σ the solutions exhibit singularities at isolated points which correspond to semi-infinite five-branes, as is familiar from the global solutions without monodromy. In the interior of Σ, the solutions are everywhere regular, except at the punctures where SL(2, ℝ) monodromy resides and which physically correspond to the locations of [ p, q] seven-branes. The solutions have a compelling physical interpretation corresponding to fully localized five-brane intersections with additional seven-branes, and provide candidate holographic duals to the five-dimensional superconformal field theories realized on such intersections.

  17. Pentanuclear Cyanide-Bridged Complexes with High Spin Ground States S=6 and 9: Characterization and Magnetic Properties

    NASA Astrophysics Data System (ADS)

    Marvilliers, Arnaud; Hortholary, Cédric; Rogez, Guillaume; Audière, Jean-Paul; Rivière, Eric; Cano Boquera, Joan; Paulsen, Carley; Villar, Vincent; Mallah, Talal

    2001-07-01

    Two pentanuclear complexes are obtained from the reaction of hexacyanochromate(III) with one to two molar equivalents of [Ni(H2O)6]2+ and bidentate organic ligands that chelate the metal ion, leaving two coordination sites in cis positions. Even though the crystal structure was not solved, the full characterization supports the formation of pentanuclear discrete species. [Cr(CN)6]2[Ni(HIM2-py)2]3·7H2O, 1, has a ground spin state S=6 owing to the ferromagnetic interaction between CrIII (S=3/2) and NII (S=1). The presence of six organic radicals that couple ferromagnetically with NiII in [Cr(CN)6]2[Ni(IM2-py)2]3·7H2O, 2, leads to an S=9 ground state. A.c. susceptibility measurements below 2K indicate the occurrence of an antiferromagnetic order at 1.5 K in 2.

  18. Reducing Ribosomal Protein S6 Kinase 1 Expression Improves Spatial Memory and Synaptic Plasticity in a Mouse Model of Alzheimer's Disease

    PubMed Central

    Caccamo, Antonella; Branca, Caterina; Talboom, Joshua S.; Shaw, Darren M.; Turner, Dharshaun; Ma, Luyao; Messina, Angela; Huang, Zebing; Wu, Jie

    2015-01-01

    Aging is the most important risk factor associated with Alzheimer's disease (AD); however, the molecular mechanisms linking aging to AD remain unclear. Suppression of the ribosomal protein S6 kinase 1 (S6K1) increases healthspan and lifespan in several organisms, from nematodes to mammals. Here we show that S6K1 expression is upregulated in the brains of AD patients. Using a mouse model of AD, we found that genetic reduction of S6K1 improved synaptic plasticity and spatial memory deficits, and reduced the accumulation of amyloid-β and tau, the two neuropathological hallmarks of AD. Mechanistically, these changes were linked to reduced translation of tau and the β-site amyloid precursor protein cleaving enzyme 1, a key enzyme in the generation of amyloid-β. Our results implicate S6K1 dysregulation as a previously unidentified molecular mechanism underlying synaptic and memory deficits in AD. These findings further suggest that therapeutic manipulation of S6K1 could be a valid approach to mitigate AD pathology. SIGNIFICANCE STATEMENT Aging is the most important risk factor for Alzheimer's disease (AD). However, little is known about how it contributes to AD pathogenesis. S6 kinase 1 (S6K1) is a protein kinase involved in regulation of protein translation. Reducing S6K1 activity increases lifespan and healthspan. We report the novel finding that reducing S6K1 activity in 3xTg-AD mice ameliorates synaptic and cognitive deficits. These improvement were associated with a reduction in amyloid-β and tau pathology. Mechanistically, lowering S6K1 levels reduced translation of β-site amyloid precursor protein cleaving enzyme 1 and tau, two key proteins involved in AD pathogenesis. These data suggest that S6K1 may represent a molecular link between aging and AD. Given that aging is the most important risk factor for most neurodegenerative diseases, our results may have far-reaching implications into other diseases. PMID:26468204

  19. Transcriptional Responses Reveal Similarities Between Preclinical Rat Liver Testing Systems.

    PubMed

    Liu, Zhichao; Delavan, Brian; Roberts, Ruth; Tong, Weida

    2018-01-01

    Toxicogenomics (TGx) is an important tool to gain an enhanced understanding of toxicity at the molecular level. Previously, we developed a pair ranking (PRank) method to assess in vitro to in vivo extrapolation (IVIVE) using toxicogenomic datasets from the Open Toxicogenomics Project-Genomics Assisted Toxicity Evaluation System (TG-GATEs) database. With this method, we investiagted three important questions that were not addressed in our previous study: (1) is a 1-day in vivo short-term assay able to replace the 28-day standard and expensive toxicological assay? (2) are some biological processes more conservative across different preclinical testing systems than others? and (3) do these preclinical testing systems have the similar resolution in differentiating drugs by their therapeutic uses? For question 1, a high similarity was noted (PRank score = 0.90), indicating the potential utility of shorter term in vivo studies to predict outcome in longer term and more expensive in vivo model systems. There was a moderate similarity between rat primary hepatocytes and in vivo repeat-dose studies (PRank score = 0.71) but a low similarity (PRank score = 0.56) between rat primary hepatocytes and in vivo single dose studies. To address question 2, we limited the analysis to gene sets relevant to specific toxicogenomic pathways and we found that pathways such as lipid metabolism were consistently over-represented in all three assay systems. For question 3, all three preclinical assay systems could distinguish compounds from different therapeutic categories. This suggests that any noted differences in assay systems was biological process-dependent and furthermore that all three systems have utility in assessing drug responses within a certain drug class. In conclusion, this comparison of three commonly used rat TGx systems provides useful information in utility and application of TGx assays.

  20. Collaborative learning in pre-clinical dental hygiene education.

    PubMed

    Mueller-Joseph, Laura J; Nappo-Dattoma, Luisa

    2013-04-01

    Dental hygiene education continues to move beyond mastery of content material and skill development to learning concepts that promote critical-thinking and problem-solving skills. The purpose of this research was to evaluate the effectiveness of collaborative learning and determine the growth in intellectual development of 54 first-year dental hygiene students. The control group used traditional pre-clinical teaching and the experimental group used collaborative pedagogy for instrument introduction. All students were subjected to a post-test evaluating their ability to apply the principles of instrumentation. Intellectual development was determined using pre- and post-tests based on the Perry Scheme of Intellectual Development. Student attitudes were assessed using daily Classroom Assessment Activities and an end-of-semester departmental course evaluation. Findings indicated no significant difference between collaborative learning and traditional learning in achieving pre-clinical competence as evidenced by the students' ability to apply the principles of instrumentation. Advancement in intellectual development did not differ significantly between groups. Value added benefits of a collaborative learning environment as identified by the evaluation of student attitudes included decreased student reliance on authority, recognition of peers as legitimate sources of learning and increased self-confidence. A significant difference in student responses to daily classroom assessments was evident on the 5 days a collaborative learning environment was employed. Dental hygiene students involved in a pre-clinical collaborative learning environment are more responsible for their own learning and tend to have a more positive attitude toward the subject matter. Future studies evaluating collaborative learning in clinical dental hygiene education need to investigate the cost/benefit ratio of the value added outcomes of collaborative learning.

  1. Integrating Ultrasound Teaching into Preclinical Problem-based Learning

    PubMed Central

    Tshibwabwa, Eli Tumba; Cannon, Jenifer; Rice, James; Kawooya, Michael G; Sanii, Reza; Mallin, Robert

    2016-01-01

    Objectives: The aim is to provide students in the preclinical with ultrasound image interpretation skills. Research question: Are students in smaller groups with access to a combination of lectures and hands-on patient contact most likely to have better ultrasound image interpretation skills, than students in larger groups with only interactive didactic lectures? Methodology: First-year students at the preclinical Program of the College of Medicine, participated in two 2-h introductory interactive ultrasound sessions. The study comprised two cohorts: 2012/2013 students, who were offered large group teaching (LGT) sessions (control group), and 2013/2014 students, who received the intervention in small group learning problem-based learning (PBL) sessions (experimental group). The overall learning objectives were identical for both groups. The success of the module was evaluated using pre- and post-tests as well as students’ feedback. Results: The students in the experimental group showed significantly higher scores in interpretations of images than those in the control group. The experimental group showed achievement of learning outcomes along with higher levels of satisfaction with the module compared to the latter. Conclusion: Posttest knowledge of the basics of ultrasound improved significantly over the pretest in the experimental group. In addition, students’ overall satisfaction of the ultrasound module was shown to be higher for the PBL compared to the LGT groups. Small groups in an interactive and PBL setting along with opportunities for hands-on practice and simultaneous visualization of findings on a high definition screen should enhance preclinical student learning of the basics of ultrasound. Despite the potential of ultrasound as a clinical, teaching and learning tool for students in the preclinical years, standardized recommendations have yet to be created regarding its integration into the curricula within academic institutions and clinical medicine

  2. 3D laser optoacoustic ultrasonic imaging system for preclinical research

    NASA Astrophysics Data System (ADS)

    Ermilov, Sergey A.; Conjusteau, André; Hernandez, Travis; Su, Richard; Nadvoretskiy, Vyacheslav; Tsyboulski, Dmitri; Anis, Fatima; Anastasio, Mark A.; Oraevsky, Alexander A.

    2013-03-01

    In this work, we introduce a novel three-dimensional imaging system for in vivo high-resolution anatomical and functional whole-body visualization of small animal models developed for preclinical or other type of biomedical research. The system (LOUIS-3DM) combines a multi-wavelength optoacoustic and ultrawide-band laser ultrasound tomographies to obtain coregistered maps of tissue optical absorption and acoustic properties, displayed within the skin outline of the studied animal. The most promising applications of the LOUIS-3DM include 3D angiography, cancer research, and longitudinal studies of biological distribution of optoacoustic contrast agents (carbon nanotubes, metal plasmonic nanoparticles, etc.).

  3. [Preclinical birth of an extremely premature infant - a case report].

    PubMed

    Pöhlmann, Tobias; Schmidt, Armin; Pohl, Wolfgang

    2016-11-01

    Obstetrical emergencies requiring emergency medical service are very rare. An extremely premature birth in a preclinical setting is certainly exceptional. In the following case report, the emergency medical team was unexpectedly faced with the home birth of a fetus at the 23 rd week of gestation. Prematurity at the edge of viability poses a challenge to first care, equipment, infrastructure, expertise and clinical ethics. To the authors' knowledge, there is no comparable case report published so far. © Georg Thieme Verlag Stuttgart · New York.

  4. [Preclinical treatment of multiple trauma : what is important?].

    PubMed

    Schweigkofler, U; Hoffmann, R

    2013-09-01

    Multiple trauma is still the most common cause of death in the age group below 40 years but rarely occurs in prehospital emergencies in Germany. Therefore, personal experience of emergency physicians in prehospital treatment of multiple trauma is often limited. Priority-based therapy according to standardized algorithms and advances in clinical and intensive care have reduced hospital mortality down to 13 %. Time factors, treatment and transport by Helicopter Emergency Medical Services seem to have had a significant impact on the outcome. The current German multiple trauma S3 guidelines provide algorithms for preclinical treatment. The underlying scientific evidence in this respect is, however, low.

  5. Preclinical QSP Modeling in the Pharmaceutical Industry: An IQ Consortium Survey Examining the Current Landscape

    PubMed Central

    Wu, Fan; Bansal, Loveleena; Bradshaw‐Pierce, Erica; Chan, Jason R.; Liederer, Bianca M.; Mettetal, Jerome T.; Schroeder, Patricia; Schuck, Edgar; Tsai, Alice; Xu, Christine; Chimalakonda, Anjaneya; Le, Kha; Penney, Mark; Topp, Brian; Yamada, Akihiro

    2018-01-01

    A cross‐industry survey was conducted to assess the landscape of preclinical quantitative systems pharmacology (QSP) modeling within pharmaceutical companies. This article presents the survey results, which provide insights on the current state of preclinical QSP modeling in addition to future opportunities. Our results call attention to the need for an aligned definition and consistent terminology around QSP, yet highlight the broad applicability and benefits preclinical QSP modeling is currently delivering. PMID:29349875

  6. Silencing of Tuberin Enhances Photoreceptor Survival and Function in a Preclinical Model of Retinitis Pigmentosa (An American Ophthalmological Society Thesis)

    PubMed Central

    Tsang, Stephen H.; Chan, Lawrence; Tsai, Yi-Ting; Wu, Wen-Hsuan; Hsu, Chun-Wei; Yang, Jin; Tosi, Joaquin; Wert, Katherine J.; Davis, Richard J.; Mahajan, Vinit B.

    2014-01-01

    Purpose: To assess the functional consequences of silencing of tuberin, an inhibitor of the mTOR signaling pathway, in a preclinical model of retinitis pigmentosa (RP) in order to test the hypothesis that insufficient induction of the protein kinase B (PKB)-regulated tuberin/mTOR self-survival pathway initiates apoptosis. Methods: In an unbiased genome-scale approach, kinase peptide substrate arrays were used to analyze self-survival pathways at the onset of photoreceptor degeneration. The mutant Pde6bH620Q/Pde6bH620Q at P14 and P18 photoreceptor outer segment (OS) lysates were labeled with P-ATP and hybridized to an array of 1,164 different synthetic peptide substrates. At this stage, OS of Pde6bH620Q/Pde6bH620Q rods are morphologically normal. In vitro kinase assays and immunohistochemistry were used to validate phosphorylation. Short hairpin RNA (shRNA) gene silencing was used to validate tuberin’s role in regulating survival. Results: At the onset of degeneration, 162 peptides were differentially phosphorylated. Protein kinases A, G, C (AGC kinases), and B exhibited increased activity in both peptide array and in vitro kinase assays. Immunohistochemical data confirmed altered phosphorylation patterns for phosphoinositide-dependent kinase-1 (PDK1), ribosomal protein S6 (RPS6), and tuberin. Tuberin gene silencing rescued photoreceptors from degeneration. Conclusions: Phosphorylation of tuberin and RPS6 is due to the upregulated activity of PKB. PKB/tuberin cell growth/survival signaling is activated before the onset of degeneration. Substrates of the AGC kinases in the PKB/tuberin pathway are phosphorylated to promote cell survival. Knockdown of tuberin, the inhibitor of the mTOR pathway, increased photoreceptor survival and function in a preclinical model of RP. PMID:25646031

  7. Regulation of androgen receptor transactivity and mTOR-S6 kinase pathway by Rheb in prostate cancer cell proliferation.

    PubMed

    Kobayashi, Takashi; Shimizu, Yosuke; Terada, Naoki; Yamasaki, Toshinari; Nakamura, Eijiro; Toda, Yoshinobu; Nishiyama, Hiroyuki; Kamoto, Toshiyuki; Ogawa, Osamu; Inoue, Takahiro

    2010-06-01

    Ras homolog-enriched in brain (Rheb), a small GTP-binding protein, is associated with prostate carcinogenesis through activating mammalian target of rapamycin (mTOR) signaling pathway. This study aimed to elucidate whether Rheb promotes proliferation of prostate cancer cells and can act as a potent therapeutic target in prostate cancer. Prostate cancer cell lines and human prostatic tissues were examined for the expression of Rheb. The effects of forced expression or knockdown of Rheb on cell proliferation were also examined. Semi-quantitative and quantitative RT-PCR were performed to evaluate mRNA expression. Western blotting was used to examine protein expression. Cell count and WST-1 assay were used to measure cell proliferation. Fluorescence-activated cell sorting was used to assess the cell cycle. Rheb mRNA and protein expression was higher in more aggressive, androgen-independent prostate cancer cell lines PC3, DU145, and C4-2, compared with the less aggressive LNCaP. Rheb expression was higher in cancer tissues than in benign prostatic epithelia. Forced expression of Rheb in LNCaP cells accelerated proliferation without enhancing androgen receptor transactivity. Attenuation of Rheb expression or treatment with the mTOR inhibitor rapamycin decreased proliferation of PC3 and DU145 cells, with a decrease in the activated form of p70S6 kinase, one of the main targets of mTOR. Rheb potentiates proliferation of prostate cancer cells and inhibition of Rheb or mTOR can lead to suppressed proliferation of aggressive prostate cancer cell lines in vitro. Rheb and the mTOR pathway are therefore probable targets for suppressing prostate cancer.

  8. Na+/H+ exchanger isoform 1-induced osteopontin expression facilitates cardiac hypertrophy through p90 ribosomal S6 kinase.

    PubMed

    Abdulrahman, Nabeel; Jaspard-Vinassa, Beatrice; Fliegel, Larry; Jabeen, Aayesha; Riaz, Sadaf; Gadeau, Alain-Pierre; Mraiche, Fatima

    2018-05-01

    Cardiovascular diseases are the leading cause of death worldwide. One in three cases of heart failure is due to dilated cardiomyopathy. The Na + /H + exchanger isoform 1 (NHE1), a multifunctional protein and the key pH regulator in the heart, has been demonstrated to be increased in this condition. We have previously demonstrated that elevated NHE1 activity induced cardiac hypertrophy in vivo. Furthermore, the overexpression of active NHE1 elicited modulation of gene expression in cardiomyocytes including an upregulation of myocardial osteopontin (OPN) expression. To determine the role of OPN in inducing NHE1-mediated cardiomyocyte hypertrophy, double transgenic mice expressing active NHE1 and OPN knockout were generated and assessed by echocardiography and the cardiac phenotype. Our studies showed that hearts expressing active NHE1 exhibited cardiac remodeling indicated by increased systolic and diastolic left ventricular internal diameter and increased ventricular volume. Moreover, these hearts demonstrated impaired function with decreased fractional shortening and ejection fraction. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) mRNA was upregulated, and there was an increase in heart cell cross-sectional area confirming the cardiac hypertrophic effect. Moreover, NHE1 transgenic mice also showed increased collagen deposition, upregulation of CD44 and phosphorylation of p90 ribosomal s6 kinase (RSK), effects that were regressed in OPN knockout mice. In conclusion, we developed an interesting comparative model of active NHE1 transgenic mouse lines which express a dilated hypertrophic phenotype expressing CD44 and phosphorylated RSK, effects which were regressed in absence of OPN.

  9. Positions of the cytoplasmic end of BK α S0 helix relative to S1–S6 and of β1 TM1 and TM2 relative to S0–S6

    PubMed Central

    Liu, Guoxia; Zakharov, Sergey I.; Yao, Yongneng

    2015-01-01

    The large-conductance, voltage- and Ca2+-gated K+ (BK) channel consists of four α subunits, which form a voltage- and Ca2+-gated channel, and up to four modulatory β subunits. The β1 subunit is expressed in smooth muscle, where it slows BK channel kinetics and shifts the conductance–voltage (G-V) curve to the left at [Ca2+] > 2 µM. In addition to the six transmembrane (TM) helices, S1–S6, conserved in all voltage-dependent K+ channels, BK α has a unique seventh TM helix, S0, which may contribute to the unusual rightward shift in the G-V curve of BK α in the absence of β1 and to a leftward shift in its presence. Such a role is supported by the close proximity of S0 to S3 and S4 in the voltage-sensing domain. Furthermore, on the extracellular side of the membrane, one of the two TM helices of β1, TM2, is adjacent to S0. We have now analyzed induced disulfide bond formation between substituted Cys residues on the cytoplasmic side of the membrane. There, in contrast, S0 is closest to the S2–S3 loop, from which position it is displaced on the addition of β1. The cytoplasmic ends of β1 TM1 and TM2 are adjacent and are located between the S2–S3 loop of one α subunit and S1 of a neighboring α subunit and are not adjacent to S0; i.e., S0 and TM2 have different trajectories through the membrane. In the absence of β1, 70% of disulfide bonding of W43C (S0) and L175C (S2–S3) has no effect on V50 for activation, implying that the cytoplasmic end of S0 and the S2–S3 loop move in concert, if at all, during activation. Otherwise, linking them together in one state would obstruct the transition to the other state, which would certainly change V50. PMID:25667410

  10. Predictive value of EGFR-PI3K-pAKT-mTOR-pS6 pathway in sinonasal squamous cell carcinomas.

    PubMed

    Muñoz-Cordero, María Gabriela; López, Fernando; García-Inclán, Cristina; López-Hernández, Alejandro; Potes-Ares, Sira; Fernández-Vañes, Laura; Llorente, José Luis; Hermsen, Mario

    2018-03-21

    We have previously indicated that EGFR has a role in carcinogenesis in a subgroup of sinonasal squamous cell carcinomas (SNSCC). In addition, EGFR activates 2 of the most important intracellular signalling pathways: PI3K/pAKT/mTOR/pS6 and MAP pathway kinases. The objective of this study was to evaluate the involvement of the EGFR/PI3K/pAKT/mTOR/pS6 pathway and its relationship with clinical-pathological parameters and follow-up of sinonasal squamous cell carcinoma. The immunohistochemical expression of different components of the PI3K/AKT/mTOR/pS6 pathway and its relationship with various clinical-pathological parameters was studied in a series of 54 patients with SNSCC. Loss of PTEN expression was observed in 33/54 cases (61%) and pAKT, mTOR and pS6 pre-expression was observed in 19/54 cases (35%), 8/54 cases (15%), and 47/54 cases (87%), respectively. Loss of PTEN expression was related to intracranial invasion and development of regional metastases (p=0.005). Overexpression of pS6 was associated with a decrease in survival (p=0.008), presence of local recurrences (p=0.055), and worsening of overall prognosis (p=0.007). No significant relationships were observed between pAKT and mTOR expression and the clinicopathological parameters studied. Alterations in the expression of EGFR/PI3K/pAKT/mTOR/pS6 pathway components are common in a subgroup of SNSCC. This study reveals that the absence of pS6 overexpression is associated with better clinical outcomes. Therefore, pS6 expression could be considered as an unfavourable prognostic marker. Copyright © 2018. Publicado por Elsevier España, S.L.U.

  11. The case for introducing pre-registered confirmatory pharmacological pre-clinical studies.

    PubMed

    Kiwanuka, Olivia; Bellander, Bo-Michael; Hånell, Anders

    2018-05-01

    When evaluating the design of pre-clinical studies in the field of traumatic brain injury, we found substantial differences compared to phase III clinical trials, which in part may explain the difficulties in translating promising experimental drugs into approved treatments. By using network analysis, we also found cases where a large proportion of the studies evaluating a pre-clinical treatment was performed by inter-related researchers, which is potentially problematic. Subjecting all pre-clinical trials to the rigor of a phase III clinical trial is, however, likely not practically achievable. Instead, we repeat the call for a distinction to be made between exploratory and confirmatory pre-clinical studies.

  12. Drug Safety

    MedlinePlus

    ... over-the-counter drug. The FDA evaluates the safety of a drug by looking at Side effects ... clinical trials The FDA also monitors a drug's safety after approval. For you, drug safety means buying ...

  13. A hepatic amino acid/mTOR/S6K-dependent signalling pathway modulates systemic lipid metabolism via neuronal signals.

    PubMed

    Uno, Kenji; Yamada, Tetsuya; Ishigaki, Yasushi; Imai, Junta; Hasegawa, Yutaka; Sawada, Shojiro; Kaneko, Keizo; Ono, Hiraku; Asano, Tomoichiro; Oka, Yoshitomo; Katagiri, Hideki

    2015-08-13

    Metabolism is coordinated among tissues and organs via neuronal signals. Levels of circulating amino acids (AAs), which are elevated in obesity, activate the intracellular target of rapamycin complex-1 (mTORC1)/S6kinase (S6K) pathway in the liver. Here we demonstrate that hepatic AA/mTORC1/S6K signalling modulates systemic lipid metabolism via a mechanism involving neuronal inter-tissue communication. Hepatic expression of an AA transporter, SNAT2, activates the mTORC1/S6K pathway, and markedly elevates serum triglycerides (TGs), while downregulating adipose lipoprotein lipase (LPL). Hepatic Rheb or active-S6K expression have similar metabolic effects, whereas hepatic expression of dominant-negative-S6K inhibits TG elevation in SNAT2 mice. Denervation, pharmacological deafferentation and β-blocker administration suppress obesity-related hypertriglyceridemia with adipose LPL upregulation, suggesting that signals are transduced between liver and adipose tissue via a neuronal pathway consisting of afferent vagal and efferent sympathetic nerves. Thus, the neuronal mechanism uncovered here serves to coordinate amino acid and lipid levels and contributes to the development of obesity-related hypertriglyceridemia.

  14. Carbachol induces p70S6K1 activation through an ERK-dependent but Akt-independent pathway in human colonic epithelial cells.

    PubMed

    Jiang, Xiaohua; Sinnett-Smith, James; Rozengurt, Enrique

    2009-09-25

    Stimulation of human colonic epithelial T84 cells with the muscarinic receptor agonist carbachol, a stable analog of acetylcholine, induced Akt, p70S6K1 and ERK activation. Treatment of T84 cells with the selective inhibitor of EGF receptor (EGFR) tyrosine kinase AG1478 abrogated Akt phosphorylation on Ser(473) induced by either carbachol or EGF, indicating that carbachol-induced Akt activation is mediated through EGFR transactivation. Surprisingly, AG1478 did not suppress p70S6K1 phosphorylation on Thr(389) in response to carbachol, indicating the G protein-coupled receptor (GPCR) stimulation induces p70S6K1 activation, at least in part, via an Akt-independent pathway. In contrast, treatment with the selective MEK inhibitor U0126 (but not with the inactive analog U0124) inhibited carbachol-induced p70S6K1 activation, indicating that the MEK/ERK/RSK pathway plays a critical role in p70S6K1 activation in GPCR-stimulated T84 cells. These findings imply that GPCR activation induces p70S6K1 via ERK rather than through the canonical PI 3-kinase/Akt/TSC/mTORC1 pathway in T84 colon carcinoma cells.

  15. Carbachol induces p70S6K1 activation through an ERK-dependent but Akt-independent pathway in human colonic epithelial cells

    PubMed Central

    Jiang, Xiaohua; Sinnett-Smith, James; Rozengurt, Enrique

    2009-01-01

    Stimulation of human colonic epithelial T84 cells with the muscarinic receptor agonist carbachol, a stable analog of acetylcholine, induced Akt, p70S6K1 and ERK activation. Treatment of T84 cells with the selective inhibitor of EGF receptor (EGFR) tyrosine kinase AG1478 abrogated Akt phosphorylation on Ser473 induced by either carbachol or EGF, indicating that carbachol-induced Akt activation is mediated through EGFR transactivation. Surprisingly, AG1478 did not suppress p70S6K1 phosphorylation on Thr389 in response to carbachol, indicating the G protein-coupled receptor (GPCR) stimulation induces p70S6K1 activation, at least in part, via an Akt-independent pathway. In contrast, treatment with the selective MEK inhibitor U0126 (but not with the inactive analog U0124) inhibited carbachol-induced p70S6K1 activation, indicating that the MEK/ERK/RSK pathway plays a critical role in p70S6K1 activation in GPCR-stimulated T84 cells. These findings imply that GPCR activation induces p70S6K1 via ERK rather than through the canonical PI 3-kinase/Akt/TSC/mTORC1 pathway in T84 colon carcinoma cells. PMID:19615971

  16. Arterial Calcification in Diabetes Mellitus: Preclinical Models and Translational Implications.

    PubMed

    Stabley, John N; Towler, Dwight A

    2017-02-01

    Diabetes mellitus increasingly afflicts our aging and dysmetabolic population. Type 2 diabetes mellitus and the antecedent metabolic syndrome represent the vast majority of the disease burden-increasingly prevalent in children and older adults. However, type 1 diabetes mellitus is also advancing in preadolescent children. As such, a crushing wave of cardiometabolic disease burden now faces our society. Arteriosclerotic calcification is increased in metabolic syndrome, type 2 diabetes mellitus, and type 1 diabetes mellitus-impairing conduit vessel compliance and function, thereby increasing the risk for dementia, stroke, heart attack, limb ischemia, renal insufficiency, and lower extremity amputation. Preclinical models of these dysmetabolic settings have provided insights into the pathobiology of arterial calcification. Osteochondrogenic morphogens in the BMP-Wnt signaling relay and transcriptional regulatory programs driven by Msx and Runx gene families are entrained to innate immune responses-responses activated by the dysmetabolic state-to direct arterial matrix deposition and mineralization. Recent studies implicate the endothelial-mesenchymal transition in contributing to the phenotypic drift of mineralizing vascular progenitors. In this brief overview, we discuss preclinical disease models that provide mechanistic insights-and point to challenges and opportunities to translate these insights into new therapeutic strategies for our patients afflicted with diabetes mellitus and its arteriosclerotic complications. © 2016 American Heart Association, Inc.

  17. [Docimologic analysis of 4th-year preclinical exam questions].

    PubMed

    Gnagne-Agnero, Koffi N; Zinsou, E M; Assoumou, N M; Adiko, E F

    2003-12-01

    Operative Dentistry and Endodontics' Department of the School of Dentistry of Abidjan experienced pre-clinical exam in fourth year of dentistry with MCQ following guided courses which aim was to lead student to be correctly in charge of the patients when they start their first clinical performance. The objective off his this work is to show how one's can analyse exams questions efficiently. In this work the authors present et discuss the results of the evaluation of this preclinical exam performed through calculation of index of success (Ir) which gives us information on the difficulty of a question for all the students who answered, the discriminative index (Id) which allow to determine when a question is selective enough to distinguish weak to strong students in a group. The mean to evaluate is well chosen because the questions asked has a Ir between 46% et 80% (satisfying Ir) and the average Id is between 0.30 and 0.53 (Id discriminates well among 0.30 et 1). This methodology allows an evaluation of a high number of students by stocked questions.

  18. Sugary beverage intake and preclinical Alzheimer's disease in the community.

    PubMed

    Pase, Matthew P; Himali, Jayandra J; Jacques, Paul F; DeCarli, Charles; Satizabal, Claudia L; Aparicio, Hugo; Vasan, Ramachandran S; Beiser, Alexa S; Seshadri, Sudha

    2017-09-01

    Excess sugar consumption has been linked with Alzheimer's disease (AD) pathology in animal models. We examined the cross-sectional association of sugary beverage consumption with neuropsychological (N = 4276) and magnetic resonance imaging (N = 3846) markers of preclinical Alzheimer's disease and vascular brain injury (VBI) in the community-based Framingham Heart Study. Intake of sugary beverages was estimated using a food frequency questionnaire. Relative to consuming less than one sugary beverage per day, higher intake of sugary beverages was associated with lower total brain volume (1-2/day, β ± standard error [SE] = -0.55 ± 0.14 mean percent difference, P = .0002; >2/day, β ± SE = -0.68 ± 0.18, P < .0001), and poorer performance on tests of episodic memory (all P < .01). Daily fruit juice intake was associated with lower total brain volume, hippocampal volume, and poorer episodic memory (all P < .05). Sugary beverage intake was not associated with VBI in a consistent manner across outcomes. Higher intake of sugary beverages was associated cross-sectionally with markers of preclinical AD. Copyright © 2017 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  19. Experimental design and efficient parameter estimation in preclinical pharmacokinetic studies.

    PubMed

    Ette, E I; Howie, C A; Kelman, A W; Whiting, B

    1995-05-01

    Monte Carlo simulation technique used to evaluate the effect of the arrangement of concentrations on the efficiency of estimation of population pharmacokinetic parameters in the preclinical setting is described. Although the simulations were restricted to the one compartment model with intravenous bolus input, they provide the basis of discussing some structural aspects involved in designing a destructive ("quantic") preclinical population pharmacokinetic study with a fixed sample size as is usually the case in such studies. The efficiency of parameter estimation obtained with sampling strategies based on the three and four time point designs were evaluated in terms of the percent prediction error, design number, individual and joint confidence intervals coverage for parameter estimates approaches, and correlation analysis. The data sets contained random terms for both inter- and residual intra-animal variability. The results showed that the typical population parameter estimates for clearance and volume were efficiently (accurately and precisely) estimated for both designs, while interanimal variability (the only random effect parameter that could be estimated) was inefficiently (inaccurately and imprecisely) estimated with most sampling schedules of the two designs. The exact location of the third and fourth time point for the three and four time point designs, respectively, was not critical to the efficiency of overall estimation of all population parameters of the model. However, some individual population pharmacokinetic parameters were sensitive to the location of these times.

  20. Live animals for preclinical medical student surgical training

    PubMed Central

    DeMasi, Stephanie C.; Katsuta, Eriko; Takabe, Kazuake

    2016-01-01

    Aims The use of live animals for surgical training is a well-known, deliberated topic. However, medical students who use live animals rate the experience high not only in improving their surgical techniques, but also positively influencing their confidence levels in the operating room later in their careers. Therefore, we hypothesized that the use of live animal models is a unique and influential component of preclinical medical education. Materials and Methods Medical student performed the following surgical procedures using mice; surgical orthotopic implantation of cancer cells into fat pad and subsequently a radical mastectomy. The improvement of skill was then analyzed. Results All cancer cell inoculations were performed successfully. Improvement of surgical skills during the radical mastectomy procedure was documented in all parameters. All wounds healed without breakdown or dehiscence. The appropriate interval between interrupted sutures was ascertained after fifth wound closure. The speed of interrupted sutures was doubled by last wound closure. The time required to complete a radical mastectomy decreased by almost half. A single animal died immediately following the operation due to inappropriate anesthesia, which was attributed to the lack of understanding of the overall operative management. Conclusion Surgical training using live animals for preclinical medical students provides a unique learning experience, not only in improving surgical skills but also and arguably most importantly, to introduce the student to the complexities of the perioperative environment in a way that most closely resembles the stress and responsibility that the operating room demands. PMID:28713875

  1. Subjective memory complaints in preclinical autosomal dominant Alzheimer disease.

    PubMed

    Norton, Daniel J; Amariglio, Rebecca; Protas, Hillary; Chen, Kewei; Aguirre-Acevedo, Daniel C; Pulsifer, Brendan; Castrillon, Gabriel; Tirado, Victoria; Munoz, Claudia; Tariot, Pierre; Langbaum, Jessica B; Reiman, Eric M; Lopera, Francisco; Sperling, Reisa A; Quiroz, Yakeel T

    2017-10-03

    To cross-sectionally study subjective memory complaints (SMC) in autosomal dominant Alzheimer disease (ADAD). We examined self-reported and study partner-based SMC in 52 young, cognitively unimpaired individuals from a Colombian kindred with early-onset ADAD. Twenty-six carried the PSEN-1 E280A mutation, averaging 7 years of age younger than the kindred's expected clinical onset. Twenty-six were age-matched noncarriers. Participants also underwent structural MRI and cognitive testing. Self-reported SMC were greater in carriers than noncarriers ( p = 0.02). Study partner-based SMC did not differ between groups ( p = 0.21), but in carriers increased with age ( r = 0.66, p < 0.001) and decreased with hippocampal volume ( r = -0.35, p = 0.08). Cognitively unimpaired PSEN-1 carriers have elevated SMC. Self-reported SMC may be a relatively early indicator of preclinical AD, while partner- reported SMC increases later in preclinical AD, closer to clinical onset. © 2017 American Academy of Neurology.

  2. Optimized design and analysis of preclinical intervention studies in vivo

    PubMed Central

    Laajala, Teemu D.; Jumppanen, Mikael; Huhtaniemi, Riikka; Fey, Vidal; Kaur, Amanpreet; Knuuttila, Matias; Aho, Eija; Oksala, Riikka; Westermarck, Jukka; Mäkelä, Sari; Poutanen, Matti; Aittokallio, Tero

    2016-01-01

    Recent reports have called into question the reproducibility, validity and translatability of the preclinical animal studies due to limitations in their experimental design and statistical analysis. To this end, we implemented a matching-based modelling approach for optimal intervention group allocation, randomization and power calculations, which takes full account of the complex animal characteristics at baseline prior to interventions. In prostate cancer xenograft studies, the method effectively normalized the confounding baseline variability, and resulted in animal allocations which were supported by RNA-seq profiling of the individual tumours. The matching information increased the statistical power to detect true treatment effects at smaller sample sizes in two castration-resistant prostate cancer models, thereby leading to saving of both animal lives and research costs. The novel modelling approach and its open-source and web-based software implementations enable the researchers to conduct adequately-powered and fully-blinded preclinical intervention studies, with the aim to accelerate the discovery of new therapeutic interventions. PMID:27480578

  3. Optimized design and analysis of preclinical intervention studies in vivo.

    PubMed

    Laajala, Teemu D; Jumppanen, Mikael; Huhtaniemi, Riikka; Fey, Vidal; Kaur, Amanpreet; Knuuttila, Matias; Aho, Eija; Oksala, Riikka; Westermarck, Jukka; Mäkelä, Sari; Poutanen, Matti; Aittokallio, Tero

    2016-08-02

    Recent reports have called into question the reproducibility, validity and translatability of the preclinical animal studies due to limitations in their experimental design and statistical analysis. To this end, we implemented a matching-based modelling approach for optimal intervention group allocation, randomization and power calculations, which takes full account of the complex animal characteristics at baseline prior to interventions. In prostate cancer xenograft studies, the method effectively normalized the confounding baseline variability, and resulted in animal allocations which were supported by RNA-seq profiling of the individual tumours. The matching information increased the statistical power to detect true treatment effects at smaller sample sizes in two castration-resistant prostate cancer models, thereby leading to saving of both animal lives and research costs. The novel modelling approach and its open-source and web-based software implementations enable the researchers to conduct adequately-powered and fully-blinded preclinical intervention studies, with the aim to accelerate the discovery of new therapeutic interventions.

  4. Implementation of compressive sensing for preclinical cine-MRI

    NASA Astrophysics Data System (ADS)

    Tan, Elliot; Yang, Ming; Ma, Lixin; Zheng, Yahong Rosa

    2014-03-01

    This paper presents a practical implementation of Compressive Sensing (CS) for a preclinical MRI machine to acquire randomly undersampled k-space data in cardiac function imaging applications. First, random undersampling masks were generated based on Gaussian, Cauchy, wrapped Cauchy and von Mises probability distribution functions by the inverse transform method. The best masks for undersampling ratios of 0.3, 0.4 and 0.5 were chosen for animal experimentation, and were programmed into a Bruker Avance III BioSpec 7.0T MRI system through method programming in ParaVision. Three undersampled mouse heart datasets were obtained using a fast low angle shot (FLASH) sequence, along with a control undersampled phantom dataset. ECG and respiratory gating was used to obtain high quality images. After CS reconstructions were applied to all acquired data, resulting images were quantitatively analyzed using the performance metrics of reconstruction error and Structural Similarity Index (SSIM). The comparative analysis indicated that CS reconstructed images from MRI machine undersampled data were indeed comparable to CS reconstructed images from retrospective undersampled data, and that CS techniques are practical in a preclinical setting. The implementation achieved 2 to 4 times acceleration for image acquisition and satisfactory quality of image reconstruction.

  5. Operation of the Preclinical Head Scanner for Proton CT.

    PubMed

    Sadrozinski, H F-W; Geoghegan, T; Harvey, E; Johnson, R P; Plautz, T E; Zatserklyaniy, A; Bashkirov, V; Hurley, R F; Piersimoni, P; Schulte, R W; Karbasi, P; Schubert, K E; Schultze, B; Giacometti, V

    2016-09-21

    We report on the operation and performance tests of a preclinical head scanner developed for proton computed tomography (pCT). After extensive preclinical testing, pCT is intended to be employed in support of proton therapy treatment planning and pre-treatment verification in patients undergoing particle-beam therapy. In order to assess the performance of the scanner, we have performed CT scans with 200 MeV protons from both the synchrotron of the Loma Linda University Medical Center (LLUMC) and the cyclotron of the Northwestern Medicine Chicago Proton Center (NMCPC). The very high sustained rate of data acquisition, exceeding one million protons per second, allowed a full 360° scan to be completed in less than 7 minutes. The reconstruction of various phantoms verified accurate reconstruction of the proton relative stopping power (RSP) and the spatial resolution in a variety of materials. The dose for an image with better than 1% uncertainty in the RSP is found to be close to 1 mGy.

  6. Melatonin and breast cancer: Evidences from preclinical and human studies.

    PubMed

    Kubatka, Peter; Zubor, Pavol; Busselberg, Dietrich; Kwon, Taeg Kyu; Adamek, Mariusz; Petrovic, Daniel; Opatrilova, Radka; Gazdikova, Katarina; Caprnda, Martin; Rodrigo, Luis; Danko, Jan; Kruzliak, Peter

    2018-02-01

    The breast cancer affects women with high mortality and morbidity worldwide. The risk is highest in the most developed world but also is markedly rising in the developing countries. It is well documented that melatonin has a significant anti-tumor activities demonstrated on various cancer types in a plethora of preclinical studies. In breast cancer, melatonin is capable to disrupt estrogen-dependent cell signaling, resulting in a reduction of estrogen-stimulated cells, moreover, it's obvious neuro-immunomodulatory effect in organism was described. Several prospective studies have demonstrated the inverse correlation between melatonin metabolites and the risk of breast cancer. This correlation was confirmed by observational studies that found lower melatonin levels in breast cancer patients. Moreover, clinical studies have showed that circadian disruption of melatonin synthesis, specifically night shift work, is linked to increased breast cancer risk. In this regard, proper light/dark exposure with more selective use of light at night along with oral supplementation of melatonin may have benefits for high-risk women. The results of current preclinical studies, the mechanism of action, and clinical efficacy of melatonin in breast cancer are reviewed in this paper. Melatonin alone or in combined administration seems to be appropriate drug for the treatment of early stages of breast cancer with documented low toxicity over a wide range of doses. These and other issues are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. A preclinical mouse model of invasive lobular breast cancer metastasis.

    PubMed

    Doornebal, Chris W; Klarenbeek, Sjoerd; Braumuller, Tanya M; Klijn, Christiaan N; Ciampricotti, Metamia; Hau, Cheei-Sing; Hollmann, Markus W; Jonkers, Jos; de Visser, Karin E

    2013-01-01

    Metastatic disease accounts for more than 90% of cancer-related deaths, but the development of effective antimetastatic agents has been hampered by the paucity of clinically relevant preclinical models of human metastatic disease. Here, we report the development of a mouse model of spontaneous breast cancer metastasis, which recapitulates key events in its formation and clinical course. Specifically, using the conditional K14cre;Cdh1(F/F);Trp53(F/F) model of de novo mammary tumor formation, we orthotopically transplanted invasive lobular carcinoma (mILC) fragments into mammary glands of wild-type syngeneic hosts. Once primary tumors were established in recipient mice, we mimicked the clinical course of treatment by conducting a mastectomy. After surgery, recipient mice succumbed to widespread overt metastatic disease in lymph nodes, lungs, and gastrointestinal tract. Genomic profiling of paired mammary tumors and distant metastases showed that our model provides a unique tool to further explore the biology of metastatic disease. Neoadjuvant and adjuvant intervention studies using standard-of-care chemotherapeutics showed the value of this model in determining therapeutic agents that can target early- and late-stage metastatic disease. In obtaining a more accurate preclinical model of metastatic lobular breast cancer, our work offers advances supporting the development of more effective treatment strategies for metastatic disease.

  8. An overview of bilastine metabolism during preclinical investigations.

    PubMed

    Lucero, María Luisa; Gonzalo, Ana; Mumford, Rory; Betanzos, Mónica; Alejandro, Ana

    2012-06-01

    Knowledge of the biotransformation of oral H₁ antihistamines is clinically important because it can define their pharmacokinetic profile through possible effects on absorption (i.e., first-pass metabolism) and elimination. Further, clinically significant interactions with inhibitors of cytochrome P450 (CYP) have previously been reported for drugs of this therapeutic group, such as terfenadine and astemizole, indicating the possibility of drug-drug interactions involving agents that share the same metabolic pathway. The aim of this article was to review the preclinical testing of a new antihistamine (i.e., bilastine) in terms of its biotransformation in various animal species, including humans, and to evaluate its potential for possible drug-drug interactions involving the CYP system. A wide array of preclinical experiments were reviewed, all of which demonstrated that bilastine undergoes minimal metabolism in all species tested to date, including humans. Further, bilastine did not interact significantly, either as an inhibitor or inducer, with the CYP enzyme system, suggesting a low propensity for involvement in drug-drug interactions. These characteristics demonstrate the potential for bilastine to be a good choice for allergic patients receiving treatment for other concomitant diseases, including those with renal or hepatic dysfunction.

  9. Functional connectivity and graph theory in preclinical Alzheimer's disease.

    PubMed

    Brier, Matthew R; Thomas, Jewell B; Fagan, Anne M; Hassenstab, Jason; Holtzman, David M; Benzinger, Tammie L; Morris, John C; Ances, Beau M

    2014-04-01

    Alzheimer's disease (AD) has a long preclinical phase in which amyloid and tau cerebral pathology accumulate without producing cognitive symptoms. Resting state functional connectivity magnetic resonance imaging has demonstrated that brain networks degrade during symptomatic AD. It is unclear to what extent these degradations exist before symptomatic onset. In this study, we investigated graph theory metrics of functional integration (path length), functional segregation (clustering coefficient), and functional distinctness (modularity) as a function of disease severity. Further, we assessed whether these graph metrics were affected in cognitively normal participants with cerebrospinal fluid evidence of preclinical AD. Clustering coefficient and modularity, but not path length, were reduced in AD. Cognitively normal participants who harbored AD biomarker pathology also showed reduced values in these graph measures, demonstrating brain changes similar to, but smaller than, symptomatic AD. Only modularity was significantly affected by age. We also demonstrate that AD has a particular effect on hub-like regions in the brain. We conclude that AD causes large-scale disconnection that is present before onset of symptoms. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Left ventricular remodeling in preclinical experimental mitral regurgitation of dogs.

    PubMed

    Dillon, A Ray; Dell'Italia, Louis J; Tillson, Michael; Killingsworth, Cheryl; Denney, Thomas; Hathcock, John; Botzman, Logan

    2012-03-01

    Dogs with experimental mitral regurgitation (MR) provide insights into the left ventricular remodeling in preclinical MR. The early preclinical left ventricular (LV) changes after mitral regurgitation represent progressive dysfunctional remodeling, in that no compensatory response returns the functional stroke volume (SV) to normal even as total SV increases. The gradual disease progression leads to mitral annulus stretch and enlargement of the regurgitant orifice, further increasing the regurgitant volume. Remodeling with loss of collagen weave and extracellular matrix (ECM) is accompanied by stretching and hypertrophy of the cross-sectional area and length of the cardiomyocyte. Isolated ventricular cardiomyocytes demonstrate dysfunction based on decreased cell shortening and reduced intracellular calcium transients before chamber enlargement or decreases in contractility in the whole heart can be clinically appreciated. The genetic response to increased end-diastolic pressure is down-regulation of genes associated with support of the collagen and ECM and up-regulation of genes associated with matrix remodeling. Experiments have not demonstrated any beneficial effects on remodeling from treatments that decrease afterload via blocking the renin-angiotensin system (RAS). Beta-1 receptor blockade and chymase inhibition have altered the progression of the LV remodeling and have supported cardiomyocyte function. The geometry of the LV during the remodeling provides insight into the importance of regional differences in responses to wall stress. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Utilization of blended learning to teach preclinical endodontics.

    PubMed

    Maresca, Cristina; Barrero, Carlos; Duggan, Dereck; Platin, Enrique; Rivera, Eric; Hannum, Wallace; Petrola, Frank

    2014-08-01

    Blended learning (BL) is the integration of classroom learning with an online environment. The purpose of this study was to determine whether dental students who experienced BL in a preclinical endodontic course demonstrated better manual skills, conceptual knowledge, and learning experience compared to those experiencing traditional learning. All eighty-one students (100 percent) in a preclinical endodontics course agreed to participate and were assigned to either the traditional or BL group. A root canal procedure was used to determine the level of manual skills gained by each group. Pre- and post-intervention quizzes were given to all students to evaluate conceptual knowledge gained, and the students' perspectives on the methods were evaluated with a survey. The BL group scored better than the traditional group on the manual skills exercise at a statistically significant level (p=0.0067). There were no differences in the post-intervention quiz scores between the two groups, and the students' opinions were positive regarding BL. With BL, the students were able to learn and demonstrate dental skills at a high level.

  12. [Preclinical prognosis of pyracetam and picamilon safety based on acute toxicity data].

    PubMed

    Bugaeva, L I; Spasov, A A; Verovskiĭ, V E; Iezhitsa, I N

    2003-01-01

    A comparative acute toxicity test of the nootropic drugs piracetam and picamilon was performed on rats. The study was based on the principles of integral evaluation of the drug effect upon the functional and behavioral state of animals. It was found that the conventional therapeutic index does not coincide with the actual therapeutic activity range. Piracetam and picamilon, while exhibiting significantly different toxicity, are characterized by approximately equal ranges of the therapeutic activity.

  13. Preclinical safety evaluation of submicronized sildenafil citrate nebulization solution in small experimental animals.

    PubMed

    Agrawal, Priyanka; Soni, Sandeep; Mittal, Gaurav; Bhatnagar, Aseem

    2015-01-01

    Sildenafil citrate (SC) nebulization solution has the potential to treat pulmonary hypertension by delivering high concentration directly to the respiratory system while minimizing systemic drug exposure and associated toxicity. The objective of the present study was to evaluate the potential toxicity of aerosolized SC (inhaled) in Sprague dawley rats for 28 days. The rats were randomly divided into five groups (n = 6). Placebo (normal saline) was inhaled to group I (control). Group II was exposed to therapeutic dose (TD): 20 mg/kg, while group 3 and group 4 were exposed to 3 TD and 6 TD, respectively, till 28 days and toxicokinetic parameters were evaluated in group V. The particle size of the nebulized solution of SC (1%) was measured by using Anderson Cascade Impactor. At the end of experiment, all animals were sacrificed. Endpoints used to evaluate potential toxicity of inhaled sildenafil citrate were clinical observations, body weight, and clinical pathology along with broncho-alveolar lavage (BAL) Fluid investigation. ACI study has shown that more than 70% aerosolized drug particles were in submicron range (0.3-0.5 μm). There was no systemic toxicity or clinically limiting local respiratory toxicity associated with inhalation exposure to SC nebulization solution at 6 TD. No significant changes were observed in the level of different blood and BALF parameters in treated groups in comparison to control. Histopathological examination revealed no abnormal findings in the animals of treated group. The data demonstrate that aerosolized sildenafil citrate is well tolerated in rats and suggest its use in humans.

  14. The state of radiologic teaching practice in preclinical medical education: survey of American medical, osteopathic, and podiatric schools.

    PubMed

    Rubin, Zachary; Blackham, Kristine

    2015-04-01

    This study describes the state of preclinical radiology curricula in North American allopathic, osteopathic, and podiatric medical schools. An online survey of teaching methods, radiology topics, and future plans was developed. The Associations of American Medical Colleges, Colleges of Osteopathic Medicine, and Colleges of Podiatric Medicine listing for all US, Canadian, and Puerto Rican schools was used for contact information for directors of anatomy and/or radiology courses. Letters were sent via e-mail to 198 schools, with a link to the anonymous survey. Of 198 schools, 98 completed the survey (48%). Radiology curricula were integrated with other topics (91%), and taught by anatomists (42%) and radiologists (43%). The majority of time was spent on the topic of anatomy correlation (35%). Time spent teaching general radiology topics in the curriculum, such as physics (3%), modality differences (6%), radiation safety (2%), and contrast use (2%) was limited. Most schools had plans to implement an innovative teaching method in the near future (62%). The major challenges included limits on: time in the curriculum (73%); resources (32%); and radiology faculty participation (30%). A total of 82% reported that their curriculum did not model the suggestions made by the Alliance of Medical Student Educators in Radiology. This survey describes the current state of preclinical radiology teaching: curricula were nonstandard, integrated into other courses, and predominantly used for anatomy correlation. Other important contextual principles of the practice of radiology were seldom taught. Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  15. Poly-(ADP-ribose)-polymerase inhibitors as radiosensitizers: a systematic review of pre-clinical and clinical human studies.

    PubMed

    Lesueur, Paul; Chevalier, François; Austry, Jean-Baptiste; Waissi, Waisse; Burckel, Hélène; Noël, Georges; Habrand, Jean-Louis; Saintigny, Yannick; Joly, Florence

    2017-09-15

    Poly-(ADP-Ribose)-Polymerase (PARP) inhibitors are becoming important actors of anti-neoplasic agents landscape, with recent but narrow FDA's approvals for ovarian BRCA mutated cancers and prostatic cancer. Nevertheless, PARP inhibitors are also promising drugs for combined treatments particularly with radiotherapy. More than seven PARP inhibitors have been currently developed. Central Role of PARP in DNA repair, makes consider PARP inhibitor as potential radiosensitizers, especially for tumors with DNA repair defects, such as BRCA mutation, because of synthetic lethality. Furthermore the replication-dependent activity of PARP inhibitor helps to maintain the differential effect between tumoral and healthy tissues. Inhibition of chromatin remodeling, G2/M arrest, vasodilatory effect induced by PARP inhibitor, also participate to their radio-sensitization effect. Here, after highlighting mechanisms of PARP inhibitors radiosensitization we methodically searched PubMed, Google Scholar, Cochrane Databases and meeting proceedings for human pre-clinical and clinical studies that evaluated PARP inhibitor radiosensitizing effect. Enhancement ratio, when available, was systematically reported. Sixty four studies finally met our selection criteria and were included in the analysis. Only three pre-clinical studies didn't find any radiosensitizing effect. Median enhancement ratio vary from 1,3 for prostate tumors to 1,5 for lung cancers. Nine phase I or II trials assessed safety data. PARP inhibitors are promising radiosensitizers, but need more clinical investigation. The next ten years will be determining for judging their real potential.

  16. Serine 302 Phosphorylation of Mouse Insulin Receptor Substrate 1 (IRS1) Is Dispensable for Normal Insulin Signaling and Feedback Regulation by Hepatic S6 Kinase*

    PubMed Central

    Copps, Kyle D.; Hançer, Nancy J.; Qiu, Wei; White, Morris F.

    2016-01-01

    Constitutive activation of the mammalian target of rapamycin complex 1 and S6 kinase (mTORC1→ S6K) attenuates insulin-stimulated Akt activity in certain tumors in part through “feedback” phosphorylation of the upstream insulin receptor substrate 1 (IRS1). However, the significance of this mechanism for regulating insulin sensitivity in normal tissue remains unclear. We investigated the function of Ser-302 in mouse IRS1, the major site of its phosphorylation by S6K in vitro, through genetic knock-in of a serine-to-alanine mutation (A302). Although insulin rapidly stimulated feedback phosphorylation of Ser-302 in mouse liver and muscle, homozygous A302 mice (A/A) and their knock-in controls (S/S) exhibited similar glucose homeostasis and muscle insulin signaling. Furthermore, both A302 and control primary hepatocytes from which Irs2 was deleted showed marked inhibition of insulin-stimulated IRS1 tyrosine phosphorylation and PI3K binding after emetine treatment to raise intracellular amino acids and activate mTORC1 → S6K signaling. To specifically activate mTORC1 in mouse tissue, we deleted hepatic Tsc1 using Cre adenovirus. Although it moderately decreased IRS1/PI3K association and Akt phosphorylation in liver, Tsc1 deletion failed to cause glucose intolerance or promote hyperinsulinemia in mixed background A/A or S/S mice. Moreover, Tsc1 deletion failed to stimulate phospho-Ser-302 or other putative S6K sites within IRS1, whereas ribosomal S6 protein was constitutively phosphorylated. Following acute Tsc1 deletion from hepatocytes, Akt phosphorylation, but not IRS1/PI3K association, was rapidly restored by treatment with the mTORC1 inhibitor rapamycin. Thus, within the hepatic compartment, mTORC1 → S6K signaling regulates Akt largely through IRS-independent means with little effect upon physiologic insulin sensitivity. PMID:26846849

  17. Effect of orthodontic force on the expression of PI3K, Akt, and P70S6 K in the human periodontal ligament during orthodontic loading.

    PubMed

    Xu, Yunhe; Shen, Jiayuan; Muhammed, Fenik Kaml; Zheng, Bowen; Zhang, Yuejiao; Liu, Yi

    2017-10-01

    The mammalian target of rapamycin (mTOR) is an atypical serine/threonine protein kinases involved in the regulation of cell growth, proliferation, and differentiation through the PI3K/Akt/mTOR/P70S6 K signalling pathway. P70S6 K as a downstream molecule of mTOR is activated by phosphorylation and subsequently promotes the synthesis of ribosomal and translational proteins. In this study, we investigated the role of PI3K, Akt, and P70S6 K in human periodontal tissue remodelling during orthodontic loading. The prepared tissue specimens taken from 4 extracted premolars were processed for immunolabelling. The changes in the expression of PI3K, Akt, and P70S6 K in the periodontal tissues were detected by real-time quantitative-polymerase chain reaction and Western blot analysis. The results from real-time quantitative-polymerase chain reaction and Western blot both showed that the expression of PI3K, Akt, and P70S6 K in the experimental group began to increase at 3 days and increased significantly at 10 days, then decreased approaching the control group level at 28 days. Our findings showed that the expression of PI3K, Akt, and P70S6 K in human periodontal ligament demonstrated a variability during the orthodontic loading, which suggested that the PI3K/Akt/mTOR/P70S6 K signal pathway was involved in orthodontic tooth movement and played a role in the process of periodontium remodelling. Copyright © 2017 John Wiley & Sons, Ltd.

  18. The mechanistic target of rapamycin (mTOR) pathway and S6 Kinase mediate diazoxide preconditioning in primary rat cortical neurons.

    PubMed

    Dutta, Somhrita; Rutkai, Ibolya; Katakam, Prasad V G; Busija, David W

    2015-09-01

    We examined the role of the mechanistic target of rapamycin (mTOR) pathway in delayed diazoxide (DZ)-induced preconditioning of cultured rat primary cortical neurons. Neurons were treated for 3 days with 500 μM DZ or feeding medium and then exposed to 3 h of continuous normoxia in Dulbecco's modified eagle medium with glucose or with 3 h of oxygen-glucose deprivation (OGD) followed by normoxia and feeding medium. The OGD decreased viability by 50%, depolarized mitochondria, and reduced mitochondrial respiration, whereas DZ treatment improved viability and mitochondrial respiration, and suppressed reactive oxygen species production, but did not restore mitochondrial membrane potential after OGD. Neuroprotection by DZ was associated with increased phosphorylation of protein kinase B (Akt), mTOR, and the major mTOR downstream substrate, S6 Kinase (S6K). The mTOR inhibitors rapamycin and Torin-1, as well as S6K-targeted siRNA abolished the protective effects of DZ. The effects of DZ on mitochondrial membrane potential and reactive oxygen species production were not affected by rapamycin. Preconditioning with DZ also changed mitochondrial and non-mitochondrial oxygen consumption rates. We conclude that in addition to reducing reactive oxygen species (ROS) production and mitochondrial membrane depolarization, DZ protects against OGD by activation of the Akt-mTOR-S6K pathway and by changes in mitochondrial respiration. Ischemic strokes have limited therapeutic options. Diazoxide (DZ) preconditioning can reduce neuronal damage. Using oxygen-glucose deprivation (OGD), we studied Akt/mTOR/S6K signaling and mitochondrial respiration in neuronal preconditioning. We found DZ protects neurons against OGD via the Akt/mTOR/S6K pathway and alters the mitochondrial and non-mitochondrial oxygen consumption rate. This suggests that the Akt/mTOR/S6k pathway and mitochondria are novel stroke targets. © 2015 International Society for Neurochemistry.

  19. The Akt/mTOR/p70S6K pathway is activated in IgA nephropathy and rapamycin may represent a viable treatment option.

    PubMed

    Tian, Jihua; Wang, Yanhong; Guo, Haixiu; Li, Rongshan

    2015-12-01

    IgA nephropathy (IgAN) is one of the most frequent forms of glomerulonephritis, and 20 to 40% of patients progress to end-stage renal disease (ESRD) within 20 years of disease onset. However, little is known about the molecular pathways involved in the altered physiology of mesangial cells during IgAN progression. This study was designed to explore the role of mTOR signaling and the potential of targeted rapamycin therapy in a rat model of IgAN. After establishing an IgA nephropathy model, the rats were randomly divided into four groups: control, control+rapamycin, IgAN and IgA+rapamycin. Western blotting and immunohistochemistry were performed to determine phospho-Akt, p70S6K and S6 protein levels. Coomassie Brilliant Blue was utilized to measure 24-h urinary protein levels. The biochemical parameters of the rats were analyzed with an autoanalyzer. To evaluate IgA deposition in the glomeruli, FITC-conjugated goat anti-rat IgA antibody was used for direct immunofluorescence. Cellular proliferation and the mesangial matrix in glomeruli were assayed via histological and morphometric procedures. Our results showed that p70S6K, S6 and Akt phosphorylation were significantly upregulated in IgAN rats, and rapamycin effectively inhibited p70S6K and S6 phosphorylation. A low dose of the mTOR inhibitor rapamycin reduced proteinuria, inhibited IgA deposition, and protected kidney function in an IgAN rat model. Low-dose rapamycin treatment corresponded to significantly lower cellular proliferation rates and a decreased mesangial matrix in the glomeruli. In conclusion, the Akt/mTOR/p70S6K pathway was activated in IgAN, and our findings suggested that rapamycin may represent a viable option for the treatment of IgAN. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Attenuation of Proinflammatory Responses by S-[6]-Gingerol via Inhibition of ROS/NF-Kappa B/COX2 Activation in HuH7 Cells.

    PubMed

    Li, Xiao-Hong; McGrath, Kristine C Y; Tran, Van H; Li, Yi-Ming; Duke, Colin C; Roufogalis, Basil D; Heather, Alison K

    2013-01-01

    Introduction. Hepatic inflammation underlies the pathogenesis of chronic diseases such as insulin resistance and type 2 diabetes mellitus. S-[6]-Gingerol has been shown to have anti-inflammatory properties. Important inflammatory mediators of interleukins include nuclear factor κ B (NF κ B) and cyclooxygenase 2 (COX2). We now explore the mechanism of anti-inflammatory effects of S-[6]-gingerol in liver cells. Methods. HuH7 cells were stimulated with IL1β to establish an in vitro hepatic inflammatory model. Results. S-[6]-Gingerol attenuated IL1β-induced inflammation and oxidative stress in HuH7 cells, as evidenced by decreasing mRNA levels of inflammatory factor IL6, IL8, and SAA1, suppression of ROS generation, and increasing mRNA levels of DHCR24. In addition, S-[6]-gingerol reduced IL1β-induced COX2 upregulation as well as NF κ B activity. Similar to the protective effects of S-[6]-gingerol, both NS-398 (a selective COX2 inhibitor) and PDTC (a selective NF κ B inhibitor) suppressed mRNA levels of IL6, IL8, and SAA1. Importantly, PDTC attenuated IL1β-induced overexpression of COX2. Of particular note, the protective effect of S-[6]-gingerol against the IL1β-induced inflammatory response was similar to that of BHT, an ROS scavenger. Conclusions. The findings of this study demonstrate that S-[6]-gingerol protects HuH7 cells against IL1β-induced inflammatory insults through inhibition of the ROS/NF κ B/COX2 pathway.

  1. Preliminary study for small animal preclinical hadrontherapy facility

    NASA Astrophysics Data System (ADS)

    Russo, G.; Pisciotta, P.; Cirrone, G. A. P.; Romano, F.; Cammarata, F.; Marchese, V.; Forte, G. I.; Lamia, D.; Minafra, L.; Bravatá, V.; Acquaviva, R.; Gilardi, M. C.; Cuttone, G.

    2017-02-01

    Aim of this work is the study of the preliminary steps to perform a particle treatment of cancer cells inoculated in small animals and to realize a preclinical hadrontherapy facility. A well-defined dosimetric protocol was developed to explicate the steps needed in order to perform a precise proton irradiation in small animals and achieve a highly conformal dose into the target. A precise homemade positioning and holding system for small animals was designed and developed at INFN-LNS in Catania (Italy), where an accurate Monte Carlo simulation was developed, using Geant4 code to simulate the treatment in order to choose the best animal position and perform accurately all the necessary dosimetric evaluations. The Geant4 application can also be used to realize dosimetric studies and its peculiarity consists in the possibility to introduce the real target composition in the simulation using the DICOM micro-CT image. This application was fully validated comparing the results with the experimental measurements. The latter ones were performed at the CATANA (Centro di AdroTerapia e Applicazioni Nucleari Avanzate) facility at INFN-LNS by irradiating both PMMA and water solid phantom. Dosimetric measurements were performed using previously calibrated EBT3 Gafchromic films as a detector and the results were compared with the Geant4 simulation ones. In particular, two different types of dosimetric studies were performed: the first one involved irradiation of a phantom made up of water solid slabs where a layer of EBT3 was alternated with two different slabs in a sandwich configuration, in order to validate the dosimetric distribution. The second one involved irradiation of a PMMA phantom made up of a half hemisphere and some PMMA slabs in order to simulate a subcutaneous tumour configuration, normally used in preclinical studies. In order to evaluate the accordance between experimental and simulation results, two different statistical tests were made: Kolmogorov test and

  2. Levetiracetam: the preclinical profile of a new class of antiepileptic drugs?

    PubMed

    Klitgaard, H

    2001-01-01

    Levetiracetam is a new antiepileptic drug (AED) devoid of anticonvulsant activity in the two classic screening models for AEDs, the maximal electroshock and pentylenetetrazol seizure tests in both mice and rats. This contrasts a potent seizure suppression in genetic and kindled mice and rats and against chemoconvulsants inducing partial seizures in rats. The highly selective action in "epileptic" animals distinguishes levetiracetam from classic and other new AEDs that have nearly equipotent effects in normal and "epileptic" animals. Levetiracetam induces minor behavioral alterations in normal and in kindled mice and rats. This results in an unusually high safety margin in animal models reflecting both partial and primary generalized epilepsy. Furthermore, experiments in the kindling model suggest that levetiracetam may possess antiepileptogenic properties due to a potent ability to prevent the development of kindling in mice and rats at doses devoid of adverse effects. Electrophysiologic recordings from different experimental models suggest that levetiracetam exerts a selective action against abnormal patterns of neuronal activity, which probably explains its selective protection in epileptic animals and its unique tolerability. This effect appears to derive from one or more novel mechanisms of action that do not involve a conventional interaction with traditional drug targets implicated in the modulation of inhibitory and excitatory neurotransmission. Instead, ligand-binding assays have disclosed a brain-specific binding site for levetiracetam. These studies reveal a unique preclinical profile of levetiracetam, distinct from that of all known AEDs, suggesting that levetiracetam could represent the first agent in a new class of AEDs.

  3. Post hoc assessment of the immunogenicity of bioengineered factor VIIa demonstrates the use of preclinical tools.

    PubMed

    Lamberth, Kasper; Reedtz-Runge, Stine Louise; Simon, Jonathan; Klementyeva, Ksenia; Pandey, Gouri Shankar; Padkjær, Søren Berg; Pascal, Véronique; León, Ileana R; Gudme, Charlotte Nini; Buus, Søren; Sauna, Zuben E

    2017-01-11

    Immunogenicity is an important consideration in the licensure of a therapeutic protein because the development of neutralizing anti-drug antibodies (ADAs) can affect both safety and efficacy. Neoantigens introduced by bioengineering of a protein drug are a particular cause for concern. The development of a bioengineered recombinant factor VIIa (rFVIIa) analog was discontinued after phase 3 trials because of the development of ADAs. The unmodified parent molecule (rFVIIa), on the other hand, has been successfully used as a drug for more than two decades with no reports of immunogenicity in congenital hemophilia patients with inhibitors. We used computational and experimental methods to demonstrate that the observed ADAs could have been elicited by neoepitopes in the engineered protein. The human leukocyte antigen type of the patients who developed ADAs is consistent with this hypothesis of a neoepitope-driven immune response, a finding that might have implications for the preclinical screening of therapeutic protein analogs. Copyright © 2017, American Association for the Advancement of Science.

  4. Discovery and preclinical development of dasabuvir for the treatment of hepatitis C infection.

    PubMed

    El Kassas, Mohamed; Elbaz, Tamer; Hafez, Enas; Wifi, Mohamed Naguib; Esmat, Gamal

    2017-06-01

    Hepatitis C virus (HCV) is a leading cause of liver-related morbidity and mortality. Positively, the introduction of new directly-acting antivirals (DAAs) have led to dramatic improvements in response rates to antiviral therapy. Furthermore, newer generations of DAAs have demonstrated better safety profiles as well as efficacy than older generations. Current treatment recommendations are based on different combinations of DAAs. Current combination therapies rely on agents that target the different steps of viral replication by using different molecules from various DAAs families. Areas covered: In this review, the authors summarize data from of one of the recently developed NS5B polymerase inhibitors, dasabuvir, formerly known as ABT-333. Herein, the authors discuss the drug discovery data for dasabuvir including data from preclinical, toxicological resistance studies. The authors also review dasabuvir's clinical efficacy across various clinical challenges, in addition to its limitations in clinical practice. Expert opinion: Dasabuvir represents an important medical advance when used as a combination therapy for HCV. Unfortunately, it does present limitations like low genotypic coverage and further research is still required to address some of the lingering issues.

  5. Preclinical discovery and development of maraviroc for the treatment of HIV.

    PubMed

    Veljkovic, Nevena; Vucicevic, Jelica; Tassini, Sabrina; Glisic, Sanja; Veljkovic, Veljko; Radi, Marco

    2015-06-01

    Maraviroc is a first-in-class antiretroviral (ARV) drug acting on a host cell target (CCR5), which blocks the entry of the HIV virus into the cell. Maraviroc is currently indicated for combination ARV treatment in adults infected only with CCR5-tropic HIV-1. This drug discovery case history focuses on the key studies that led to the discovery and approval of maraviroc, as well as on post-launch clinical reports. The article is based on the data reported in published preclinical and clinical studies, conference posters and on drug package data. The profound understanding of HIV's entry mechanisms has provided a strong biological rationale for targeting the chemokine receptor CCR5. The CCR5-antagonist mariviroc, with its unique mode of action and excellent safety profile, is an important therapeutic option for HIV patients. In general, the authors believe that targeting host factors is a useful approach for combating new and re-emerging transmissible diseases, as well as pathogens that easily become resistant to common antiviral drugs. Maraviroc, offering a potent and safe cellular receptor-mediated pharmacological response to HIV, has paved the way for the development of a new generation of host-targeting antivirals.

  6. Gas formation and biological effects of biodegradable magnesium in a preclinical and clinical observation

    PubMed Central

    Lee, Kwang-Bok; Bode, Ken; Kwon, Tae-Young; Jeon, Moo Heon

    2018-01-01

    Abstract Magnesium alloys are biodegradable metals receiving increasing attention, but the clinical applications of these materials are delayed by concerns over the rapid corrosion rate and gas formation. Unlike corrosion, which weakens mechanical properties, the gas formation issue has received little attention. Therefore, we evaluated the gas formation and biological effects for Mg implants through preclinical (immersed in Earle’s balanced salt solution and in vivo) and clinical studies. The immersion test examined the gas volume and composition. The in vivo study also examined gas volume and histological analysis. The clinical study examined the gas volume and safety after Mg screw metatarsal fixation. Gas was mainly composed of H2, CO and CO2. Maximum volumes of gas formed after 5 days for in vivo and 7 days in clinical study. Within the clinical examination, two superficial wound complications healed with local wound care. Osteolytic lesions in the surrounding metaphysis of the Mg screw insertion developed in all cases and union occurred at 3 months. Mg implants released gas with variable volumes and composition (H2, CO, and CO2), with no long-term toxic effects on the surrounding tissue. The implants enabled bone healing, although complications of wound breakdown and osteolytic lesions developed. PMID:29707071

  7. Preclinical evaluation of WYE-687, a mTOR kinase inhibitor, as a potential anti-acute myeloid leukemia agent

    SciTech Connect

    Cheng, Feng; Wang, Lingling; Shen, Yunfeng

    Mammalian target of rapamycin (mTOR) as a potential drug target for treatment of acute myeloid leukemia (AML). Here, we investigated the potential anti-leukemic activity by WYE-687, a potent mTOR kinase inhibitor. We demonstrated that WYE-687 potently inhibited survival and proliferation of established (HL-60, U937, AML-193 and THP-1 lines) and human AML progenitor cells. Yet, same WYE-687 treatment was non-cytotoxic to the primary peripheral blood mononuclear leukocytes (PBMCs) isolated from healthy donors. WYE-687 induced caspase-dependent apoptotic death in above AML cells/progenitor cells. On the other hand, the pan-caspase inhibitor (Z-VAD-FMK), the caspase-3 specific inhibitor (Z-DEVD-FMK) or the caspase-9 specific inhibitor (z-LEHD-fmk)more » attenuated WYE-687-induced cytotoxicity. At the molecular level, WYE-687 concurrently inhibited activation of mTORC1 (p70S6K1 and S6 phosphorylations) and mTORC2 (AKT Ser-473 and FoxO1/3a phosphorylations), whiling downregulating mTORC1/2-regulated genes (Bcl-xL and hypoxia-inducible factor 1/2α) in both HL-60/U937 cells and human AML progenitor cells. In vivo, oral administration of WYE-687 potently inhibited U937 leukemic xenograft tumor growth in severe combined immunodeficient (SCID) mice, without causing significant toxicities. In summary, our results demonstrate that targeting mTORC1/2 by WYE-687 leads to potent antitumor activity in preclinical models of AML. - Highlights: • WYE-687 inhibits survival and proliferation of human AML cells/progenitor cells. • WYE-687 induces apoptotic death of human AML cells/progenitor cells. • WYE-687 inhibits mTORC1/2 activation in human AML cells/progenitor cells. • WYE-687 inhibits U937 xenograft growth in SCID mice.« less

  8. Medical Students' Participation in and Perception of Unprofessional Behaviors: Comparison of Preclinical and Clinical Phases

    ERIC Educational Resources Information Center

    Kulac, Esin; Sezik, Mekin; Asci, Halil; Doguc, Duygu K.

    2013-01-01

    We aimed to compare reported observations, participation in, and perceptions of unprofessional behaviors across preclinical and clinical medical students using a 23-item questionnaire that asked participants whether they witnessed or participated in the behavior and considered it unprofessional. Overall, 111 preclinical ("year 3") and…

  9. A De Novo Tool to Measure the Preclinical Learning Climate of Medical Faculties in Turkey

    ERIC Educational Resources Information Center

    Yilmaz, Nilufer Demiral; Velipasaoglu, Serpil; Sahin, Hatice; Basusta, Bilge Uzun; Midik, Ozlem; Coskun, Ozlem; Budakoglu, Isil Irem; Mamakli, Sumer; Tengiz, Funda Ifakat; Durak, Halil Ibrahim; Ozan, Sema

    2015-01-01

    Although several scales are used to measure general and clinical learning climates, there are no scales that assess the preclinical learning climate. Therefore, the purpose of this study was to develop an effective measurement tool in order to assess the preclinical learning climate. In this cross-sectional study, data were collected from 3,540…

  10. Peer-Assisted Learning: Filling the Gaps in Basic Science Education for Preclinical Medical Students

    ERIC Educational Resources Information Center

    Sammaraiee, Yezen; Mistry, Ravi D.; Lim, Julian; Wittner, Liora; Deepak, Shantal; Lim, Gareth

    2016-01-01

    In contrast to peer-assisted learning (PAL) in clinical training, there is scant literature on the efficacy of PAL during basic medical sciences teaching for preclinical students. A group of senior medical students aimed to design and deliver clinically oriented small-group tutorials after every module in the preclinical curriculum at a United…

  11. S6K2-mediated regulation of TRBP as a determinant of miRNA expression in human primary lymphatic endothelial cells

    PubMed Central

    Warner, Matthew J.; Bridge, Katherine S.; Hewitson, James P.; Hodgkinson, Michael R.; Heyam, Alex; Massa, Bailey C.; Haslam, Jessica C.; Chatzifrangkeskou, Maria; Evans, Gareth J.O.; Plevin, Michael J.; Sharp, Tyson V.; Lagos, Dimitris

    2016-01-01

    MicroRNAs (miRNAs) are short non-coding RNAs that silence mRNAs. They are generated following transcription and cleavage by the DROSHA/DGCR8 and DICER/TRBP/PACT complexes. Although it is known that components of the miRNA biogenesis machinery can be phosphorylated, it remains poorly understood how these events become engaged during physiological cellular activation. We demonstrate that S6 kinases can phosphorylate the extended C-terminal domain of TRBP and interact with TRBP in situ in primary cells. TRBP serines 283/286 are essential for S6K-mediated TRBP phosphorylation, optimal expression of TRBP, and the S6K-TRBP interaction in human primary cells. We demonstrate the functional relevance of this interaction in primary human dermal lymphatic endothelial cells (HDLECs). Angiopoietin-1 (ANG1) can augment miRNA biogenesis in HDLECs through enhancing TRBP phosphorylation and expression in an S6K2-dependent manner. We propose that the S6K2/TRBP node controls miRNA biogenesis in HDLECs and provides a molecular link between the mTOR pathway and the miRNA biogenesis machinery. PMID:27407113

  12. Age- and Diet-Specific Effects of Variation at S6 Kinase on Life History, Metabolic, and Immune Response Traits in Drosophila melanogaster

    PubMed Central

    Cho, Irene; Horn, Lucas; Felix, Tashauna M.; Foster, Leanne; Gregory, Gwendolyn; Starz-Gaiano, Michelle; Chambers, Michelle M.

    2010-01-01

    Life history theory hypothesizes that genetically based variation in life history traits results from alleles that alter age-specific patterns of energy allocation among the competing demands of reproduction, storage, and maintenance. Despite the important role that alleles with age-specific effects must play in life history evolution, few naturally occurring alleles with age-specific effects on life history traits have been identified. A recent mapping study identified S6 kinase (S6k) as a candidate gene affecting lipid storage in Drosophila. S6k is in the target of rapamycin pathway, which regulates cell growth in response to nutrient availability and has also been implicated to influence many life history traits from fecundity to life span. In this article, we used quantitative complementation tests to examine the effect of allelic variation at S6k on a range of phenotypes associated with metabolism and fitness in an age-, diet-, and sex-specific manner. We found that alleles of S6k have pleiotropic effects on total protein levels, glycogen storage, life span, and the immune response and demonstrate that these allelic effects are age, diet, and sex specific. As many of the genes in the target of rapamycin pathway are evolutionarily conserved, our data suggest that genes in this pathway could play a pivotal role in life history evolution in a wide range of taxa. PMID:20491566

  13. Minnelide reduces tumor burden in preclinical models of osteosarcoma.

    PubMed

    Banerjee, Sulagna; Thayanithy, Venugopal; Sangwan, Veena; Mackenzie, Tiffany N; Saluja, Ashok K; Subramanian, Subbaya

    2013-07-28

    Osteosarcoma is the most common bone cancer in children and adolescents with a 5-year survival rate of about 70%. In this study, we have evaluated the preclinical therapeutic efficacy of the novel synthetic drug, Minnelide, a prodrug of triptolide on osteosarcoma. Triptolide was effective in significantly inducing apoptosis in all osteosarcoma cell lines tested but had no significant effect on the human osteoblast cells. Notably, Minnelide treatment significantly reduced tumor burden and lung metastasis in the orthotopic and lung colonization models. Triptolide/Minnelide effectively downregulated the levels of pro-survival proteins such as heat shock proteins, cMYC, survivin and targets the NF-κB pathway. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Preclinical tests of an android based dietary logging application.

    PubMed

    Kósa, István; Vassányi, István; Pintér, Balázs; Nemes, Márta; Kámánné, Krisztina; Kohut, László

    2014-01-01

    The paper describes the first, preclinical evaluation of a dietary logging application developed at the University of Pannonia, Hungary. The mobile user interface is briefly introduced. The three evaluation phases examined the completeness and contents of the dietary database and the time expenditure of the mobile based diet logging procedure. The results show that although there are substantial individual differences between various dietary databases, the expectable difference with respect to nutrient contents is below 10% on typical institutional menu list. Another important finding is that the time needed to record the meals can be reduced to about 3 minutes daily especially if the user uses set-based search. a well designed user interface on a mobile device is a viable and reliable way for a personalized lifestyle support service.

  15. Pediatric Blood Pressure and Adult Preclinical Markers of Cardiovascular Disease

    PubMed Central

    Magnussen, Costan G.; Smith, Kylie J.

    2016-01-01

    A high blood pressure level in adults is considered the single most important modifiable risk factor for global disease burden, especially those of cardiovascular (CV) origin such as stroke and ischemic heart disease. Because blood pressure levels have been shown to persist from childhood to adulthood, elevations in pediatric levels have been hypothesized to lead to increased CV burden in adulthood and, as such, might provide a window in the life course where primordial and primary prevention could be focused. In the absence of substantive data directly linking childhood blood pressure levels to overt adult CV disease, this review outlines the available literature that examines the association between pediatric blood pressure and adult preclinical markers of CV disease. PMID:27168729

  16. Pre-clinical MR elastography: Principles, techniques, and applications

    NASA Astrophysics Data System (ADS)

    Bayly, P. V.; Garbow, J. R.

    2018-06-01

    Magnetic resonance elastography (MRE) is a method for measuring the mechanical properties of soft tissue in vivo, non-invasively, by imaging propagating shear waves in the tissue. The speed and attenuation of waves depends on the elastic and dissipative properties of the underlying material. Tissue mechanical properties are essential for biomechanical models and simulations, and may serve as markers of disease, injury, development, or recovery. MRE is already established as a clinical technique for detecting and characterizing liver disease. The potential of MRE for diagnosing or characterizing disease in other organs, including brain, breast, and heart is an active research area. Studies involving MRE in the pre-clinical setting, in phantoms and artificial biomaterials, in the mouse, and in other mammals, are critical to the development of MRE as a robust, reliable, and useful modality.

  17. Magnetic particle imaging: from proof of principle to preclinical applications

    NASA Astrophysics Data System (ADS)

    Knopp, T.; Gdaniec, N.; Möddel, M.

    2017-07-01

    Tomographic imaging has become a mandatory tool for the diagnosis of a majority of diseases in clinical routine. Since each method has its pros and cons, a variety of them is regularly used in clinics to satisfy all application needs. Magnetic particle imaging (MPI) is a relatively new tomographic imaging technique that images magnetic nanoparticles with a high spatiotemporal resolution in a quantitative way, and in turn is highly suited for vascular and targeted imaging. MPI was introduced in 2005 and now enters the preclinical research phase, where medical researchers get access to this new technology and exploit its potential under physiological conditions. Within this paper, we review the development of MPI since its introduction in 2005. Besides an in-depth description of the basic principles, we provide detailed discussions on imaging sequences, reconstruction algorithms, scanner instrumentation and potential medical applications.

  18. Irreproducibility in Preclinical Biomedical Research: Perceptions, Uncertainties, and Knowledge Gaps.

    PubMed

    Jarvis, Michael F; Williams, Michael

    2016-04-01

    Concerns regarding the reliability of biomedical research outcomes were precipitated by two independent reports from the pharmaceutical industry that documented a lack of reproducibility in preclinical research in the areas of oncology, endocrinology, and hematology. Given their potential impact on public health, these concerns have been extensively covered in the media. Assessing the magnitude and scope of irreproducibility is limited by the anecdotal nature of the initial reports and a lack of quantitative data on specific failures to reproduce published research. Nevertheless, remediation activities have focused on needed enhancements in transparency and consistency in the reporting of experimental methodologies and results. While such initiatives can effectively bridge knowledge gaps and facilitate best practices across established and emerging research disciplines and therapeutic areas, concerns remain on how these improve on the historical process of independent replication in validating research findings and their potential to inhibit scientific innovation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. ASTM F1717 standard for the preclinical evaluation of posterior spinal fixators: can we improve it?

    PubMed

    La Barbera, Luigi; Galbusera, Fabio; Villa, Tomaso; Costa, Francesco; Wilke, Hans-Joachim

    2014-10-01

    Preclinical evaluation of spinal implants is a necessary step to ensure their reliability and safety before implantation. The American Society for Testing and Materials reapproved F1717 standard for the assessment of mechanical properties of posterior spinal fixators, which simulates a vertebrectomy model and recommends mimicking vertebral bodies using polyethylene blocks. This set-up should represent the clinical use, but available data in the literature are few. Anatomical parameters depending on the spinal level were compared to published data or measurements on biplanar stereoradiography on 13 patients. Other mechanical variables, describing implant design were considered, and all parameters were investigated using a numerical parametric finite element model. Stress values were calculated by considering either the combination of the average values for each parameter or their worst-case combination depending on the spinal level. The standard set-up represents quite well the anatomy of an instrumented average thoracolumbar segment. The stress on the pedicular screw is significantly influenced by the lever arm of the applied load, the unsupported screw length, the position of the centre of rotation of the functional spine unit and the pedicular inclination with respect to the sagittal plane. The worst-case combination of parameters demonstrates that devices implanted below T5 could potentially undergo higher stresses than those described in the standard suggestions (maximum increase of 22.2% at L1). We propose to revise F1717 in order to describe the anatomical worst case condition we found at L1 level: this will guarantee higher safety of the implant for a wider population of patients. © IMechE 2014.

  20. Functional network integrity presages cognitive decline in preclinical Alzheimer disease.

    PubMed

    Buckley, Rachel F; Schultz, Aaron P; Hedden, Trey; Papp, Kathryn V; Hanseeuw, Bernard J; Marshall, Gad; Sepulcre, Jorge; Smith, Emily E; Rentz, Dorene M; Johnson, Keith A; Sperling, Reisa A; Chhatwal, Jasmeer P

    2017-07-04

    To examine the utility of resting-state functional connectivity MRI (rs-fcMRI) measurements of network integrity as a predictor of future cognitive decline in preclinical Alzheimer disease (AD). A total of 237 clinically normal older adults (aged 63-90 years, Clinical Dementia Rating 0) underwent baseline β-amyloid (Aβ) imaging with Pittsburgh compound B PET and structural and rs-fcMRI. We identified 7 networks for analysis, including 4 cognitive networks (default, salience, dorsal attention, and frontoparietal control) and 3 noncognitive networks (primary visual, extrastriate visual, motor). Using linear and curvilinear mixed models, we used baseline connectivity in these networks to predict longitudinal changes in preclinical Alzheimer cognitive composite (PACC) performance, both alone and interacting with Aβ burden. Median neuropsychological follow-up was 3 years. Baseline connectivity in the default, salience, and control networks predicted longitudinal PACC decline, unlike connectivity in the dorsal attention and all noncognitive networks. Default, salience, and control network connectivity was also synergistic with Aβ burden in predicting decline, with combined higher Aβ and lower connectivity predicting the steepest curvilinear decline in PACC performance. In clinically normal older adults, lower functional connectivity predicted more rapid decline in PACC scores over time, particularly when coupled with increased Aβ burden. Among examined networks, default, salience, and control networks were the strongest predictors of rate of change in PACC scores, with the inflection point of greatest decline beyond the fourth year of follow-up. These results suggest that rs-fcMRI may be a useful predictor of early, AD-related cognitive decline in clinical research settings. © 2017 American Academy of Neurology.

  1. Preclinical development of a humanized neutralizing antibody targeting HGF.

    PubMed

    Kim, Hyori; Hong, Sung Hee; Kim, Jung Yong; Kim, In-Chull; Park, Young-Whan; Lee, Song-Jae; Song, Seong-Won; Kim, Jung Ju; Park, Gunwoo; Kim, Tae Min; Kim, Yun-Hee; Park, Jong Bae; Chung, Junho; Kim, In-Hoo

    2017-03-24

    Hepatocyte growth factor (HGF) and its receptor, cMET, play critical roles in cell proliferation, angiogenesis and invasion in a wide variety of cancers. We therefore examined the anti-tumor activity of the humanized monoclonal anti-HGF antibody, YYB-101, in nude mice bearing human glioblastoma xenografts as a single agent or in combination with temozolomide. HGF neutralization, The extracellular signal-related kinases 1 and 2 (ERK1/2) phosphorylation, and HGF-induced scattering were assessed in HGF-expressing cell lines treated with YYB-101. To support clinical development, we also evaluated the preclinical pharmacokinetics and toxicokinetics in cynomolgus monkeys, and human and cynomolgus monkey tissue was stained with YYB-101 to test tissue cross-reactivity. We found that YYB-101 inhibited cMET activation in vitro and suppressed tumor growth in the orthotopic mouse model of human glioblastoma. Combination treatment with YYB-101 and temozolomide decreased tumor growth and increased overall survival compared with the effects of either agent alone. Five cancer-related genes (TMEM119, FST, RSPO3, ROS1 and NBL1) were overexpressed in YYB-101-treated mice that showed tumor regrowth. In the tissue cross-reactivity assay, critical cross-reactivity was not observed. The terminal elimination half-life was 21.7 days. Taken together, the in vitro and in vivo data demonstrated the anti-tumor efficacy of YYB-101, which appeared to be mediated by blocking the HGF/cMET interaction. The preclinical pharmacokinetics, toxicokinetics and tissue cross-reactivity data support the clinical development of YYB-101 for advanced cancer.

  2. Cued memory decline in biomarker-defined preclinical Alzheimer disease.

    PubMed

    Papp, Kathryn V; Rentz, Dorene M; Mormino, Elizabeth C; Schultz, Aaron P; Amariglio, Rebecca E; Quiroz, Yakeel; Johnson, Keith A; Sperling, Reisa A

    2017-04-11

    To determine whether a decline in cued recall is observable in the preclinical stage of Alzheimer disease (AD) in clinically normal older adults with elevated β-amyloid (Aβ) burden on PET imaging. Clinically normal older adults underwent baseline neuroimaging (PET to assess Aβ +/- status and MRI) and annual neuropsychological testing. Cox proportional hazards models were used to assess the relative risk of cued memory decline (drop of 1, 2, 3, or 4 points on the total score of the Free and Cued Selective Reminding Test) in relation to neuroimaging measures, functional status, age, sex, and education. A total of 276 older adults (Clinical Dementia Rating = 0, mean Mini-Mental State Examination score = 29 ± 1.06) were followed up for a mean of 3.6 ± 1.2 years. Despite the infrequency of cued memory decline (only 19% of participants scored ≤46/48 in total recall by year 3), Aβ + participants were 3.55 times (95% confidence interval = 1.77-7.12) more likely to exhibit decline in total recall (≤46/48) compared with their Aβ - peers. Furthermore, Aβ + participants who scored ≤46/48 had smaller hippocampal volumes ( t = 3.37, p = 0.001) and evidence of early functional decline, i.e., greater risk of progression to global Clinical Dementia Rating of 0.5 (χ 2 = 14.30, p < 0.001), compared with their Aβ + peers with intact total recall. Cued memory decline in healthy older adults may be particularly indicative of Aβ-related decline during the preclinical stage of AD and useful for identifying Aβ + clinically normal individuals at greatest risk of short-term clinical progression. © 2017 American Academy of Neurology.

  3. Cued memory decline in biomarker-defined preclinical Alzheimer disease

    PubMed Central

    Rentz, Dorene M.; Mormino, Elizabeth C.; Schultz, Aaron P.; Amariglio, Rebecca E.; Quiroz, Yakeel; Johnson, Keith A.; Sperling, Reisa A.

    2017-01-01

    Objective: To determine whether a decline in cued recall is observable in the preclinical stage of Alzheimer disease (AD) in clinically normal older adults with elevated β-amyloid (Aβ) burden on PET imaging. Methods: Clinically normal older adults underwent baseline neuroimaging (PET to assess Aβ+/− status and MRI) and annual neuropsychological testing. Cox proportional hazards models were used to assess the relative risk of cued memory decline (drop of 1, 2, 3, or 4 points on the total score of the Free and Cued Selective Reminding Test) in relation to neuroimaging measures, functional status, age, sex, and education. Results: A total of 276 older adults (Clinical Dementia Rating = 0, mean Mini-Mental State Examination score = 29 ± 1.06) were followed up for a mean of 3.6 ± 1.2 years. Despite the infrequency of cued memory decline (only 19% of participants scored ≤46/48 in total recall by year 3), Aβ+ participants were 3.55 times (95% confidence interval = 1.77–7.12) more likely to exhibit decline in total recall (≤46/48) compared with their Aβ− peers. Furthermore, Aβ+ participants who scored ≤46/48 had smaller hippocampal volumes (t = 3.37, p = 0.001) and evidence of early functional decline, i.e., greater risk of progression to global Clinical Dementia Rating of 0.5 (χ2 = 14.30, p < 0.001), compared with their Aβ+ peers with intact total recall. Conclusions: Cued memory decline in healthy older adults may be particularly indicative of Aβ-related decline during the preclinical stage of AD and useful for identifying Aβ+ clinically normal individuals at greatest risk of short-term clinical progression. PMID:28283594

  4. 1H MRS spectroscopy in preclinical autosomal dominant Alzheimer disease.

    PubMed

    Joe, Elizabeth; Medina, Luis D; Ringman, John M; O'Neill, Joseph

    2018-06-16

    1 H magnetic resonance spectroscopy (MRS) can reveal changes in brain biochemistry in vivo in humans and has been applied to late onset Alzheimer disease (AD). Carriers of mutations for autosomal dominant Alzheimer disease (ADAD) may show changes in levels of metabolites prior to the onset of clinical symptoms. Proton MR spectra were acquired at 1.5 T for 16 cognitively asymptomatic or mildly symptomatic mutation carriers (CDR < 1) and 11 non-carriers as part of a comprehensive cross-sectional study of preclinical ADAD. Levels of N-acetyl-aspartate+N-acetyl-aspartyl-glutamate (NAA), glutamate/glutamine (Glx), creatine/phosphocreate (Cr), choline (Cho), and myo-inositol (mI) in the left and right anterior cingulate and midline posterior cingulate and precuneus were compared between mutation carriers (MCs) and non-carriers (NCs) using multivariate analysis of variance with age as a covariate. Among MCs, correlations between metabolite levels and time until expected age of dementia diagnosis were calculated. MCs had significantly lower levels of NAA and Glx in the left pregenual anterior cingulate cortex, and lower levels of NAA and higher levels of mI and Cho in the precuneus compared to NCs. Increased levels of mI were seen in these regions in association with increased proximity to expected age of dementia onset. MRS shows effects of ADAD similar to those seen in late onset AD even during the preclinical period including lower levels of NAA and higher levels of mI. These indices of neuronal and glial dysfunction might serve as surrogate outcome measures in prevention studies of putative disease-modifying agents.

  5. Pre-clinical toxicology considerations for vaccine development.

    PubMed

    Al-Humadi, Nabil

    2017-10-13

    Vaccine development requires pre-clinical toxicology studies, following good laboratory practice (GLP), before first in human (phase I) use. Many factors are critical in the final outcome of any pre-clinical toxicology study. The study design is one of these critical factors and should be carefully planned to avoid any false negative and/or false positive results. Preparation is another most critical factor in a successful study. Major changes in any procedure during the course of study should be avoided by all means. For example, if the protocol specified the tail as the site of blood collection and this procedure was used for the control group at the day of necropsy, this collection site should never be replaced by another site (e.g. foot, eye, or heart) in all other treatment groups. Food restrictions and acute restraint stress affect clinical pathology data and should be avoided in rodents. Institutional Animal Care and Use Committee (IACUC) guidelines for frequent blood collections (weekly, monthly, or at necropsy) in any animal species should be strictly followed. Clinical pathology data will be profoundly affected by any diversion from the recommended volumes. If CO 2 is specified in the protocol for anesthesia and/or euthanasia, ensuring enough quantity to use for all groups at necropsy is a very important factor. Using two different anesthetics in any study (e.g. CO 2 vs. pentobarbital) may result in false positive or false negative results in clinical chemistry parameters. Quality assurance elements (SOPs, instrument validation, lab certification etc.) affect the data interpretation and the final outcome of any toxicology study. SOPs should be up to date and written clearly. All lab instruments should be validated and all laboratories should be certified. Published by Elsevier Ltd.

  6. Enhancing preclinical year pathology exposure: the Angevine approach.

    PubMed

    Brooks, Erin G; Paus, Amanda M; Corliss, Robert F; Ranheim, Erik A

    2016-07-01

    Less than 2% of graduating US medical seniors select pathology residencies. One major obstacle to attracting prospective residents is the relative "invisibility" of pathology; medical students lacking positive preclinical exposure to pathology are unlikely to later select pathology clerkships or residencies. The Angevine Fellowship is a 10-week competitive pathology internship medical students may apply for the summer following their first year of preclinical training at our institution. We sought to determine whether it was an effective pathology recruitment tool and how it compared with the postsophomore pathology fellowship (PSF). Angevine fellow and PSF data from 2000 to 2014 were retrospectively analyzed. Specialty choices of former fellows already matched into residency programs were tabulated. Data regarding annual percentage of graduating seniors at our institution who matched into pathology during the years former fellow cohorts matched were also examined. Our results showed that of the former Angevine fellow cohorts already matched into residency programs, 40% (8/20) matched in pathology and 20% (4/20) at our own institution. Angevine fellows comprised a disproportionately high number of the graduating seniors matching in pathology at our medical school (26.7%). PSFs comprised 6.67%. Although we have endowment funding for 2 Angevine fellows annually, the level of interest among applicants has increased to the point that our department has consistently contributed funding for 1-2 additional fellowship spots since 2011. We conclude that the Angevine Fellowship offers an effective alternative to the postsophomore fellowship. It has proven successful at our institution and could be implemented at others to potentially improve pathology recruitment trends nationwide. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Preclinical carotid atherosclerosis in patients with rheumatoid arthritis.

    PubMed

    Roman, Mary J; Moeller, Elfi; Davis, Adrienne; Paget, Stephen A; Crow, Mary K; Lockshin, Michael D; Sammaritano, Lisa; Devereux, Richard B; Schwartz, Joseph E; Levine, Daniel M; Salmon, Jane E

    2006-02-21

    Rheumatoid arthritis is associated with increased morbidity and mortality because of cardiovascular disease, independent of traditional risk factors. To determine the prevalence of preclinical atherosclerosis in patients with rheumatoid arthritis and to identify clinical and biological markers for atherosclerotic disease in this patient population. Matched, cross-sectional study. Hospital for Special Surgery in New York City. 98 consecutive outpatients with rheumatoid arthritis who were followed by rheumatologists and 98 controls matched on age, sex, and ethnicity. Cardiovascular risk factor ascertainment and carotid ultrasonography in all participants; disease severity, disease treatment, and inflammatory markers in patients with rheumatoid arthritis. Despite a more favorable risk factor profile, patients with rheumatoid arthritis had a 3-fold increase in carotid atherosclerotic plaque (44% vs. 15%; P < 0.001). The relationship between rheumatoid arthritis and carotid atherosclerotic plaque remained after accounting for age, serum cholesterol levels, smoking history, and hypertensive status; adjusted predicted prevalence was 7.4% (95% CI, 3.4% to 15.2%) for the control group and 38.5% (CI, 25.4% to 53.5%) for patients with rheumatoid arthritis. Age (P < 0.001) and current cigarette use (P < 0.014) were also significantly associated with carotid atherosclerotic plaque. Among patients with rheumatoid arthritis, atherosclerosis was related to age, hypertension status, and use of tumor necrosis factor-alpha inhibitors (a possible marker of disease severity). The study had a cross-sectional design, and inflammatory markers were determined only once. Patients with rheumatoid arthritis have a high prevalence of preclinical atherosclerosis independent of traditional risk factors, suggesting that chronic inflammation and, possibly, disease severity are atherogenic in this population.

  8. Establishing a Th17 based mouse model for preclinical assessment of the toxicity of candidate microbicides.

    PubMed

    Li, Liang-Zhu; Yang, Yu; Yuan, Song-Hua; Wan, Yan-Min; Qiu, Chao; Feng, Yan-Ling; Xu, Jian-Qing; Zhang, Xiao-Yan

    2010-12-01

    To effectively block the invasion of human immunodeficiency virus (HIV)-1 on mucosal surface, vaginal anti-HIV-1 microbicides should avoid inflammatory responses and disruption of mucosa integrity because these will facilitate transepithelial viral penetration and replication. However, existing models fail to predict and evaluate vaginal mucosal toxicity induced by microbicides, and most importantly, they are unable to identify subtle or subclinical inflammatory reactions. This study was designed to develop a cost-effective in vivo model to evaluate microbicide safety in a preclinical study which can recapitulate the mucosal topical reaction. A murine model was employed with nonoxynol-9 (N-9) as the topical stimulant within the vagina. Different concentrations of N-9 (1%, 3%, and 4%) were topically applied to the vagina for five consecutive days. A panel of inflammatory cytokines including interleukine-2 (IL-2), IL-4, IL-6, IL-17A, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and immuno-regulatory IL-10 were assayed in vaginal lavage. Cytokines were quantified by using cytometric bead array (CBA) and reverse transcript (RT) real-time PCR. Histopathological evaluation of vaginal tissues was conducted on hematoxylin-eosin stained slides and scored with a semi-quantitative system according to the severity of epithelial disruption, leucocyte infiltration, edema, and vascular injection. The association between the cytokines and histopathological scores was assessed by linear regression analysis. All three concentrations of N-9 induced inflammatory cytokine production. The 4% N-9 application resulted in a consistent production of cytokines in a time-dependent manner. The cytokines reached peak expression on day three with the exception of IL-4 which reached its peak on day one. Histopathological examination of 4% N-9 treated cervicovaginal tissues on day three showed intensive damage in four mice (sores: 10 - 13) and moderate damage in one mouse (score: 8

  9. Methodological Aspects for Preclinical Evaluation of Gadolinium Presence in Brain Tissue: Critical Appraisal and Suggestions for Harmonization-A Joint Initiative.

    PubMed

    Robert, Philippe; Frenzel, Thomas; Factor, Cécile; Jost, Gregor; Rasschaert, Marlène; Schuetz, Gunnar; Fretellier, Nathalie; Boyken, Janina; Idée, Jean-Marc; Pietsch, Hubertus

    2018-04-13

    Gadolinium (Gd)-based contrast agents (GBCAs) are pharmaceuticals that have been approved for 30 years and used daily in millions of patients worldwide. Their clinical benefits are indisputable. Recently, unexpected long-term presence of Gd in the brain has been reported by numerous retrospective clinical studies and confirmed in preclinical models particularly after linear GBCA (L-GBCA) compared with macrocyclic GBCA (M-GBCA). Even if no clinical consequences of Gd presence in brain tissue has been demonstrated so far, in-depth investigations on potential toxicological consequences and the fate of Gd in the body remain crucial to potentially adapt the clinical use of GBCAs, as done during the nephrogenic systemic fibrosis crisis. Preclinical models are instrumental in the understanding of the mechanism of action as well as the potential safety consequences. However, such models may be associated with risks of biases, often related to the protocol design. Selection of adequate terminology is also crucial. This review of the literature intends to summarize and critically discuss the main methodological aspects for accurate design and translational character of preclinical studies.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

  10. Biochemical characterization and structural insight into aliphatic β-amino acid adenylation enzymes IdnL1 and CmiS6.

    PubMed

    Cieślak, Jolanta; Miyanaga, Akimasa; Takaku, Ryoma; Takaishi, Makoto; Amagai, Keita; Kudo, Fumitaka; Eguchi, Tadashi

    2017-07-01

    Macrolactam antibiotics such as incednine and cremimycin possess an aliphatic β-amino acid as a starter unit of their polyketide chain. In the biosynthesis of incednine and cremimycin, unique stand-alone adenylation enzymes IdnL1 and CmiS6 select and activate the proper aliphatic β-amino acid as a starter unit. In this study, we describe the enzymatic characterization and the structural basis of substrate specificity of IdnL1 and CmiS6. Functional analysis revealed that IdnL1 and CmiS6 recognize 3-aminobutanoic acid and 3-aminononanoic acid, respectively. We solved the X-ray crystal structures of IdnL1 and CmiS6 to understand the recognition mechanism of these aliphatic β-amino acids. These structures revealed that IdnL1 and CmiS6 share a common recognition motif that interacts with the β-amino group of the substrates. However, the hydrophobic side-chains of the substrates are accommodated differently in the two enzymes. IdnL1 has a bulky Leu220 located close to the terminal methyl group of 3-aminobutanoate of the trapped acyl-adenylate intermediate to construct a shallow substrate-binding pocket. In contrast, CmiS6 possesses Gly220 at the corresponding position to accommodate 3-aminononanoic acid. This structural observation was supported by a mutational study. Thus, the size of amino acid residue at the 220 position is critical for the selection of an aliphatic β-amino acid substrate in these adenylation enzymes. Proteins 2017; 85:1238-1247. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. Targeting of hyperactivated mTOR signaling in high-risk acute lymphoblastic leukemia in a pre-clinical model.

    PubMed

    Hasan, Md Nabiul; Queudeville, Manon; Trentin, Luca; Eckhoff, Sarah Mirjam; Bronzini, Ilaria; Palmi, Chiara; Barth, Thomas; Cazzaniga, Giovanni; te Kronnie, Geertruy; Debatin, Klaus-Michael; Meyer, Lüder Hinrich

    2015-01-30

    Despite increasingly successful treatment of pediatric ALL, up to 20% of patients encounter relapse. By current biomarkers, the majority of relapse patients is initially not identified indicating the need for prognostic and therapeutic targets reflecting leukemia biology. We previously described that rapid engraftment of patient ALL cells transplanted onto NOD/SCID mice (short time to leukemia, TTLshort) is indicative of early patient relapse. Gene expression profiling identified genes coding for molecules involved in mTOR signaling to be associated with TTLshort/early relapse leukemia. Here, we now functionally address mTOR signaling activity in primograft ALL samples and evaluate mTOR pathway inhibition as novel treatment strategy for high-risk ALL ex vivo and in vivo. By analysis of S6-phosphorylation downstream of mTOR, increased mTOR activation was found in TTLshort/high-risk ALL, which was effectively abrogated by mTOR inhibitors resulting in decreased leukemia proliferation and growth. In a preclinical setting treating individual patient-derived ALL in vivo, mTOR inhibition alone, and even more pronounced together with conventional remission induction therapy, significantly delayed post-treatment leukemia reoccurrence in TTLshort/high-risk ALL. Thus, the TTLshort phenotype is functionally characterized by hyperactivated mTOR signaling and can effectively be targeted ex vivo and in vivo providing a novel therapeutic strategy for high-risk ALL.

  12. Targeting TORC1/2 enhances sensitivity to EGFR inhibitors in head and neck cancer preclinical models.

    PubMed

    Cassell, Andre; Freilino, Maria L; Lee, Jessica; Barr, Sharon; Wang, Lin; Panahandeh, Mary C; Thomas, Sufi M; Grandis, Jennifer R

    2012-11-01

    Head and neck squamous cell carcinoma (HNSCC) is characterized by overexpression of the epidermal growth factor receptor (EGFR) where treatments targeting EGFR have met with limited clinical success. Elucidation of the key downstream-pathways that remain activated in the setting of EGFR blockade may reveal new therapeutic targets. The present study was undertaken to test the hypothesis that inhibition of the mammalian target of rapamycin (mTOR) complex would enhance the effects of EGFR blockade in HNSCC preclinical models. Treatment of HNSCC cell lines with the newly developed TORC1/TORC2 inhibitor OSI-027/ASP4876 resulted in dose-dependent inhibition of proliferation with abrogation of phosphorylation of known downstream targets including phospho-AKT (Ser473), phospho-4E-BP1, phospho-p70s6K, and phospho-PRAS40. Furthermore, combined treatment with OSI-027 and erlotinib resulted in enhanced biochemical effects and synergistic growth inhibition in vitro. Treatment of mice bearing HNSCC xenografts with a combination of the Food and Drug Administration (FDA)-approved EGFR inhibitor cetuximab and OSI-027 demonstrated a significant reduction of tumor volumes compared with either treatment alone. These findings suggest that TORC1/TORC2 inhibition in conjunction with EGFR blockade represents a plausible therapeutic strategy for HNSCC.

  13. Targeting TORC1/2 Enhances Sensitivity to EGFR Inhibitors in Head and Neck Cancer Preclinical Models1

    PubMed Central

    Cassell, Andre; Freilino, Maria L; Lee, Jessica; Barr, Sharon; Wang, Lin; Panahandeh, Mary C; Thomas, Sufi M; Grandis, Jennifer R

    2012-01-01

    Head and neck squamous cell carcinoma (HNSCC) is characterized by overexpression of the epidermal growth factor receptor (EGFR) where treatments targeting EGFR have met with limited clinical success. Elucidation of the key downstream-pathways that remain activated in the setting of EGFR blockade may reveal new therapeutic targets. The present study was undertaken to test the hypothesis that inhibition of the mammalian target of rapamycin (mTOR) complex would enhance the effects of EGFR blockade in HNSCC preclinical models. Treatment of HNSCC cell lines with the newly developed TORC1/TORC2 inhibitor OSI-027/ASP4876 resulted in dose-dependent inhibition of proliferation with abrogation of phosphorylation of known downstream targets including phospho-AKT (Ser473), phospho-4E-BP1, phospho-p70s6K, and phospho-PRAS40. Furthermore, combined treatment with OSI-027 and erlotinib resulted in enhanced biochemical effects and synergistic growth inhibition in vitro. Treatment of mice bearing HNSCC xenografts with a combination of the Food and Drug Administration (FDA)-approved EGFR inhibitor cetuximab and OSI-027 demonstrated a significant reduction of tumor volumes compared with either treatment alone. These findings suggest that TORC1/TORC2 inhibition in conjunction with EGFR blockade represents a plausible therapeutic strategy for HNSCC. PMID:23226094

  14. Phosphorylation of Ribosomal Protein S6 Kinase 1 at Thr421/Ser424 and Dephosphorylation at Thr389 Regulates SP600125-Induced Polyploidization of Megakaryocytic Cell Lines

    PubMed Central

    Lin, Di; Zhao, Yong-Shan; Liu, Shuo; Xing, Si-Ning; Zhao, Song; Chen, Cong-Qin; Jiang, Zhi-Ming; Pu, Fei-Fei; Cao, Jian-Ping; Ma, Dong-Chu

    2014-01-01

    Megakaryocytes (MKs) are one of the few cell types that become polyploid; however, the mechanisms by which these cells are designated to become polyploid are not fully understood. In this investigation, we successfully established two relatively synchronous polyploid cell models by inducing Dami and CMK cells with SP600125. We found that SP600125 induced the polyploidization of Dami and CMK cells, concomitant with the phosphorylation of ribosomal protein S6 kinase 1 (S6K1) at Thr421/Ser424 and dephosphorylation at Thr389. The polyploidization was partially blocked by H-89, a cAMP-dependent protein kinase (PKA) inhibitor, through direct binding to S6K1, leading to dephosphorylation at Thr421/Ser424 and phosphorylation at Thr389, independent of PKA. Overexpression of a rapamycin-resistant mutant of S6K1 further enhanced the inhibitory effect of LY294002 on the SP600125-induced polyploidization of Dami and CMK cells. SP600125 also induced the polyploidization of Meg-01 cells, which are derived from a patient with chronic myelogenous leukemia, without causing a significant change in S6K1 phosphorylation. Additionally, SP600125 induced the polyploidization of HEL cells, which are derived from a patient with erythroleukemia, and phosphorylation at Thr389 of S6K1 was detected. However, the polyploidization of both Meg-01 cells and HEL cells as a result of SP600125 treatment was lower than that of SP600125-induced Dami and CMK cells, and it was not blocked by H-89 despite the increased phosphorylation of S6K1 at Thr389 in both cell lines in response to H-89. Given that the Dami and CMK cell lines were derived from patients with acute megakaryocytic leukemia (AMKL) and expressed high levels of platelet-specific antigens, our data suggested that SP600125-induced polyploidization is cell-type specific, that these cell lines were more differentiated, and that phosphorylation at Thr421/Ser424 and dephosphorylation at Thr389 of S6K1 may play an important role in the SP600125

  15. Phosphorylation of ribosomal protein S6 kinase 1 at Thr421/Ser424 and dephosphorylation at Thr389 regulates SP600125-induced polyploidization of megakaryocytic cell lines.

    PubMed

    Li, Chang-Ling; Yang, Jin-Gang; Lin, Di; Zhao, Yong-Shan; Liu, Shuo; Xing, Si-Ning; Zhao, Song; Chen, Cong-Qin; Jiang, Zhi-Ming; Pu, Fei-Fei; Cao, Jian-Ping; Ma, Dong-Chu

    2014-01-01

    Megakaryocytes (MKs) are one of the few cell types that become polyploid; however, the mechanisms by which these cells are designated to become polyploid are not fully understood. In this investigation, we successfully established two relatively synchronous polyploid cell models by inducing Dami and CMK cells with SP600125. We found that SP600125 induced the polyploidization of Dami and CMK cells, concomitant with the phosphorylation of ribosomal protein S6 kinase 1 (S6K1) at Thr421/Ser424 and dephosphorylation at Thr389. The polyploidization was partially blocked by H-89, a cAMP-dependent protein kinase (PKA) inhibitor, through direct binding to S6K1, leading to dephosphorylation at Thr421/Ser424 and phosphorylation at Thr389, independent of PKA. Overexpression of a rapamycin-resistant mutant of S6K1 further enhanced the inhibitory effect of LY294002 on the SP600125-induced polyploidization of Dami and CMK cells. SP600125 also induced the polyploidization of Meg-01 cells, which are derived from a patient with chronic myelogenous leukemia, without causing a significant change in S6K1 phosphorylation. Additionally, SP600125 induced the polyploidization of HEL cells, which are derived from a patient with erythroleukemia, and phosphorylation at Thr389 of S6K1 was detected. However, the polyploidization of both Meg-01 cells and HEL cells as a result of SP600125 treatment was lower than that of SP600125-induced Dami and CMK cells, and it was not blocked by H-89 despite the increased phosphorylation of S6K1 at Thr389 in both cell lines in response to H-89. Given that the Dami and CMK cell lines were derived from patients with acute megakaryocytic leukemia (AMKL) and expressed high levels of platelet-specific antigens, our data suggested that SP600125-induced polyploidization is cell-type specific, that these cell lines were more differentiated, and that phosphorylation at Thr421/Ser424 and dephosphorylation at Thr389 of S6K1 may play an important role in the SP600125

  16. Tuberous sclerosis complex tumor suppressor–mediated S6 kinase inhibition by phosphatidylinositide-3-OH kinase is mTOR independent

    PubMed Central

    Jaeschke, Anja; Hartkamp, Joerg; Saitoh, Masao; Roworth, Wendy; Nobukuni, Takahiro; Hodges, Angela; Sampson, Julian; Thomas, George; Lamb, Richard

    2002-01-01

    The evolution of mitogenic pathways has led to the parallel requirement for negative control mechanisms, which prevent aberrant growth and the development of cancer. Principally, such negative control mechanisms are represented by tumor suppressor genes, which normally act to constrain cell proliferation (Macleod, K. 2000. Curr. Opin. Genet. Dev. 10:81–93). Tuberous sclerosis complex (TSC) is an autosomal-dominant genetic disorder, characterized by mutations in either TSC1 or TSC2, whose gene products hamartin (TSC1) and tuberin (TSC2) constitute a putative tumor suppressor complex (TSC1-2; van Slegtenhorst, M., M. Nellist, B. Nagelkerken, J. Cheadle, R. Snell, A. van den Ouweland, A. Reuser, J. Sampson, D. Halley, and P. van der Sluijs. 1998. Hum. Mol. Genet. 7:1053–1057). Little is known with regard to the oncogenic target of TSC1-2, however recent genetic studies in Drosophila have shown that S6 kinase (S6K) is epistatically dominant to TSC1-2 (Tapon, N., N. Ito, B.J. Dickson, J.E. Treisman, and I.K. Hariharan. 2001. Cell. 105:345–355; Potter, C.J., H. Huang, and T. Xu. 2001. Cell. 105:357–368). Here we show that loss of TSC2 function in mammalian cells leads to constitutive S6K1 activation, whereas ectopic expression of TSC1-2 blocks this response. Although activation of wild-type S6K1 and cell proliferation in TSC2-deficient cells is dependent on the mammalian target of rapamycin (mTOR), by using an S6K1 variant (GST-ΔC-S6K1), which is uncoupled from mTOR signaling, we demonstrate that TSC1-2 does not inhibit S6K1 via mTOR. Instead, we show by using wortmannin and dominant interfering alleles of phosphatidylinositide-3-OH kinase (PI3K) that increased S6K1 activation is contingent upon the suppression of TSC2 function by PI3K in normal cells and is PI3K independent in TSC2-deficient cells. PMID:12403809

  17. The importance of imaging strategies for pre-clinical and clinical in vivo distribution of oncolytic viruses

    PubMed Central

    Pelin, Adrian; Wang, Jiahu; Bell, John; Le Boeuf, Fabrice

    2017-01-01

    Oncolytic viruses (OVs) are an emergent and unique therapy for cancer patients. Similar to chemo- and radiation therapy, OV can lyse (kill) cancer cell directly. In general, the advantages of OVs over other treatments are primarily: a higher safety profile (as shown by less adverse effects), ability to replicate, transgene(s) delivery, and stimulation of a host’s immune system against cancer. The latter has prompted successful use of OVs with other immunotherapeutic strategies in a synergistic manner. In spite of extended testing in pre-clinical and clinical setting, using biologically derived therapeutics like virus always raises potential concerns about safety (replication at non-intended locations) and bio-availability of the product. Recent advent in in vivo imaging techniques dramatically improves the convenience of use, quality of pictures, and amount of information acquired. Easy assessing of safety/localization of the biotherapeutics like OVs became a new potential weapon in the physician’s arsenal to improve treatment outcome. Given that OVs are typically replicating, in vivo imaging can also track virus replication and persistence as well as precisely mapping tumor tissues presence. This review discusses the importance of imaging in vivo in evaluating OV efficacy, as well as currently available tools and techniques. PMID:29637059

  18. Investigative safety science as a competitive advantage for Pharma.

    PubMed

    Moggs, Jonathan; Moulin, Pierre; Pognan, Francois; Brees, Dominique; Leonard, Michele; Busch, Steve; Cordier, Andre; Heard, David J; Kammüller, Michael; Merz, Michael; Bouchard, Page; Chibout, Salah-Dine

    2012-09-01

    Following a US National Academy of Sciences report in 2007 entitled "Toxicity Testing of the 21st Century: a Vision and a Strategy," significant advances within translational drug safety sciences promise to revolutionize drug discovery and development. The purpose of this review is to outline why investigative safety science is a competitive advantage for the pharmaceutical industry. The article discusses the essential goals for modern investigative toxicologists including: cross-species target biology; molecular pathways of toxicity; and development of predictive tools, models and biomarkers that allow discovery researchers and clinicians to anticipate safety problems and plan ways to address them, earlier than ever before. Furthermore, the article emphasizes the importance of investigating unanticipated clinical safety signals through a combination of mechanistic preclinical studies and/or molecular characterization of clinical samples from affected organs. The traditional boundaries between pharma industry teams focusing on safety/efficacy and preclinical/clinical development are rapidly disappearing in favor of translational safety science-centric organizations with a vision of bringing more effective medicines forward safely and quickly. Comparative biology and mechanistic toxicology approaches facilitate: i) identifying translational safety biomarkers; ii) identifying new drug targets/indications; and iii) mitigating off-target toxicities. These value-adding safety science contributions will change traditional toxicologists from side-effect identifiers to drug development enablers.

  19. Auto Safety

    MedlinePlus

    ... certified child passenger safety technician to assist you.) Guidelines for Choosing a Safety Seat Choose a seat ... and are between 8 and 12 years old. Guidelines for Choosing a Booster Seat Choose a seat ...

  20. Water Safety

    MedlinePlus

    ... Staying Safe Videos for Educators Search English Español Water Safety KidsHealth / For Parents / Water Safety What's in ... remains your best measure of protection. Making Kids Water Wise It's important to teach your kids proper ...

  1. Water Safety

    MedlinePlus

    ... Staying Safe Videos for Educators Search English Español Water Safety KidsHealth / For Teens / Water Safety What's in ... drownings are tied to alcohol use. At the Water Park OK, so you do more splashing than ...

  2. Sun Safety

    MedlinePlus

    ... the Sun? Are There Benefits to Spending Time Outdoors? Statistics Behavior Rates Sun Safety Tips for Men ... and yourself from skin cancer. Stay sun-safe outdoors and discourage indoor and outdoor tanning. Sun Safety ...

  3. Aggregation of Ribosomal Protein S6 at Nucleolus Is Cell Cycle-Controlled and Its Function in Pre-rRNA Processing Is Phosphorylation Dependent.

    PubMed

    Zhang, Duo; Chen, Hui-Peng; Duan, Hai-Feng; Gao, Li-Hua; Shao, Yong; Chen, Ke-Yan; Wang, You-Liang; Lan, Feng-Hua; Hu, Xian-Wen

    2016-07-01

    Ribosomal protein S6 (rpS6) has long been regarded as one of the primary r-proteins that functions in the early stage of 40S subunit assembly, but its actual role is still obscure. The correct forming of 18S rRNA is a key step in the nuclear synthesis of 40S subunit. In this study, we demonstrate that rpS6 participates in the processing of 30S pre-rRNA to 18S rRNA only when its C-terminal five serines are phosphorylated, however, the process of entering the nucleus and then targeting the nucleolus does not dependent its phosphorylation. Remarkably, we also find that the aggregation of rpS6 at the nucleolus correlates to the phasing of cell cycle, beginning to concentrate in the nucleolus at later S phase and disaggregate at M phase. J. Cell. Biochem. 117: 1649-1657, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  4. Magic wavelengths for the 6{s}^{2}{}^{1}{S}_{0}{--}6s6p{}^{3}{P}_{1}^{o} transition in ytterbium atom

    NASA Astrophysics Data System (ADS)

    Tang, Zhi-Ming; Yu, Yan-Mei; Jiang, Jun; Dong, Chen-Zhong

    2018-06-01

    The static and dynamic electric dipole polarizabilities of the 6{s}2{}1{S}0 and 6s6p{}3{P}1o states of Yb are calculated by using the relativistic ab initio method. Focusing on the red detuning region to the 6{s}2{}1{S}0{--}6s6p{}3{P}1o transition, we find two magic wavelengths at 1035.7(2) and 612.9(2) nm for the 6{s}2{}1{S}0{--}6s6p{}3{P}1o,{M}J=0 transition and three magic wavelengths at 1517.68(6), 1036.0(3) and 858(12) nm for the 6{s}2{}1{S}0{--}6s6p{}3{P}1o,{M}J=+/- 1 transitions. Such magic wavelengths are of particular interest for attaining the state-insensitive cooling, trapping, and quantum manipulation of neutral Yb atom.

  5. Synthesis, structural, electronic and linear electro-optical features of new quaternary Ag2Ga2SiS6 compound

    NASA Astrophysics Data System (ADS)

    Piasecki, M.; Myronchuk, G. L.; Parasyuk, O. V.; Khyzhun, O. Y.; Fedorchuk, A. O.; Pavlyuk, V. V.; Kozer, V. R.; Sachanyuk, V. P.; El-Naggar, A. M.; Albassam, A. A.; Jedryka, J.; Kityk, I. V.

    2017-02-01

    For the first time phase equilibria and phase diagram of the AgGaS2-SiS2 system were successfully explored by differential thermal and X-ray phase analysis methods. Crystal structure of low-temperature (LT) modification of Ag2Ga2SiS6 (LT- Ag2Ga2SiS6) was studied by X-ray powder method and it belongs to tetragonal space group I-42d, with unit cell parameters a=5.7164(4) Å, c=9.8023(7) Å, V=320.32(7) Å3. Additional details regarding the crystal structure exploration are available at the web page Fachinformationszentrum Karlsruhe. X-ray photoelectron core-level and valence-band spectra were measured for pristine LT- Ag2Ga2SiS6 crystal surface. In addition, the X-ray photoelectron valence-band spectrum of LT-Ag2Ga2SiS6 was matched on a common energy scale with the X-ray emission S Kβ1,3 and Ga Kβ2 bands, which give information on the energy distribution of the S 3p and Ga 4p states, respectively. The presented X-ray spectroscopy results indicate that the valence S p and Ga p atomic states contribute mainly to the upper and central parts of the valence band of LT-Ag2Ga2SiS6, respectively, with a less significant contribution also to other valence-band regions. Band gap energy was estimated by measuring the quantum energy in the spectral range of the fundamental absorption. We have found that energy gap Eg is equal to 2.35 eV at 300 K. LT-Ag2Ga2SiS6 is a photosensitive material and reveals two spectral maxima on the curve of spectral photoconductivity spectra at λmax1 =590 nm and λmax2 =860 nm. Additionally, linear electro-optical effect of LT-Ag2Ga2SiS6 for the wavelengths of a cw He-Ne laser at 1150 nm was explored.

  6. [SP600125-induced polyploidization of megakaryocytic leukemia cell lines by ribosomal protein S6 kinase 1 depends on the degree of cell differentiation].

    PubMed

    Wang, Lili; Yang, Jingang; Li, Changling; Xing, Sining; Yu, Ying; Liu, Shuo; Zhao, Song; Ma, Dongchu

    2016-10-01

    Objective To investigate regulatory role of ribosomal protein S6 kinase 1 (S6K1) in the polyploidization of different megakaryocytic leukemia cell lines at the different differentiation stages. Methods Megakaryocytic leukemia cell lines (Dami, Meg-01 and HEL cells) were induced towards polyploidization by SP600125, a c-Jun N-terminal kinase (JNK) inhibitor. The SP600125-inducing process was blocked by H-89, a cAMP-dependent protein kinase (PKA) inhibitor. The phenotype (CD41a, CD42a and CD42b) and DNA ploidy were detected by flow cytometry. The expression and phosphorylation of S6K1 and related proteins were detected by Western blotting. Results SP600125 induced polyploidization and increased the phosphorylation of eukaryotic initiation factor 4E binding protein 1 (4E-BP1) in Dami, Meg-01 and HEL cells. However, the effect of SP600125 on polyploidization of the three cell lines was different, with the strongest effect on Dami cells and the weakest on Meg-01 cells. Moreover, SP600125 increased the phosphorylation of S6K1 Thr421/Ser424 and decreased the phosphorylation of Thr389 in Dami cells. However, it only increased the phosphorylation of Thr389 in HEL cells and had no effect on the phosphorylation of S6K1 in Meg-01 cells. Interestingly, H-89 only partially blocked the polyploidization of Dami cells, although it decreased the phosphorylation of 4E-BP1 in all SP600125-induced three cell lines. Noticeably, H-89 decreased the phosphorylation of S6K1 Thr421/Ser424 and increased the phosphorylation of Thr389 in Dami cells. However, H-89 had no effect on the phosphorylation of Thr421/Ser424, although it increased the phosphorylation of Thr389 in Meg-01 and HEL cells. Phenotypic analysis showed that the three cell lines were at different levels of differentiation in megakaryocytic lineage, with the highest differentiation in Dami and the lowest in Meg-01 cells. Conclusion SP600125-induced polyploidization of megakaryocytic leukemia cell lines is dependent on the effect

  7. MIDG-Emerging grid technologies for multi-site preclinical molecular imaging research communities.

    PubMed

    Lee, Jasper; Documet, Jorge; Liu, Brent; Park, Ryan; Tank, Archana; Huang, H K

    2011-03-01

    Molecular imaging is the visualization and identification of specific molecules in anatomy for insight into metabolic pathways, tissue consistency, and tracing of solute transport mechanisms. This paper presents the Molecular Imaging Data Grid (MIDG) which utilizes emerging grid technologies in preclinical molecular imaging to facilitate data sharing and discovery between preclinical molecular imaging facilities and their collaborating investigator institutions to expedite translational sciences research. Grid-enabled archiving, management, and distribution of animal-model imaging datasets help preclinical investigators to monitor, access and share their imaging data remotely, and promote preclinical imaging facilities to share published imaging datasets as resources for new investigators. The system architecture of the Molecular Imaging Data Grid is described in a four layer diagram. A data model for preclinical molecular imaging datasets is also presented based on imaging modalities currently used in a molecular imaging center. The MIDG system components and connectivity are presented. And finally, the workflow steps for grid-based archiving, management, and retrieval of preclincial molecular imaging data are described. Initial performance tests of the Molecular Imaging Data Grid system have been conducted at the USC IPILab using dedicated VMware servers. System connectivity, evaluated datasets, and preliminary results are presented. The results show the system's feasibility, limitations, direction of future research. Translational and interdisciplinary research in medicine is increasingly interested in cellular and molecular biology activity at the preclinical levels, utilizing molecular imaging methods on animal models. The task of integrated archiving, management, and distribution of these preclinical molecular imaging datasets at preclinical molecular imaging facilities is challenging due to disparate imaging systems and multiple off-site investigators. A

  8. Does student performance on preclinical OSCEs relate to clerkship grades?

    PubMed

    Chima, Margot; Dallaghan, Gary Beck

    2016-01-01

    Objective structured clinical examinations (OSCEs) have been used to assess the clinical competence and interpersonal skills of healthcare professional students for decades. However, the relationship between preclinical (second year or M2) OSCE grades and clerkship performance had never been evaluated, until it was explored to provide information to educators at the University of Nebraska Medical Center (UNMC). In addition, the relationship between M2 OSCE communication scores (which is a portion of the total score) and third-year (M3) Internal Medicine (IM) clerkship OSCE scores was also explored. Lastly, conflicting evidence exists about the relationship between the amount of previous clinical experience and OSCE performance. Therefore, the relationship between M3 IM clerkship OSCE scores and the timing of the clerkship in the academic year was explored. Data from UNMC M2 OSCEs and M3 IM clerkship OSCEs were obtained for graduates of the 2013 and 2014 classes. Specifically, the following data points were collected: M2 fall OSCE total, M2 fall OSCE communication; M2 spring OSCE total, M2 spring OSCE communication; and M3 IM clerkship OSCE total percentages. Data were organized by class, M3 IM clerkship OSCE performance, and timing of the clerkship. Microsoft Excel and SPSS were used for data organization and analysis. Of the 245 records, 229 (93.5%) had data points for all metrics of interest. Significant differences between the classes of 2013 and 2014 existed for average M2 spring total, M2 spring communication, and M3 IM clerkship OSCEs. Retrospectively, there were no differences in M2 OSCE performances based on how students scored on the M3 IM clerkship OSCE. M3 IM clerkship OSCE performance improved for those students who completed the clerkship last in the academic year. There were inconsistencies in OSCE performances between the classes of 2013 and 2014, but more information is needed to determine if this is because of testing variability or heterogeneity

  9. Preclinical imaging characteristics and quantification of Platinum-195m SPECT.

    PubMed

    Aalbersberg, E A; de Wit-van der Veen, B J; Zwaagstra, O; Codée-van der Schilden, K; Vegt, E; Vogel, Wouter V

    2017-08-01

    In vivo biodistribution imaging of platinum-based compounds may allow better patient selection for treatment with chemo(radio)therapy. Radiolabeling with Platinum-195m ( 195m Pt) allows SPECT imaging, without altering the chemical structure or biological activity of the compound. We have assessed the feasibility of 195m Pt SPECT imaging in mice, with the aim to determine the image quality and accuracy of quantification for current preclinical imaging equipment. Enriched (>96%) 194 Pt was irradiated in the High Flux Reactor (HFR) in Petten, The Netherlands (NRG). A 0.05 M HCl 195m Pt-solution with a specific activity of 33 MBq/mg was obtained. Image quality was assessed for the NanoSPECT/CT (Bioscan Inc., Washington DC, USA) and U-SPECT + /CT (MILabs BV, Utrecht, the Netherlands) scanners. A radioactivity-filled rod phantom (rod diameter 0.85-1.7 mm) filled with 1 MBq 195m Pt was scanned with different acquisition durations (10-120 min). Four healthy mice were injected intravenously with 3-4 MBq 195m Pt. Mouse images were acquired with the NanoSPECT for 120 min at 0, 2, 4, or 24 h after injection. Organs were delineated to quantify 195m Pt concentrations. Immediately after scanning, the mice were sacrificed, and the platinum concentration was determined in organs using a gamma counter and graphite furnace - atomic absorption spectroscopy (GF-AAS) as reference standards. A 30-min acquisition of the phantom provided visually adequate image quality for both scanners. The smallest visible rods were 0.95 mm in diameter on the NanoSPECT and 0.85 mm in diameter on the U-SPECT + . The image quality in mice was visually adequate. Uptake was seen in the kidneys with excretion to the bladder, and in the liver, blood, and intestine. No uptake was seen in the brain. The Spearman correlation between SPECT and gamma counter was 0.92, between SPECT and GF-AAS it was 0.84, and between GF-AAS and gamma counter it was0.97 (all p < 0.0001). Preclinical 195m Pt SPECT is

  10. Does student performance on preclinical OSCEs relate to clerkship grades?

    PubMed Central

    Chima, Margot; Dallaghan, Gary Beck

    2016-01-01

    Background Objective structured clinical examinations (OSCEs) have been used to assess the clinical competence and interpersonal skills of healthcare professional students for decades. However, the relationship between preclinical (second year or M2) OSCE grades and clerkship performance had never been evaluated, until it was explored to provide information to educators at the University of Nebraska Medical Center (UNMC). In addition, the relationship between M2 OSCE communication scores (which is a portion of the total score) and third-year (M3) Internal Medicine (IM) clerkship OSCE scores was also explored. Lastly, conflicting evidence exists about the relationship between the amount of previous clinical experience and OSCE performance. Therefore, the relationship between M3 IM clerkship OSCE scores and the timing of the clerkship in the academic year was explored. Methods Data from UNMC M2 OSCEs and M3 IM clerkship OSCEs were obtained for graduates of the 2013 and 2014 classes. Specifically, the following data points were collected: M2 fall OSCE total, M2 fall OSCE communication; M2 spring OSCE total, M2 spring OSCE communication; and M3 IM clerkship OSCE total percentages. Data were organized by class, M3 IM clerkship OSCE performance, and timing of the clerkship. Microsoft Excel and SPSS were used for data organization and analysis. Results Of the 245 records, 229 (93.5%) had data points for all metrics of interest. Significant differences between the classes of 2013 and 2014 existed for average M2 spring total, M2 spring communication, and M3 IM clerkship OSCEs. Retrospectively, there were no differences in M2 OSCE performances based on how students scored on the M3 IM clerkship OSCE. M3 IM clerkship OSCE performance improved for those students who completed the clerkship last in the academic year. Conclusions There were inconsistencies in OSCE performances between the classes of 2013 and 2014, but more information is needed to determine if this is because of

  11. Hypothetical Preclinical Alzheimer Disease Groups and Longitudinal Cognitive Change.

    PubMed

    Soldan, Anja; Pettigrew, Corinne; Cai, Qing; Wang, Mei-Cheng; Moghekar, Abhay R; O'Brien, Richard J; Selnes, Ola A; Albert, Marilyn S

    2016-06-01

    Clinical trials testing treatments for Alzheimer disease (AD) are increasingly focused on cognitively normal individuals in the preclinical phase of the disease. To optimize observing a treatment effect, such trials need to enroll cognitively normal individuals likely to show cognitive decline over the duration of the trial. To identify which group of cognitively normal individuals shows the greatest cognitive decline over time based on their cerebrospinal fluid biomarker profile. In this cohort study, cognitively normal participants were classified into 1 of the following 4 hypothetical preclinical AD groups using baseline cerebrospinal fluid levels of Aβ and tau or Aβ and phosphorylated tau (p-tau): stage 0 (high Aβ and low tau), stage 1 (low Aβ and low tau), stage 2 (low Aβ and high tau), and suspected non-AD pathology (SNAP) (high Aβ and high tau). The data presented herein were collected between August 1995 and August 2014. An a priori cognitive composite score based on the following 4 tests previously shown to predict progression from normal cognition to symptom onset of mild cognitive impairment or dementia: Paired Associates immediate recall, Logical Memory delayed recall, Boston Naming, and Digit-Symbol Substitution. Linear mixed-effects models were used to compare the cognitive composite scores across the 4 groups over time, adjusting for baseline age, sex, education, and their interactions with time. Two hundred twenty-two cognitively normal participants were included in the analyses (mean follow-up, 11.0 years [range, 0-18.3 years] and mean baseline age, 56.9 years [range, 22.1-85.8 years]). Of these, 102 were stage 0, 46 were stage 1, 28 were stage 2, and 46 were SNAP. Individuals in stage 2 (low Aβ and high tau [or p-tau]) had lower baseline cognitive scores and a greater decline in the cognitive composite score relative to the other 3 groups (β ≤ -0.06 for all and P ≤ .001 for the rate of decline for all). Individuals in stage 0

  12. Safety Handbook.

    ERIC Educational Resources Information Center

    Montgomery County Public Schools, Rockville, MD.

    Safety policies, procedures, and related information are presented in this manual to assist school personnel in a continuing program of accident prevention. Chapter 1 discusses safety education and accident prevention in general. Chapter 2 covers traffic regulations relating to school safety patrols, school bus transportation, bicycles, and…

  13. Fire safety

    Treesearch

    Robert H. White; Mark A. Dietenberger

    1999-01-01

    Fire safety is an important concern in all types of construction. The high level of national concern for fire safety is reflected in limitations and design requirements in building codes. These code requirements are discussed in the context of fire safety design and evaluation in the initial section of this chapter. Since basic data on fire behavior of wood products...

  14. From research to phase III: preclinical, industrial and clinical development of the Sanofi Pasteur tetravalent dengue vaccine.

    PubMed

    Guy, Bruno; Barrere, Beatrice; Malinowski, Claire; Saville, Melanie; Teyssou, Remy; Lang, Jean

    2011-09-23

    Dengue vaccine development has reached a major milestone with the initiation, in 2010, of the first phase III clinical trial to investigate the Sanofi Pasteur CYD tetravalent dengue vaccine (TDV). The CYD TDV candidate is composed of four recombinant, live, attenuated vaccines (CYD-1-4) based on a yellow fever vaccine 17D (YFV 17D) backbone, each expressing the pre-membrane and envelope genes of one of the four dengue virus serotypes. The vaccine is genetically and phenotypically stable, non-hepatotropic, less neurovirulent than YFV 17D, and does not infect mosquitoes by the oral route. In vitro and in vivo preclinical studies showed that CYD TDV induces controlled stimulation of human dendritic cells, and significant immune responses in monkeys. Scale up and industrialization are being conducted in parallel with preclinical and clinical development to fulfill the needs of phase II/III trials, and to anticipate and facilitate supply and access to vaccine in the countries where the dengue disease burden makes it an urgent public health priority. The vaccine has now been administered to more than 6000 children and adults from dengue endemic and non-endemic areas and no safety concerns have arisen in any of the completed or ongoing trials. A three-dose vaccination regimen induces an immune response against all four serotypes in the large majority of vaccinees. Preexisting flavivirus immunity favors quicker and higher immune responses to CYD TDV, without adversely effecting clinical safety or increasing vaccine viremia. The observed level and nature of the cellular immune responses in humans are consistent with the good safety and immunogenicity profile of the vaccine. Preliminary results of an ongoing, proof-of-concept efficacy and large scale safety study in Thai children are expected by the end of 2012. Here we discuss the different steps and challenges of developing CYD TDV, from research to industrialization, and summarize some of the challenges to the successful

  15. Long term exposure to L-arginine accelerates endothelial cell senescence through arginase-II and S6K1 signaling

    PubMed Central

    Xiong, Yuyani; Fru, Michael Forbiteh; Yu, Yi; Montani, Jean-Pierre; Ming, Xiu-Fen; Yang, Zhihong

    2014-01-01

    L-arginine supplementation is proposed to improve health status or as adjunct therapy for diseases including cardiovascular diseases. However, controversial results and even detrimental effects of L-arginine supplementation are reported. We investigate potential mechanisms of L-arginine-induced detrimental effects on vascular endothelial cells. Human endothelial cells were exposed to a physiological (0.1 mmol/L) or pharmacological (0.5 mmol/L) concentration of L-arginine for 30 minutes (acute) or 7 days (chronic). The effects of L-arginine supplementation on endothelial senescence phenotype, i.e., levels of senescence-associated beta-galactosidase, expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1, eNOS-uncoupling, arginase-II expression/activity, and mTORC1-S6K1 activity were analyzed. While acute L-arginine treatment enhances endothelial NO production accompanied with superoxide production and activation of S6K1 but no up-regulation of arginase-II, chronic L-arginine supplementation causes endothelial senescence, up-regulation of the adhesion molecule expression, and eNOS-uncoupling (decreased NO and enhanced superoxide production), which are associated with S6K1 activation and up-regulation of arginase-II. Silencing either S6K1 or arginase-II inhibits up-regulation/activation of each other, prevents endothelial dysfunction, adhesion molecule expression, and senescence under the chronic L-arginine supplementation condition. These results demonstrate that S6K1 and arginase-II form a positive circuit mediating the detrimental effects of chronic L-arginine supplementation on endothelial cells. PMID:24860943

  16. Influence of supplementation with branched-chain amino acids in combination with resistance exercise on p70S6 kinase phosphorylation in resting and exercising human skeletal muscle.

    PubMed

    Apró, W; Blomstrand, E

    2010-11-01

    Skeletal muscle growth is thought to be regulated by the mammalian target of rapamycin (mTOR) pathway, which can be activated by resistance exercise and branched-chain amino acids (BCAA). The major aim of the present study was to distinguish between the influence of resistance exercise and BCAA on key enzymes considered to be involved in the regulation of protein synthesis, including p70(S6) kinase (p70(S6k)). Nine healthy subjects (four men and five women) performed unilateral resistance exercise on two occasions separated by 1 month. Subjects were randomly supplied either a mixture of BCAA or flavoured water. Muscle biopsies were taken from both resting and exercising muscle before, after and 1 h after exercise. Phosphorylation of Akt was unaltered by either resistance exercise and/or BCAA supplementation whereas mTOR phosphorylation was enhanced (P<0.05) to a similar extent in both exercising and resting muscle following exercise in the absence (70-90%) and presence of BCAA supplementation (80-130%). Phosphorylation of p70(S6k) was unaffected by resistance exercise alone; however, BCAA intake increased (P<0.05) this phosphorylation in both legs following exercise. In resting muscle, a 5- and 16-fold increase in p70(S6k) was observed immediately after and 1 h after exercise, respectively, as compared to 11- and 30-fold increases in the exercising muscle. Phosphorylation of eukaryotic elongation factor 2 was attenuated 1 h after exercise (P<0.05) in both resting (10-40%) and exercising muscle (30-50%) under both conditions. The present findings indicate that resistance exercise and BCAA exert both separate and combined effects on the p70(S6k) phosphorylation in an Akt-independent manner. © 2010 The Authors. Journal compilation © 2010 Scandinavian Physiological Society.

  17. IL-3 Maintains Activation of the p90S6K/RPS6 Pathway and Increases Translation in Human Eosinophils.

    PubMed

    Esnault, Stephane; Kelly, Elizabeth A B; Shen, Zhong-Jian; Johansson, Mats W; Malter, James S; Jarjour, Nizar N

    2015-09-15

    IL-5 is a major therapeutic target to reduce eosinophilia. However, all of the eosinophil-activating cytokines, such as IL-5, IL-3, and GM-CSF, are typically present in atopic diseases, including allergic asthma. As a result of the functional redundancy of these three cytokines on eosinophils and the loss of IL-5R on airway eosinophils, it is important to take IL-3 and GM-CSF into account to efficiently reduce tissue eosinophil functions. Moreover, these three cytokines signal through a common β-chain receptor but yet differentially affect protein production in eosinophils. Notably, the increased ability of IL-3 to induce the production of proteins, such as semaphorin-7A, without affecting mRNA levels suggests a unique influence of IL-3 on translation. The purpose of this study was to identify the mechanisms by which IL-3 distinctively affects eosinophil function compared with IL-5 and GM-CSF, with a focus on protein translation. Peripheral blood eosinophils were used to study intracellular signaling and protein translation in cells activated with IL-3, GM-CSF, or IL-5. We establish that, unlike GM-CSF or IL-5, IL-3 triggers prolonged signaling through activation of ribosomal protein S6 (RPS6) and the upstream kinase 90-kDa ribosomal S6 kinase (p90S6K). Blockade of p90S6K activation inhibited phosphorylation of RPS6 and IL-3-enhanced semaphorin-7A translation. Furthermore, in an allergen-challenged environment, in vivo phosphorylation of RPS6 and p90S6K was enhanced in human airway compared with circulating eosinophils. Our findings provide new insights into the mechanisms underlying differential activation of eosinophils by IL-3, GM-CSF, and IL-5. These observations identify IL-3 and its downstream intracellular signals as novel targets that should be considered to modulate eosinophil functions. Copyright © 2015 by The American Association of Immunologists, Inc.

  18. Inhibition of p70S6K1 Activation by Pdcd4 Overcomes the Resistance to an IGF-1R/IR Inhibitor in Colon Carcinoma Cells.

    PubMed

    Zhang, Yan; Wang, Qing; Chen, Li; Yang, Hsin-Sheng

    2015-03-01

    Agents targeting insulin-like growth factor 1 receptor (IGF-1R) are being actively examined in clinical trials. Although there has been some initial success of single-agent targeting IGF-1R, attempts in later studies failed because of resistance. This study aimed to understand the effects of programmed cell death 4 (Pdcd4) on the chemosensitivity of the IGF-1R inhibitor OSI-906 in colorectal cancer cells and the mechanism underlying this impact. Using OSI-906-resistant and -sensitive colorectal cancer cells, we found that the Pdcd4 level directly correlates with cell chemosensitivity to OSI-906. In addition, tumors derived from Pdcd4 knockdown cells resist the growth inhibitory effect of OSI-906 in a colorectal cancer xenograft mouse model. Moreover, Pdcd4 enhances the antiproliferative effect of OSI-906 in resistant cells through suppression of p70S6K1 activation. Knockdown of p70S6K1, but not p70S6K2, significantly increases the chemosensitivity of OSI-906 in cultured colorectal cancer cells. Furthermore, the combination of OSI-906 and PF-4708671, a p70S6K1 inhibitor, efficiently suppresses the growth of OSI-906-resistant colon tumor cells in vitro and in vivo. Taken together, activation of p70S6K1 that is inhibited by Pdcd4 is essential for resistance to the IGF-1R inhibitor in colon tumor cells, and the combinational treatment of OSI-906 and PF-4708671 results in enhanced antiproliferation effects in colorectal cancer cells in vitro and in vivo, providing a novel venue to overcome the resistance to the IGF-1R inhibitor in treating colorectal cancer. ©2015 American Association for Cancer Research.

  19. Inhibition of p70S6K1 activation by Pdcd4 overcomes the resistance to an IGF-1R/IR inhibitor in colon carcinoma cells

    PubMed Central

    Zhang, Yan; Wang, Qing; Chen, Li; Yang, Hsin-Sheng

    2015-01-01

    Agents targeting insulin-like growth factor 1 receptor (IGF-1R) are being actively examined in clinical trials. Although there has been some initial success of single agent targeting IGF-1R, attempts in later studies failed due to resistance. This study aimed to understand the effects of programmed cell death 4 (Pdcd4) on the chemosensitivity of the IGF-1R inhibitor, OSI-906, in colorectal cancer (CRC) cells and the mechanism underlying this impact. Using OSI-906 resistant and sensitive CRC cells, we found that the Pdcd4 level directly correlates with cell chemosensitivity to OSI-906. In addition, tumors derived from Pdcd4 knockdown cells resist the growth inhibitory effect of OSI-906 in a CRC xenograft mouse model. Moreover, Pdcd4 enhances the antiproliferative effect of OSI-906 in resistant cells through suppression of p70S6K1 activation. Knockdown of p70S6K1, but not p70S6K2, significantly increases the chemosensitivity of OSI-906 in cultured CRC cells. Furthermore, the combination of OSI-906 and PF4708671, a p70S6K1 inhibitor, efficiently suppresses the growth of OSI-906 resistant colon tumor cells in vitro and in vivo. Taken together, activation of p70S6K1 that is inhibited by Pdcd4 is essential for resistance to IGF-1R inhibitor in colon tumor cells, and the combinational treatment of OSI-906 and PF-4708671 results in enhanced antiproliferation effects in CRC cells in vitro and in vivo, providing a novel venue to overcome the resistance to IGF-1R inhibitor in treating colorectal cancer. PMID:25573956

  20. Preclinical evaluation of a novel abluminal surface coated sirolimus eluting stent with biodegradable polymer matrix

    PubMed Central

    Doshi, Manish; Galloni, Marco; Vignolini, Christina; Vyas, Ashwin; Chevli, Bhavesh; Sheiban, Imad

    2015-01-01

    Background Second generation of drug eluting stents (DES) has attempted to improve safety using abluminal sirolimus drug delivery with biodegradable polymers matrix. The present preclinical study was designed to investigate the safety and efficacy profile of Abluminus™ stents (SES). This is a new coronary stent with sirolimus and biodegradable polymer matrix coated on abluminal stent and balloon surface. Methods SES were compared with two controls: bare metal stent (BMS) and BMS + polymer coated stents (PC). All devices (40 stents) were implanted in porcine coronary arteries with primary endpoint of endothelialization at 7 days and subsequent histological and morphometric evaluations at 7, 30 and 90 days. Results Early endothelialization at seven days was complete in all stents. Histology at 30 days revealed minimum inflammation in all groups and increased at 90 days in PC group while it was absent at 180 days. Thirty day morphometry showed significantly reduction of neointimal area in Abluminus™ (SES 0.96±0.48 mm2; BMS 1.83±0.34 mm2; PC 1.76±0.55 mm2; P<0.05); after 90 days neointimal area was 1.10±0.54 mm2 for SES; 1.92±0.36 mm2 for BMS; and 1.94±0.48 mm2 for PC; P<0.05). Neointimal thickness at 30 and 90 days respectively was 0.15±0.07 and 0.18±0.10 mm for SES, 0.57±0.08 and 0.61±0.09 mm for BMS and 0.52±0.09 and 0.59±0.08 mm, P<0.001 for PC group. Conclusions The most significant experimental evidence appears to be earlier endothelialization at 7 days for SES which led to safety of the device. Efficacy of the device was also observed by a reduced neointimal thickness and minimized inflammatory score at all follow-ups. Termination of antiplatelet at 30 days has not shown any further complications. Polymer thickness was almost in negligible amount at 180 days with no inflammation. PMID:26331109

  1. Restoflex--a revolutionary change in preclinical practice for restorative dentistry and endodontics.

    PubMed

    Jain, Shweta; Khaiser, Imran M; Thakur, Sophia; Jain, Shikha

    2014-05-01

    Preclinical exercises are very important for the dental students in order to master various dental techniques. The objective of this article is to introduce a new preclinical working model named Restoflex. It is especially designed for the students to carry out various restorative and endodontic procedures in an environment that closely simulate clinical situations. This will help them to provide a smooth transition from preclinical environment to the clinical one. It would also mean an increased confidence level and the efficiency with which the students would deal with their cases.

  2. Preclinical activity of melflufen (J1) in ovarian cancer

    PubMed Central

    Viktorsson, Kristina; Velander, Ebba; Nygren, Peter; Uustalu, Maria; Juntti, Therese; Lewensohn, Rolf; Larsson, Rolf; Spira, Jack; De Vlieghere, Elly; Ceelen, Wim P.; Gullbo, Joachim

    2016-01-01

    Ovarian cancer carries a significant mortality. Since symptoms tend to be minimal, the disease is often diagnosed when peritoneal metastases are already present. The standard of care in advanced ovarian cancer consists of platinum-based chemotherapy combined with cytoreductive surgery. Unfortunately, even after optimal cytoreduction and adjuvant chemotherapy, most patients with stage III disease will develop a recurrence. Intraperitoneal administration of chemotherapy is an alternative treatment for patients with localized disease. The pharmacological and physiochemical properties of melflufen, a peptidase potentiated alkylator, raised the hypothesis that this drug could be useful in ovarian cancer and particularily against peritoneal carcinomatosis. In this study the preclinical effects of melflufen were investigated in different ovarian cancer models. Melflufen was active against ovarian cancer cell lines, primary cultures of patient-derived ovarian cancer cells, and inhibited the growth of subcutaneous A2780 ovarian cancer xenografts alone and when combined with gemcitabine or liposomal doxorubicin when administered intravenously. In addition, an intra- and subperitoneal xenograft model showed activity of intraperitoneal administered melflufen for peritoneal carcinomatosis, with minimal side effects and modest systemic exposure. In conclusion, results from this study support further investigations of melflufen for the treatment of peritoneal carcinomatosis from ovarian cancer, both for intravenous and intraperitoneal administration. PMID:27528037

  3. Recent Advances in Preclinical Developments Using Adenovirus Hybrid Vectors.

    PubMed

    Ehrke-Schulz, Eric; Zhang, Wenli; Gao, Jian; Ehrhardt, Anja

    2017-10-01

    Adenovirus (Ad)-based vectors are efficient gene-transfer vehicles to deliver foreign DNA into living organisms, offering large cargo capacity and low immunogenicity and genotoxicity. As Ad shows low integration rates of their genomes into host chromosomes, vector-derived gene expression decreases due to continuous cell cycling in regenerating tissues and dividing cell populations. To overcome this hurdle, adenoviral delivery can be combined with mechanisms leading to maintenance of therapeutic DNA and long-term effects of the desired treatment. Several hybrid Ad vectors (AdV) exploiting various strategies for long-term treatment have been developed and characterized. This review summarizes recent developments of preclinical approaches using hybrid AdVs utilizing either the Sleeping Beauty transposase system for somatic integration into host chromosomes or designer nucleases, including transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein-9 nuclease for permanent gene editing. Further options on how to optimize these vectors further are discussed, which may lead to future clinical applications of these versatile gene-therapy tools.

  4. Alpha-theta border EEG abnormalities in preclinical Huntington's disease.

    PubMed

    Ponomareva, Natalya; Klyushnikov, Sergey; Abramycheva, Natalya; Malina, Daria; Scheglova, Nadejda; Fokin, Vitaly; Ivanova-Smolenskaia, Irina; Illarioshkin, Sergey

    2014-09-15

    Brain dysfunction precedes clinical manifestation of Huntington's disease (HD) by decades. This study was aimed to determine whether resting EEG is altered in preclinical HD mutations carriers (pre-HD). We examined relative power of broad traditional EEG bands as well as 1-Hz sub-bands of theta and alpha from the resting-state EEG of 29 pre-HD individuals and of 29 age-matched normal controls. The relative power of the narrow sub-band in the border of theta-alpha (7-8 Hz) was significantly reduced in pre-HD subjects as compared to normal controls, while the alterations in relative power of the broad frequency bands were not significant. In pre-HD subjects, the number of CAG repeats in the huntingtin (HTT) gene as well as the disease burden score (DBS) showed a positive correlation with relative power of the delta and theta frequency bands and their sub-bands and a negative correlation with alpha band relative power and the differences of relative power of the 7-8 Hz and 4-5 Hz frequency sub-bands. The obtained results suggest that EEG alterations in pre-HD individuals may be related to the course of the pathological process and to HD endophenotype. Analysis of the narrow EEG bands was found to be more useful for assessing EEG alterations in pre-HD individuals than a more traditional approach using broad bandwidths. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Image-based informatics for Preclinical Biomedical Research

    SciTech Connect

    Tobin Jr, Kenneth William; Aykac, Deniz; Price, Jeffery R

    2006-01-01

    In 2006, the New England Journal of Medicine selected medical imaging as one of the eleven most important innovations of the past 1,000 years, primarily due to its ability to allow physicians and researchers to visualize the very nature of disease. As a result of the broad-based adoption of micro imaging technologies, preclinical researchers today are generating terabytes of image data from both anatomic and functional imaging modes. In this paper we describe our early research to apply content-based image retrieval to index and manage large image libraries generated in the study of amyloid disease in mice. Amyloidosis is associatedmore » with diseases such as Alzheimer's, type 2 diabetes, and myeloma. In particular, we will focus on results to date in the area of small animal organ segmentation and description for CT, SPECT, and PET modes and present a small set of preliminary retrieval results for a specific disease state in kidney CT cross-sections.« less

  6. Image-based Informatics for Preclinical Biomedical Research

    SciTech Connect

    Tobin Jr, Kenneth William; Aykac, Deniz; Muthusamy Govindasamy, Vijaya Priya

    2006-01-01

    In 2006, the New England Journal of Medicine selected medical imaging as one of the eleven most important innovations of the past 1,000 years, primarily due to its ability to allow physicians and researchers to visualize the very nature of disease. As a result of the broad-based adoption of micro imaging technologies, preclinical researchers today are generating terabytes of image data from both anatomic and functional imaging modes. In this paper we describe our early research to apply content-based image retrieval to index and manage large image libraries generated in the study of amyloid disease in mice. Amyloidosis is associatedmore » with diseases such as Alzheimer's, type 2 diabetes, chronic inflammation and myeloma. In particular, we will focus on results to date in the area of small animal organ segmentation and description for CT, SPECT, and PET modes and present a small set of preliminary retrieval results for a specific disease state in kidney CT crosssections.« less

  7. Preclinical studies for induced pluripotent stem cell-based therapeutics.

    PubMed

    Harding, John; Mirochnitchenko, Oleg

    2014-02-21

    Induced pluripotent stem cells (iPSCs) and their differentiated derivatives can potentially be applied to cell-based therapy for human diseases. The properties of iPSCs are being studied intensively both to understand the basic biology of pluripotency and cellular differentiation and to solve problems associated with therapeutic applications. Examples of specific preclinical applications summarized briefly in this minireview include the use of iPSCs to treat diseases of the liver, nervous system, eye, and heart and metabolic conditions such as diabetes. Early stage studies illustrate the potential of iPSC-derived cells and have identified several challenges that must be addressed before moving to clinical trials. These include rigorous quality control and efficient production of required cell populations, improvement of cell survival and engraftment, and development of technologies to monitor transplanted cell behavior for extended periods of time. Problems related to immune rejection, genetic instability, and tumorigenicity must be solved. Testing the efficacy of iPSC-based therapies requires further improvement of animal models precisely recapitulating human disease conditions.

  8. Can cancer researchers accurately judge whether preclinical reports will reproduce?

    PubMed Central

    Mandel, David R.; Kimmelman, Jonathan

    2017-01-01

    There is vigorous debate about the reproducibility of research findings in cancer biology. Whether scientists can accurately assess which experiments will reproduce original findings is important to determining the pace at which science self-corrects. We collected forecasts from basic and preclinical cancer researchers on the first 6 replication studies conducted by the Reproducibility Project: Cancer Biology (RP:CB) to assess the accuracy of expert judgments on specific replication outcomes. On average, researchers forecasted a 75% probability of replicating the statistical significance and a 50% probability of replicating the effect size, yet none of these studies successfully replicated on either criterion (for the 5 studies with results reported). Accuracy was related to expertise: experts with higher h-indices were more accurate, whereas experts with more topic-specific expertise were less accurate. Our findings suggest that experts, especially those with specialized knowledge, were overconfident about the RP:CB replicating individual experiments within published reports; researcher optimism likely reflects a combination of overestimating the validity of original studies and underestimating the difficulties of repeating their methodologies. PMID:28662052

  9. Robotic Anterior and Midline Skull Base Surgery: Preclinical Investigations

    SciTech Connect

    O'Malley, Bert W.; Weinstein, Gregory S.

    Purpose: To develop a minimally invasive surgical technique to access the midline and anterior skull base using the optical and technical advantages of robotic surgical instrumentation. Methods and Materials: Ten experimental procedures focusing on approaches to the nasopharynx, clivus, sphenoid, pituitary sella, and suprasellar regions were performed on one cadaver and one live mongrel dog. Both the cadaver and canine procedures were performed in an approved training facility using the da Vinci Surgical Robot. For the canine experiments, a transoral robotic surgery (TORS) approach was used, and for the cadaver a newly developed combined cervical-transoral robotic surgery (C-TORS) approach wasmore » investigated and compared with standard TORS. The ability to access and dissect tissues within the various areas of the midline and anterior skull base were evaluated, and techniques to enhance visualization and instrumentation were developed. Results: Standard TORS approaches did not provide adequate access to the midline and anterior skull base; however, the newly developed C-TORS approach was successful in providing the surgical access to these regions of the skull base. Conclusion: Robotic surgery is an exciting minimally invasive approach to the skull base that warrants continued preclinical investigation and development.« less

  10. A New Preclinical Paradigm for Testing Anti-Aging Therapeutics.

    PubMed

    Ladiges, Warren; Snyder, Jessica M; Wilkinson, Erby; Imai, Denise M; Snider, Tim; Ge, Xuan; Ciol, Marcia; Pettan-Brewer, Christina; Pillai, Smitha P S; Morton, John; Quarles, Ellen; Rabinovitch, Peter; Niedernhofer, Laura; Liggitt, Denny

    2017-06-01

    Testing drugs for anti-aging effects has historically been conducted in mouse life-span studies, but are costly and time consuming, and more importantly, difficult to recapitulate in humans. In addition, life-span studies in mice are not well suited to testing drug combinations that target multiple factors involved in aging. Additional paradigms for testing therapeutics aimed at slowing aging are needed. A new paradigm, designated as the Geropathology Grading Platform (GGP), is based on a standardized set of guidelines developed to detect the presence or absence of low-impact histopathological lesions and to determine the level of severity of high-impact lesions in organs from aged mice. The GGP generates a numerical score for each age-related lesion in an organ, summed for total lesions, and averaged over multiple mice to obtain a composite lesion score (CLS). Preliminary studies show that the platform generates CLSs that increase with the age of mice in an organ-dependent manner. The CLSs are sensitive enough to detect changes elicited by interventions that extend mouse life span, and thus help validate the GGP as a novel tool to measure biological aging. While currently optimized for mice, the GGP could be adapted to any preclinical animal model. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Magnetic Fluid Hyperthermia for Bladder Cancer: A Preclinical Dosimetry Study

    PubMed Central

    Oliveira, Tiago R.; Stauffer, Paul R.; Lee, Chen-Ting; Landon, Chelsea D.; Etienne, Wiguins; Ashcraft, Kathleen A.; McNerny, Katie L.; Mashal, Alireza; Nouls, John; Maccarini, Paolo F.; Beyer, Wayne F.; Inman, Brant; Dewhirst, Mark W.

    2014-01-01

    Purpose This paper describes a preclinical investigation of the feasibility of thermotherapy treatment of bladder cancer with Magnetic Fluid Hyperthermia (MFH), performed by analyzing the thermal dosimetry of nanoparticle heating in a rat bladder model. Materials and Methods The bladders of twenty-five female rats were instilled with magnetite-based nanoparticles, and hyperthermia was induced using a novel small animal magnetic field applicator (Actium Biosystems, Boulder, CO). We aimed to increase the bladder lumen temperature to 42°C in <10 min and maintain that temperature for 60 min. Temperatures were measured within the bladder lumen and throughout the rat with seven fiberoptic probes (OpSens Technologies, Quebec, Canada). An MRI analysis was used to confirm the effectiveness of the catheterization method to deliver and maintain various nanoparticle volumes within the bladder. Thermal dosimetry measurements recorded the temperature rise of rat tissues for a variety of nanoparticle exposure conditions. Results Thermal dosimetry data demonstrated our ability to raise and control the temperature of rat bladder lumen ≥1°C/min to a steady-state of 42°C with minimal heating of surrounding normal tissues. MRI scans confirmed the homogenous nanoparticle distribution throughout the bladder. Conclusion These data demonstrate that our MFH system with magnetite-based nanoparticles provide well-localized heating of rat bladder lumen with effective control of temperature in the bladder and minimal heating of surrounding tissues. PMID:24050253

  12. Pica in Rats as a Preclinical Model of Emesis.

    PubMed

    Davis, T Gregg

    2016-10-03

    The ability to assess the potential for gastrointestinal adverse events in a preclinical setting is a challenge in the development of new drugs, as the vast majority of in vivo research is conducted in rodent species lacking a vomiting reflex. The use of higher species capable of emesis is often limited by cost, technical experience, and relevant efficacy models to define a therapeutic index. Additionally, investigators should be mindful of ethical considerations when using more sentient species when an alternative in lower species is available. This unit describes the use of pica behavior in rodents as an alternative for evaluating emetic potential in vivo. After an acclimation period, the incidence of rats engaging in pica following the administration of a test article can be used to generate a dose-response curve of the pica behavior. When linked with an appropriate efficacy model, this allows compounds to be ranked based on therapeutic index. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  13. 'Muscle-sparing' statins: preclinical profiles and future clinical use.

    PubMed

    Pfefferkorn, Jeffrey A

    2009-03-01

    Coronary heart disease (CHD) is a leading cause of death in the US, and hypercholesterolemia is a key risk factor for this disease. The current standard of care for treating hypercholesterolemia is the use of HMG-CoA reductase inhibitors, also known as statins, which block the rate-limiting step of cholesterol biosynthesis. In widespread clinical use, statins have proven safe and effective for both primary prevention of CHD and secondary prevention of coronary events. Results from several recent clinical trials have demonstrated that increasingly aggressive cholesterol-lowering therapy might offer additional protection against CHD compared with less aggressive treatment standards. While higher doses of current statin therapies are capable of achieving these more aggressive treatment goals, in certain cases statin-induced myalgia, the muscle pain or weakness that sometimes accompanies high-dose statin therapy, limits patient compliance with a treatment regimen. To address this limitation, efforts have been undertaken to develop highly hepatoselective statins that are capable of delivering best-in-class efficacy with minimized risk of dose-limiting myalgia. In this review, the preclinical and early clinical data for these next generation statins are discussed.

  14. Preclinical Development of New Therapy for Glycogen Storage Diseases

    PubMed Central

    Sun, Baodong; Brooks, Elizabeth D.; Koeberl, Dwight D.

    2015-01-01

    Glycogen storage disease (GSD) consists of more than 10 discrete conditions for which the biochemical and genetic bases have been determined, and new therapies have been under development for several of these conditions. Gene therapy research has generated proof-of-concept for GSD types I (von Gierke disease) and II (Pompe disease). Key features of these gene therapy strategies include the choice of vector and regulatory cassette, and recently adeno-associated virus (AAV) vectors containing tissue-specific promoters have achieved a high degree of efficacy. Efficacy of gene therapy for Pompe disease depend upon the induction of immune tolerance to the therapeutic enzyme. Efficacy of von Gierke disease is transient, waning gradually over the months following vector administration. Small molecule therapies have been evaluated with the goal of improving standard of care therapy or ameliorating the cellular abnormalities associated with specific GSDs. The receptor-mediated uptake of the therapeutic enzyme in Pompe disease was enhanced by administration of β2 agonists. Rapamycin reduced the liver fibrosis observed in GSD III. Further development of gene therapy could provide curative therapy for patients with GSD, if efficacy from preclinical research is observed in future clinical trials and these treatments become clinically available. PMID:26122079

  15. Neurotoxicity in Preclinical Models of Occupational Exposure to Organophosphorus Compounds

    PubMed Central

    Voorhees, Jaymie R.; Rohlman, Diane S.; Lein, Pamela J.; Pieper, Andrew A.

    2017-01-01

    Organophosphorus (OPs) compounds are widely used as insecticides, plasticizers, and fuel additives. These compounds potently inhibit acetylcholinesterase (AChE), the enzyme that inactivates acetylcholine at neuronal synapses, and acute exposure to high OP levels can cause cholinergic crisis in humans and animals. Evidence further suggests that repeated exposure to lower OP levels insufficient to cause cholinergic crisis, frequently encountered in the occupational setting, also pose serious risks to people. For example, multiple epidemiological studies have identified associations between occupational OP exposure and neurodegenerative disease, psychiatric illness, and sensorimotor deficits. Rigorous scientific investigation of the basic science mechanisms underlying these epidemiological findings requires valid preclinical models in which tightly-regulated exposure paradigms can be correlated with neurotoxicity. Here, we review the experimental models of occupational OP exposure currently used in the field. We found that animal studies simulating occupational OP exposures do indeed show evidence of neurotoxicity, and that utilization of these models is helping illuminate the mechanisms underlying OP-induced neurological sequelae. Still, further work is necessary to evaluate exposure levels, protection methods, and treatment strategies, which taken together could serve to modify guidelines for improving workplace conditions globally. PMID:28149268

  16. Validation of a Preclinical Drug Screening Platform for Pharmacoresistant Epilepsy.

    PubMed

    Barker-Haliski, Melissa L; Johnson, Kristina; Billingsley, Peggy; Huff, Jennifer; Handy, Laura J; Khaleel, Rizvana; Lu, Zhenmei; Mau, Matthew J; Pruess, Timothy H; Rueda, Carlos; Saunders, Gerald; Underwood, Tristan K; Vanegas, Fabiola; Smith, Misty D; West, Peter J; Wilcox, Karen S

    2017-07-01

    The successful identification of promising investigational therapies for the treatment of epilepsy can be credited to the use of numerous animal models of seizure and epilepsy for over 80 years. In this time, the maximal electroshock test in mice and rats, the subcutaneous pentylenetetrazol test in mice and rats, and more recently the 6 Hz assay in mice, have been utilized as primary models of electrically or chemically-evoked seizures in neurologically intact rodents. In addition, rodent kindling models, in which chronic network hyperexcitability has developed, have been used to identify new agents. It is clear that this traditional screening approach has greatly expanded the number of marketed drugs available to manage the symptomatic seizures associated with epilepsy. In spite of the numerous antiseizure drugs (ASDs) on the market today, the fact remains that nearly 30% of patients are resistant to these currently available medications. To address this unmet medical need, the National Institute of Neurological Disorders and Stroke (NINDS) Epilepsy Therapy Screening Program (ETSP) revised its approach to the early evaluation of investigational agents for the treatment of epilepsy in 2015 to include a focus on preclinical approaches to model pharmacoresistant seizures. This present report highlights the in vivo and in vitro findings associated with the initial pharmacological validation of this testing approach using a number of mechanistically diverse, commercially available antiseizure drugs, as well as several probe compounds that are of potential mechanistic interest to the clinical management of epilepsy.

  17. Neurotoxicity in Preclinical Models of Occupational Exposure to Organophosphorus Compounds.

    PubMed

    Voorhees, Jaymie R; Rohlman, Diane S; Lein, Pamela J; Pieper, Andrew A

    2016-01-01

    Organophosphorus (OPs) compounds are widely used as insecticides, plasticizers, and fuel additives. These compounds potently inhibit acetylcholinesterase (AChE), the enzyme that inactivates acetylcholine at neuronal synapses, and acute exposure to high OP levels can cause cholinergic crisis in humans and animals. Evidence further suggests that repeated exposure to lower OP levels insufficient to cause cholinergic crisis, frequently encountered in the occupational setting, also pose serious risks to people. For example, multiple epidemiological studies have identified associations between occupational OP exposure and neurodegenerative disease, psychiatric illness, and sensorimotor deficits. Rigorous scientific investigation of the basic science mechanisms underlying these epidemiological findings requires valid preclinical models in which tightly-regulated exposure paradigms can be correlated with neurotoxicity. Here, we review the experimental models of occupational OP exposure currently used in the field. We found that animal studies simulating occupational OP exposures do indeed show evidence of neurotoxicity, and that utilization of these models is helping illuminate the mechanisms underlying OP-induced neurological sequelae. Still, further work is necessary to evaluate exposure levels, protection methods, and treatment strategies, which taken together could serve to modify guidelines for improving workplace conditions globally.

  18. [Mechanism of action and preclinical development of afatinib].

    PubMed

    Diz Taín, Pilar; González, Ana López; García-Palomo, Andrés

    2016-04-01

    Afatinib, together with gefitinib and erlotinib, is approved for first-line treatment of advanced non-small cell lung cancer (NSCLC) with activating mutations of the epidermal growth factor receptor (EGFR). This is an irreversible inhibitor of the ErbB family, acting on EGFR (HER1, ErbB1), ErbB2 (HER2) and ErbB4 (HER4). Covalent attachment to cysteine residues in the catalytic domain of EGFR, HER2 and ErbB4 inhibits the tyrosine kinase activity (TKIs) of these receptors, decreasing auto- and transphosphorylation between ErbB dimers, and thus blocking the activity of downstream signalling pathways related to growth and apoptosis suppression. In preclinical models, this has resulted in a reduction in tumour size. Furthermore, due to its mechanism of action, afatinib may be more potent than the first-generation EGFR TKIs (gefitinib and erlotinib) and may even be able to overcome acquired resistance to such treatments. Finally, because of the demonstrated synergism with other chemotherapeutic and target agents, it could be interesting to enhance its clinical development in combination with other drugs. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  19. BEHAVIORAL OUTCOMES OF MONOAMINE OXIDASE DEFICIENCY: PRECLINICAL AND CLINICAL EVIDENCE

    PubMed Central

    Bortolato, Marco; Shih, Jean C.

    2012-01-01

    Monoamine oxidase (MAO) isoenzymes A and B are mitochondrial-bound proteins, catalyzing the oxidative deamination of monoamine neurotransmitters as well as xenobiotic amines. Although they derive from a common ancestral progenitor gene, are located at X-chromosome and display 70% structural identity, their substrate preference, regional distribution, and physiological role are divergent. In fact, while MAO-A has high affinity for serotonin and norepinephrine, MAO-B primarily serves the catabolism of 2-phenylethylamine (PEA) and contributes to the degradation of other trace amines and dopamine. Convergent lines of preclinical and clinical evidence indicate that variations in MAO enzymatic activity—due to either genetic or environmental factors—can exert a profound influence on behavioral regulation and play a role in the pathophysiology of a large spectrum of mental and neurodegenerative disorders, ranging from antisocial personality disorder to Parkinson’s disease. Over the past few years, numerous advances have been made in our understanding of the phenotypical variations associated with genetic polymorphisms and mutations of the genes encoding for both isoenzymes. In particular, novel findings on the phenotypes of MAO-deficient mice are highlighting novel potential implications of both isoenzymes in a broad spectrum of mental disorders, ranging from autism and anxiety to impulse-control disorders and ADHD. These studies will lay the foundation for future research on the neurobiological and neurochemical bases of these pathological conditions, as well as the role of gene × environment interactions in the vulnerability to several mental disorders. PMID:21971001

  20. Preclinical and Clinical Effects of Mistletoe against Breast Cancer

    PubMed Central

    Marvibaigi, Mohsen; Amini, Neda; Abdul Majid, Fadzilah Adibah; Jaganathan, Saravana Kumar

    2014-01-01

    Breast cancer is among the most frequent types of cancer in women worldwide. Current conventional treatment options are accompanied by side effects. Mistletoe is amongst the important herbal medicines traditionally used as complementary remedies. An increasing number of studies have reported anticancer activity of mistletoe extracts on breast cancer cells and animal models. Some recent evidence suggests that cytotoxic activity of mistletoe may be mediated through different mechanisms. These findings provide a good base for clinical trials. Various studies on mistletoe therapy for breast cancer patients revealed similar findings concerning possible benefits on survival time, health-related quality of life (HRQoL), remission rate, and alleviating adverse reactions to conventional therapy. This review provides an overview of the recent findings on preclinical experiments and clinical trials of mistletoe for its cytotoxic and antitumor activity and its effect on HRQoL in breast cancer patients. Moreover, studies investigating molecular and cellular mechanisms underlying antitumor activity of mistletoe are discussed in this paper. The analyzed trials provided evidence that there might be a combination of pharmacological and motivational aspects mediated by the mistletoe extract application which may contribute to the clinical benefit and positive outcome such as improved HRQoL and self-regulation in breast cancer patients. PMID:25136622

  1. Psychopharmacological neuroprotection in neurodegenerative disease: assessing the preclinical data.

    PubMed

    Lauterbach, Edward C; Victoroff, Jeff; Coburn, Kerry L; Shillcutt, Samuel D; Doonan, Suzanne M; Mendez, Mario F

    2010-01-01

    This manuscript reviews the preclinical in vitro, ex vivo, and nonhuman in vivo effects of psychopharmacological agents in clinical use on cell physiology with a view toward identifying agents with neuroprotective properties in neurodegenerative disease. These agents are routinely used in the symptomatic treatment of neurodegenerative disease. Each agent is reviewed in terms of its effects on pathogenic proteins, proteasomal function, mitochondrial viability, mitochondrial function and metabolism, mitochondrial permeability transition pore development, cellular viability, and apoptosis. Effects on the metabolism of the neurodegenerative disease pathogenic proteins alpha-synuclein, beta-amyloid, and tau, including tau phosphorylation, are particularly addressed, with application to Alzheimer's and Parkinson's diseases. Limitations of the current data are detailed and predictive criteria for translational clinical neuroprotection are proposed and discussed. Drugs that warrant further study for neuroprotection in neurodegenerative disease include pramipexole, thioridazine, risperidone, olanzapine, quetiapine, lithium, valproate, desipramine, maprotiline, fluoxetine, buspirone, clonazepam, diphenhydramine, and melatonin. Those with multiple neuroprotective mechanisms include pramipexole, thioridazine, olanzapine, quetiapine, lithium, valproate, desipramine, maprotiline, clonazepam, and melatonin. Those best viewed circumspectly in neurodegenerative disease until clinical disease course outcomes data become available, include several antipsychotics, lithium, oxcarbazepine, valproate, several tricyclic antidepressants, certain SSRIs, diazepam, and possibly diphenhydramine. A search for clinical studies of neuroprotection revealed only a single study demonstrating putatively positive results for ropinirole. An agenda for research on potentially neuroprotective agent is provided.

  2. Preclinical activity of melflufen (J1) in ovarian cancer.

    PubMed

    Carlier, Charlotte; Strese, Sara; Viktorsson, Kristina; Velander, Ebba; Nygren, Peter; Uustalu, Maria; Juntti, Therese; Lewensohn, Rolf; Larsson, Rolf; Spira, Jack; De Vlieghere, Elly; Ceelen, Wim P; Gullbo, Joachim

    2016-09-13

    Ovarian cancer carries a significant mortality. Since symptoms tend to be minimal, the disease is often diagnosed when peritoneal metastases are already present. The standard of care in advanced ovarian cancer consists of platinum-based chemotherapy combined with cytoreductive surgery. Unfortunately, even after optimal cytoreduction and adjuvant chemotherapy, most patients with stage III disease will develop a recurrence. Intraperitoneal administration of chemotherapy is an alternative treatment for patients with localized disease. The pharmacological and physiochemical properties of melflufen, a peptidase potentiated alkylator, raised the hypothesis that this drug could be useful in ovarian cancer and particularily against peritoneal carcinomatosis. In this study the preclinical effects of melflufen were investigated in different ovarian cancer models. Melflufen was active against ovarian cancer cell lines, primary cultures of patient-derived ovarian cancer cells, and inhibited the growth of subcutaneous A2780 ovarian cancer xenografts alone and when combined with gemcitabine or liposomal doxorubicin when administered intravenously. In addition, an intra- and subperitoneal xenograft model showed activity of intraperitoneal administered melflufen for peritoneal carcinomatosis, with minimal side effects and modest systemic exposure. In conclusion, results from this study support further investigations of melflufen for the treatment of peritoneal carcinomatosis from ovarian cancer, both for intravenous and intraperitoneal administration.

  3. DNA nanomaterials for preclinical imaging and drug delivery.

    PubMed

    Jiang, Dawei; England, Christopher G; Cai, Weibo

    2016-10-10

    Besides being the carrier of genetic information, DNA is also an excellent biological organizer to establish well-designed nanostructures in the fields of material engineering, nanotechnology, and biomedicine. DNA-based materials represent a diverse nanoscale system primarily due to their predictable base pairing and highly regulated conformations, which greatly facilitate the construction of DNA nanostructures with distinct shapes and sizes. Integrating the emerging advancements in bioconjugation techniques, DNA nanostructures can be readily functionalized with high precision for many purposes ranging from biosensors to imaging to drug delivery. Recent progress in the field of DNA nanotechnology has exhibited collective efforts to employ DNA nanostructures as smart imaging agents or delivery platforms within living organisms. Despite significant improvements in the development of DNA nanostructures, there is limited knowledge regarding the in vivo biological fate of these intriguing nanomaterials. In this review, we summarize the current strategies for designing and purifying highly-versatile DNA nanostructures for biological applications, including molecular imaging and drug delivery. Since DNA nanostructures may elicit an immune response in vivo, we also present a short discussion of their potential toxicities in biomedical applications. Lastly, we discuss future perspectives and potential challenges that may limit the effective preclinical and clinical employment of DNA nanostructures. Due to their unique properties, we predict that DNA nanomaterials will make excellent agents for effective diagnostic imaging and drug delivery, improving patient outcome in cancer and other related diseases in the near future. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Identification and preclinical testing of novel antiepileptic compounds.

    PubMed

    Meldrum, B S

    1997-01-01

    Procedures for identifying novel antiepileptic drugs (AEDs) are changing and need to change more. Widespread reliance on two primary screens has led to the identification of novel compounds that resemble either phenytoin (suppressing high-frequency repetitive firing in cultured neurons and prolonging inactivation of voltage-dependent sodium channels identified by the maximal electroshock test) or benzodiazepines (potentiating the inhibitory effect of gamma-aminobutyric acid (GABA), identified by the threshold pentylenetetrazol test). Advances in molecular neurobiology have identified specific molecular targets (subunits of ion channels, neurotransmitter receptors, and transporters) and have made them available in a form permitting high-throughput screening. AEDs can be designed to interact with specific sites on the target molecules. Alternatively, the molecular screens can be used to identify active components in natural products, including folk remedies. Preclinical in vivo screens can be improved by using animals with genetic or acquired epilepsies that have similar modifications in the properties of the target molecules as do human epilepsy syndromes. Future work is likely to define molecular targets for AEDs that will block or reverse chronic epileptogenesis.

  5. Improving treatment of neurodevelopmental disorders: recommendations based on preclinical studies.

    PubMed

    Homberg, Judith R; Kyzar, Evan J; Stewart, Adam Michael; Nguyen, Michael; Poudel, Manoj K; Echevarria, David J; Collier, Adam D; Gaikwad, Siddharth; Klimenko, Viktor M; Norton, William; Pittman, Julian; Nakamura, Shun; Koshiba, Mamiko; Yamanouchi, Hideo; Apryatin, Sergey A; Scattoni, Maria Luisa; Diamond, David M; Ullmann, Jeremy F P; Parker, Matthew O; Brown, Richard E; Song, Cai; Kalueff, Allan V

    2016-01-01

    Neurodevelopmental disorders (NDDs) are common and severely debilitating. Their chronic nature and reliance on both genetic and environmental factors makes studying NDDs and their treatment a challenging task. Herein, the authors discuss the neurobiological mechanisms of NDDs, and present recommendations on their translational research and therapy, outlined by the International Stress and Behavior Society. Various drugs currently prescribed to treat NDDs also represent a highly diverse group. Acting on various neurotransmitter and physiological systems, these drugs often lack specificity of action, and are commonly used to treat multiple other psychiatric conditions. There has also been relatively little progress in the development of novel medications to treat NDDs. Based on clinical, preclinical and translational models of NDDs, our recommendations cover a wide range of methodological approaches and conceptual strategies. To improve pharmacotherapy and drug discovery for NDDs, we need a stronger emphasis on targeting multiple endophenotypes, a better dissection of genetic/epigenetic factors or "hidden heritability," and a careful consideration of potential developmental/trophic roles of brain neurotransmitters. The validity of animal NDD models can be improved through discovery of novel (behavioral, physiological and neuroimaging) biomarkers, applying proper environmental enrichment, widening the spectrum of model organisms, targeting developmental trajectories of NDD-related behaviors and comorbid conditions beyond traditional NDDs. While these recommendations cannot be addressed all in once, our increased understanding of NDD pathobiology may trigger innovative cross-disciplinary research expanding beyond traditional methods and concepts.

  6. Co-variability of S 6+ , S 4+ , and S 2- in apatite as a function of oxidation state: Implications for a new oxybarometer

    SciTech Connect

    Konecke, Brian A.; Fiege, Adrian; Simon, Adam C.

    In this study, we use micro-X-ray absorption near-edge structures (μ-XANES) spectroscopy at the S K-edge to investigate the oxidation state of S in natural magmatic-hydrothermal apatite (Durango, Mexico, and Mina Carmen, Chile) and experimental apatites crystallized from volatile-saturated lamproitic melts at 1000 °C and 300 MPa over a broad range of oxygen fugacities [( Embedded Image , FMQ+1.2, FMQ+3; FMQ = fayalite-magnetite-quartz solid buffer]. The data are used to test the hypothesis that S oxidation states other than S6+ may substitute into the apatite structure. Peak energies corresponding to sulfate S6+ (~2482 eV), sulfite S4+ (~2478 eV), and sulfide S2-more » (~2470 eV) were observed in apatite, and the integrated areas of the different sulfur peaks correspond to changes in Embedded Image and bulk S content. Here, multiple tests confirmed that the S oxidation state in apatite remains constant when exposed to the synchrotron beam, at least for up to 1 h exposure (i.e., no irradiation damages). To our knowledge, this observation makes apatite the first mineral to incorporate reduced (S2-), intermediate (S4+), and oxidized (S6+) S in variable proportions as a function of the prevailing Embedded Image of the system. Apatites crystallized under oxidizing conditions (FMQ+1.2 and FMQ+3), where the S6+/STotal peak area ratio in the coexisting glass (i.e., quenched melt) is ~1, are dominated by S6+ with a small contribution of S4+, whereas apatites crystallizing at reduced conditions (FMQ) contain predominantly S2-, lesser amounts of S6+, and possibly traces of S4+. A sulfur oxidation state vs. S concentration analytical line transect across hydrothermally altered apatite from the Mina Carmen iron oxide-apatite (IOA) deposit (Chile) demonstrates that apatite can become enriched in S4+ relative to S6+, indicating metasomatic overprinting via a SO2-bearing fluid or vapor phase. This XANES study demonstrates that as the Embedded Image increases from FQM to FMQ+1

  7. Synaptically Driven Phosphorylation of Ribosomal Protein S6 Is Differentially Regulated at Active Synapses versus Dendrites and Cell Bodies by MAPK and PI3K/mTOR Signaling Pathways

    ERIC Educational Resources Information Center

    Pirbhoy, Patricia Salgado; Farris, Shannon; Steward, Oswald

    2017-01-01

    High-frequency stimulation of the medial perforant path triggers robust phosphorylation of ribosomal protein S6 (rpS6) in activated dendritic domains and granule cell bodies. Here we dissect the signaling pathways responsible for synaptically driven rpS6 phosphorylation in the dentate gyrus using pharmacological agents to inhibit PI3-kinase/mTOR…

  8. Rapamycin inhibits mTOR/p70S6K activation in CA3 region of the hippocampus of the rat and impairs long term memory.

    PubMed

    Lana, D; Di Russo, J; Mello, T; Wenk, G L; Giovannini, M G

    2017-01-01

    The present study was aimed at establishing whether the mTOR pathway and its downstream effector p70S6K in CA3 pyramidal neurons are under the modulation of the cholinergic input to trigger the formation of long term memories, similar to what we demonstrated in CA1 hippocampus. We performed in vivo behavioral experiments using the step down inhibitory avoidance test in adult Wistar rats to evaluate memory formation under different conditions. We examined the effects of rapamycin, an inhibitor of mTORC1 formation, scopolamine, a muscarinic receptor antagonist or mecamylamine, a nicotinic receptor antagonist, on short and long term memory formation and on the functionality of the mTOR pathway. Acquisition was conducted 30min after i.c.v. injection of rapamycin. Recall testing was performed 1h, 4h or 24h after acquisition. We found that (1) mTOR and p70S6K activation in CA3 pyramidal neurons were involved in long term memory formation; (2) rapamycin significantly inhibited mTOR and of p70S6K activation at 4h, and long term memory impairment 24h after acquisition; (3) scopolamine impaired short but not long term memory, with an early increase of mTOR/p70S6K activation at 1h followed by stabilization at longer times; (4) mecamylamine and scopolamine co-administration impaired short term memory at 1h and 4h and reduced the scopolamine-induced increase of mTOR/p70S6K activation at 1h and 4h; (5) mecamylamine and scopolamine treatment did not impair long term memory formation; (6) unexpectedly, rapamycin increased mTORC2 activation in microglial cells. Our results demonstrate that in CA3 pyramidal neurons the mTOR/p70S6K pathway is under the modulation of the cholinergic system and is involved in long-term memory encoding, and are consistent with