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Sample records for multiple endpoint embryonic

  1. Comparing three novel endpoints for developmental osteotoxicity in the embryonic stem cell test

    SciTech Connect

    Nieden, Nicole I. zur; Davis, Lesley A.; Rancourt, Derrick E.

    2010-09-01

    Birth defects belong to the most serious side effects of pharmaceutical compounds or environmental chemicals. In vivo, teratogens most often affect the normal development of bones, causing growth retardation, limb defects or craniofacial malformations. The embryonic stem cell test (EST) is one of the most promising models that allow the in vitro prediction of embryotoxicity, with one of its endpoints being bone tissue development. The present study was designed to describe three novel inexpensive endpoints to assess developmental osteotoxicity using the model compounds penicillin G (non-teratogenic), 5-fluorouracil (strong teratogen) and all-trans retinoic acid (bone teratogen). These three endpoints were: quantification of matrix incorporated calcium by (1) morphometric analysis and (2) measurement of calcium levels as well as (3) activity of alkaline phosphatase, an enzyme involved in matrix calcification. To evaluate our data, we have compared the concentration curves and resulting ID{sub 50}s of the new endpoints with mRNA expression for osteocalcin. Osteocalcin is an exclusive marker found only in mineralized tissues, is regulated upon compound treatment and reliably predicts the potential of a chemical entity acting as a bone teratogen. By comparing the new endpoints to quantitative expression of osteocalcin, which we previously identified as suitable to detect developmental osteotoxicity, we were ultimately able to illustrate IMAGE analysis and Ca{sup 2+} deposition assays as two reliable novel endpoints for the EST. This is of particular importance for routine industrial assessment of novel compounds as these two new endpoints may substitute previously used molecular read-out methods, which are often costly and time-consuming.

  2. Endpoint matrix: a conceptual tool to promote consideration of the multiple dimensions of humane endpoints.

    PubMed

    Ashall, Vanessa; Millar, Kate

    2014-01-01

    This paper proposes a framework to support appropriate application of endpoints in animal experiments. It is recommended that unpredicted endpoints should be explicitly considered alongside scientific endpoints and justifiable endpoints as the three types of endpoint which comprise the "humane." We suggest there is a need for clear identification of each type of endpoint and an understanding of the interactions between these types. The use of an "endpoint matrix" during study planning is proposed to promote methodically sound and consistent definition, determination, and detection of unpredicted, scientific, and justifiable endpoints in animal experiments. It is claimed that the further development and use of this tool will support a more effective and harmonized practical application of humane endpoints for all animal use in line with best practice recommendations. PMID:24794004

  3. Survival analysis of cancer patients with multiple endpoints using global score test methodology

    NASA Astrophysics Data System (ADS)

    Zain, Zakiyah; Whitehead, John

    2014-06-01

    Progression-free survival (PFS), time-to-progression (TTP) and overall survival (OS) are examples of multiple endpoints commonly used in clinical trials of cancer patients. PFS is increasingly used as a primary endpoint in evaluation of patients with solid tumors, while multiple endpoints are often analysed independently. These endpoints are indeed correlated and it is desirable to evaluate effectiveness of treatments by means of a single parameter. In this paper, a single overall treatment effect is provided by combining the univariate score statistics for comparing treatments with respect to each survival endpoint. This global score test methodology was applied in analysis of 330 patients with an aggressive cancer, each with two endpoints recorded, T1 and T2, relating to disease progression and death respectively. The values of score statistics obtained from the proposed method matched closely those from the logrank test. Meanwhile, the correlations between the two score test statistics were found to be similar to those computed using the established Wei, Lin and Weissfeld method. Simulations further confirmed the consistent performance of this new method in analysis of bivariate survival data.

  4. Power and sample size when multiple endpoints are considered.

    PubMed

    Senn, Stephen; Bretz, Frank

    2007-01-01

    A common approach to analysing clinical trials with multiple outcomes is to control the probability for the trial as a whole of making at least one incorrect positive finding under any configuration of true and false null hypotheses. Popular approaches are to use Bonferroni corrections or structured approaches such as, for example, closed-test procedures. As is well known, such strategies, which control the family-wise error rate, typically reduce the type I error for some or all the tests of the various null hypotheses to below the nominal level. In consequence, there is generally a loss of power for individual tests. What is less well appreciated, perhaps, is that depending on approach and circumstances, the test-wise loss of power does not necessarily lead to a family wise loss of power. In fact, it may be possible to increase the overall power of a trial by carrying out tests on multiple outcomes without increasing the probability of making at least one type I error when all null hypotheses are true. We examine two types of problems to illustrate this. Unstructured testing problems arise typically (but not exclusively) when many outcomes are being measured. We consider the case of more than two hypotheses when a Bonferroni approach is being applied while for illustration we assume compound symmetry to hold for the correlation of all variables. Using the device of a latent variable it is easy to show that power is not reduced as the number of variables tested increases, provided that the common correlation coefficient is not too high (say less than 0.75). Afterwards, we will consider structured testing problems. Here, multiplicity problems arising from the comparison of more than two treatments, as opposed to more than one measurement, are typical. We conduct a numerical study and conclude again that power is not reduced as the number of tested variables increases. PMID:17674404

  5. Association of response endpoints with survival outcomes in multiple myeloma

    PubMed Central

    Lonial, S; Anderson, K C

    2014-01-01

    Since the introduction of the proteasome inhibitor bortezomib and the immunomodulatory drugs (IMiDs) thalidomide and lenalidomide, more patients with multiple myeloma are achieving deep, durable responses and disease control, and are living longer. These improvements have afforded more robust analyses of the relationship between response and survival. Generally, these studies have demonstrated that improvements in the quality of response across all stages of treatment are associated with better disease control and longer survival. Thus, achievement of maximal response should be strongly considered, particularly in the frontline setting, but must also be balanced with tolerability, quality of life and patient preferences. In select patients, achievement of a lesser response may be adequate to prolong survival, and attempts to treat these patients to a deeper response may place them at unnecessary risk without significant benefit. Maintenance therapy has been shown to improve the quality of response and disease control and, in some studies, survival. Studies support maintenance therapy for high-risk patients as a standard of care, and there are emerging data supporting maintenance therapy in standard-risk patients to improve progression-free and possibly overall survival. Multidrug regimens combining a proteasome inhibitor and an IMiD have shown exceptional response outcomes with acceptable increases in toxicity in both the frontline and salvage settings, and are becoming a standard treatment approach. Moving forward, the use of immunophenotypic and molecular response criteria will be essential in better understanding the impact of highly active and continuous treatment regimens across myeloma patient populations. Future translational studies will help to develop antimyeloma agents to their fullest potential. The introduction of novel targeted therapies, including the IMiD pomalidomide and the proteasome inhibitors carfilzomib and ixazomib (MLN9708), will provide

  6. Association of response endpoints with survival outcomes in multiple myeloma.

    PubMed

    Lonial, S; Anderson, K C

    2014-02-01

    Since the introduction of the proteasome inhibitor bortezomib and the immunomodulatory drugs (IMiDs) thalidomide and lenalidomide, more patients with multiple myeloma are achieving deep, durable responses and disease control, and are living longer. These improvements have afforded more robust analyses of the relationship between response and survival. Generally, these studies have demonstrated that improvements in the quality of response across all stages of treatment are associated with better disease control and longer survival. Thus, achievement of maximal response should be strongly considered, particularly in the frontline setting, but must also be balanced with tolerability, quality of life and patient preferences. In select patients, achievement of a lesser response may be adequate to prolong survival, and attempts to treat these patients to a deeper response may place them at unnecessary risk without significant benefit. Maintenance therapy has been shown to improve the quality of response and disease control and, in some studies, survival. Studies support maintenance therapy for high-risk patients as a standard of care, and there are emerging data supporting maintenance therapy in standard-risk patients to improve progression-free and possibly overall survival. Multidrug regimens combining a proteasome inhibitor and an IMiD have shown exceptional response outcomes with acceptable increases in toxicity in both the frontline and salvage settings, and are becoming a standard treatment approach. Moving forward, the use of immunophenotypic and molecular response criteria will be essential in better understanding the impact of highly active and continuous treatment regimens across myeloma patient populations. Future translational studies will help to develop antimyeloma agents to their fullest potential. The introduction of novel targeted therapies, including the IMiD pomalidomide and the proteasome inhibitors carfilzomib and ixazomib (MLN9708), will provide

  7. Bayesian meta-analytical methods to incorporate multiple surrogate endpoints in drug development process.

    PubMed

    Bujkiewicz, Sylwia; Thompson, John R; Riley, Richard D; Abrams, Keith R

    2016-03-30

    A number of meta-analytical methods have been proposed that aim to evaluate surrogate endpoints. Bivariate meta-analytical methods can be used to predict the treatment effect for the final outcome from the treatment effect estimate measured on the surrogate endpoint while taking into account the uncertainty around the effect estimate for the surrogate endpoint. In this paper, extensions to multivariate models are developed aiming to include multiple surrogate endpoints with the potential benefit of reducing the uncertainty when making predictions. In this Bayesian multivariate meta-analytic framework, the between-study variability is modelled in a formulation of a product of normal univariate distributions. This formulation is particularly convenient for including multiple surrogate endpoints and flexible for modelling the outcomes which can be surrogate endpoints to the final outcome and potentially to one another. Two models are proposed, first, using an unstructured between-study covariance matrix by assuming the treatment effects on all outcomes are correlated and second, using a structured between-study covariance matrix by assuming treatment effects on some of the outcomes are conditionally independent. While the two models are developed for the summary data on a study level, the individual-level association is taken into account by the use of the Prentice's criteria (obtained from individual patient data) to inform the within study correlations in the models. The modelling techniques are investigated using an example in relapsing remitting multiple sclerosis where the disability worsening is the final outcome, while relapse rate and MRI lesions are potential surrogates to the disability progression. PMID:26530518

  8. A Speech Endpoint Detection Algorithm Based on BP Neural Network and Multiple Features

    NASA Astrophysics Data System (ADS)

    Shi, Yong-Qiang; Li, Ru-Wei; Zhang, Shuang; Wang, Shuai; Yi, Xiao-Qun

    Focusing on a sharp decline in the performance of endpoint detection algorithm in a complicated noise environment, a new speech endpoint detection method based on BPNN (back propagation neural network) and multiple features is presented. Firstly, maximum of short-time autocorrelation function and spectrum variance of speech signals are extracted respectively. Secondly, these feature vectors as the input of BP neural network are trained and modeled and then the Genetic Algorithm is used to optimize the BP Neural Network. Finally, the signal's type is determined according to the output of Neural Network. The experiments show that the correct rate of this proposed algorithm is improved, because this method has better robustness and adaptability than algorithm based on maximum of short-time autocorrelation function or spectrum variance.

  9. Toxicity assessment through multiple endpoint bioassays in soils posing environmental risk according to regulatory screening values.

    PubMed

    Rodriguez-Ruiz, A; Asensio, V; Zaldibar, B; Soto, M; Marigómez, I

    2014-01-01

    Toxicity profiles of two soils (a brownfield in Legazpi and an abandoned iron mine in Zugaztieta; Basque Country) contaminated with several metals (As, Zn, Pb and Cu in Legazpi; Zn, Pb, Cd and Cu in Zugaztieta) and petroleum hydrocarbons (in Legazpi) were determined using a multi-endpoint bioassay approach. Investigated soils exceeded screening values (SVs) of regulatory policies in force (Basque Country; Europe). Acute and chronic toxicity bioassays were conducted with a selected set of test species (Vibrio fischeri, Dictyostelium discoideum, Lactuca sativa, Raphanus sativus and Eisenia fetida) in combination with chemical analysis of soils and elutriates, as well as with bioaccumulation studies in earthworms. The sensitivity of the test species and the toxicity endpoints varied depending on the soil. It was concluded that whilst Zugaztieta soil showed very little or no toxicity, Legazpi soil was toxic according to almost all the toxicity tests (solid phase Microtox, D. discoideum inhibition of fruiting body formation and developmental cycle solid phase assays, lettuce seed germination and root elongation test, earthworm acute toxicity and reproduction tests, D. discoideum cell viability and replication elutriate assays). Thus, albeit both soils had similar SVs, their ecotoxicological risk, and therefore the need for intervening, was different for each soil as unveiled after toxicity profiling based on multiple endpoint bioassays. Such a toxicity profiling approach is suitable to be applied for scenario-targeted soil risk assessment in those cases where applicable national/regional soil legislation based on SVs demands further toxicity assessment. PMID:24819436

  10. The impact of multiple endpoint dependency on Q and I(2) in meta-analysis.

    PubMed

    Thompson, Christopher Glen; Becker, Betsy Jane

    2014-09-01

    A common assumption in meta-analysis is that effect sizes are independent. When correlated effect sizes are analyzed using traditional univariate techniques, this assumption is violated. This research assesses the impact of dependence arising from treatment-control studies with multiple endpoints on homogeneity measures Q and I(2) in scenarios using the unbiased standardized-mean-difference effect size. Univariate and multivariate meta-analysis methods are examined. Conditions included different overall outcome effects, study sample sizes, numbers of studies, between-outcomes correlations, dependency structures, and ways of computing the correlation. The univariate approach used typical fixed-effects analyses whereas the multivariate approach used generalized least-squares (GLS) estimates of a fixed-effects model, weighted by the inverse variance-covariance matrix. Increased dependence among effect sizes led to increased Type I error rates from univariate models. When effect sizes were strongly dependent, error rates were drastically higher than nominal levels regardless of study sample size and number of studies. In contrast, using GLS estimation to account for multiple-endpoint dependency maintained error rates within nominal levels. Conversely, mean I(2) values were not greatly affected by increased amounts of dependency. Last, we point out that the between-outcomes correlation should be estimated as a pooled within-groups correlation rather than using a full-sample estimator that does not consider treatment/control group membership. PMID:26052849

  11. A convenient formula for sample size calculations in clinical trials with multiple co-primary continuous endpoints.

    PubMed

    Sugimoto, Tomoyuki; Sozu, Takashi; Hamasaki, Toshimitsu

    2012-01-01

    The clinical efficacy of a new treatment may often be better evaluated by two or more co-primary endpoints. Recently, in pharmaceutical drug development, there has been increasing discussion regarding establishing statistically significant favorable results on more than one endpoint in comparisons between treatments, which is referred to as a problem of multiple co-primary endpoints. Several methods have been proposed for calculating the sample size required to design a trial with multiple co-primary correlated endpoints. However, because these methods require users to have considerable mathematical sophistication and knowledge of programming techniques, their application and spread may be restricted in practice. To improve the convenience of these methods, in this paper, we provide a useful formula with accompanying numerical tables for sample size calculations to design clinical trials with two treatments, where the efficacy of a new treatment is demonstrated on continuous co-primary endpoints. In addition, we provide some examples to illustrate the sample size calculations made using the formula. Using the formula and the tables, which can be read according to the patterns of correlations and effect size ratios expected in multiple co-primary endpoints, makes it convenient to evaluate the required sample size promptly. PMID:22415870

  12. Effects of ivermectin on Danio rerio: a multiple endpoint approach: behaviour, weight and subcellular markers.

    PubMed

    Domingues, I; Oliveira, R; Soares, A M V M; Amorim, M J B

    2016-04-01

    Ivermectin (IVM) is a broad acting antihelmintic used in various veterinary pharmaceuticals. It has been shown that IVM enters the aquatic compartment and adversely affects organisms including fish. This study is based on the hypothesis that long term exposure to IVM affects fish and thus, the main objective was to assess the chronic effects of 0.25 and 25 µg IVM/L to zebrafish using multiple endpoints representative of several levels of biological organization: weight, behaviour (swimming and feeding) and subcellular markers including biomarkers for oestrogenicity (vitellogenin-VTG), oxidative stress (catalase-CAT and glutathione-S-transferase-GST) and neurotransmission (cholinesterase-ChE). Concentrations as low as 0.25 µg IVM/L disrupted the swimming behaviour, causing fish to spend more time at the bottom of aquaria. Such reduction of the swimming performance affected the feeding ability which is likely responsible for the weight loss. The effects on weight were gender differentiated, being more pronounced in males (0.25 µg IVM/L) than in females (25 µg IVM/L). Fish exposed to 25 µg/L exhibited darker coloration and mild curvature of the spine. No effects on VTG and AChE were observed, but a reduction on CAT and GST levels was observed in fish exposed to 25 µg IVM/L, although these alterations probably only reflect the general condition of the fish which was significantly compromised at this concentration. Despite that predicted environmental concentrations of IVM are below 0.25 µg/L, the behavioural effects may be translated into important ecological impacts, e.g. at predator-prey interactions where fish competitive advantage can be decreased. Future work should address the link between behaviour disruption and population fitness. The current study was based on a one experiment and multiple endpoint (anchored) approach, allowing the results to be integrated and linked towards a mechanistic understanding. PMID:26769347

  13. Use of multiple endpoints and approval paths depicts a decade of FDA oncology drug approvals.

    PubMed

    Shea, Michael B; Roberts, Samantha A; Walrath, Jessica C; Allen, Jeff D; Sigal, Ellen V

    2013-07-15

    This study explores the historic use of different endpoints to support regular and accelerated approval of cancer drugs between 2002 and 2012. In the past 10 years, two thirds of oncology regular approvals were based on endpoints other than overall survival. More than three quarters of accelerated approvals were based on response rates. The accelerated approval program has been heavily used over this time period, with one third of all approved oncology indications receiving accelerated approval. At times, critics have characterized the agency as rigid and unpredictable. This research describes the degree of regulatory flexibility that U.S. Food and Drug Administration and drug sponsors have used over the past decade in the development of new treatments for cancer. PMID:23665737

  14. A marginal rank-based inverse normal transformation approach to comparing multiple clinical trial endpoints.

    PubMed

    Cai, Xiaoyu; Li, Huiyun; Liu, Aiyi

    2016-08-30

    The increase in incidence of obesity and chronic diseases and their health care costs have raised the importance of quality diet on the health policy agendas. The healthy eating index is an important measure for diet quality which consists of 12 components derived from ratios of dependent variables with distributions hard to specify, measurement errors and excessive zero observations difficult to model parametrically. Hypothesis testing involving data of such nature poses challenges because the widely used multiple comparison procedures such as Hotelling's T(2) test and Bonferroni correction may suffer from substantial loss of efficiency. We propose a marginal rank-based inverse normal transformation approach to normalizing the marginal distribution of the data before employing a multivariate test procedure. Extensive simulation was conducted to demonstrate the ability of the proposed approach to adequately control the type I error rate as well as increase the power of the test, with data particularly from non-symmetric or heavy-tailed distributions. The methods are exemplified with data from a dietary intervention study for type I diabetic children. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. PMID:26990442

  15. Generative models: Human embryonic stem cells and multiple modeling relations.

    PubMed

    Fagan, Melinda Bonnie

    2016-04-01

    Model organisms are at once scientific models and concrete living things. It is widely assumed by philosophers of science that (1) model organisms function much like other kinds of models, and (2) that insofar as their scientific role is distinctive, it is in virtue of representing a wide range of biological species and providing a basis for generalizations about those targets. This paper uses the case of human embryonic stem cells (hESC) to challenge both assumptions. I first argue that hESC can be considered model organisms, analogous to classic examples such as Escherichia coli and Drosophila melanogaster. I then discuss four contrasts between the epistemic role of hESC in practice, and the assumptions about model organisms noted above. These contrasts motivate an alternative view of model organisms as a network of systems related constructively and developmentally to one another. I conclude by relating this result to other accounts of model organisms in recent philosophy of science. PMID:27083092

  16. Analyzing multiple endpoints in clinical trials of pain treatments: IMMPACT recommendations. Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials.

    PubMed

    Turk, Dennis C; Dworkin, Robert H; McDermott, Michael P; Bellamy, Nicholas; Burke, Laurie B; Chandler, Julie M; Cleeland, Charles S; Cowan, Penney; Dimitrova, Rozalina; Farrar, John T; Hertz, Sharon; Heyse, Joseph F; Iyengar, Smriti; Jadad, Alejandro R; Jay, Gary W; Jermano, John A; Katz, Nathaniel P; Manning, Donald C; Martin, Susan; Max, Mitchell B; McGrath, Patrick; McQuay, Henry J; Quessy, Steve; Rappaport, Bob A; Revicki, Dennis A; Rothman, Margaret; Stauffer, Joseph W; Svensson, Ola; White, Richard E; Witter, James

    2008-10-31

    The increasing complexity of randomized clinical trials and the practice of obtaining a wide variety of measurements from study participants have made the consideration of multiple endpoints a critically important issue in the design, analysis, and interpretation of clinical trials. Failure to consider important outcomes can limit the validity and utility of clinical trials; specifying multiple endpoints for the evaluation of treatment efficacy, however, can increase the rate of false positive conclusions about the efficacy of a treatment. We describe the use of multiple endpoints in the design, analysis, and interpretation of pain clinical trials, and review available strategies and methods for addressing multiplicity. To decrease the probability of a Type I error (i.e., the likelihood of obtaining statistically significant results by chance) in pain clinical trials, the use of gatekeeping procedures and other methods that correct for multiple analyses is recommended when a single primary endpoint does not adequately reflect the overall benefits of treatment. We emphasize the importance of specifying in advance the outcomes and clinical decision rule that will serve as the basis for determining that a treatment is efficacious and the methods that will be used to control the overall Type I error rate. PMID:18706763

  17. Multiple cell and population-level interactions with mouse embryonic stem cell heterogeneity.

    PubMed

    Cannon, Danielle; Corrigan, Adam M; Miermont, Agnes; McDonel, Patrick; Chubb, Jonathan R

    2015-08-15

    Much of development and disease concerns the generation of gene expression differences between related cells sharing similar niches. However, most analyses of gene expression only assess population and time-averaged levels of steady-state transcription. The mechanisms driving differentiation are buried within snapshots of the average cell, lacking dynamic information and the diverse regulatory history experienced by individual cells. Here, we use a quantitative imaging platform with large time series data sets to determine the regulation of developmental gene expression by cell cycle, lineage, motility and environment. We apply this technology to the regulation of the pluripotency gene Nanog in mouse embryonic stem cells. Our data reveal the diversity of cell and population-level interactions with Nanog dynamics and heterogeneity, and how this regulation responds to triggers of pluripotency. Cell cycles are highly heterogeneous and cycle time increases with Nanog reporter expression, with longer, more variable cycle times as cells approach ground-state pluripotency. Nanog reporter expression is highly stable over multiple cell generations, with fluctuations within cycles confined by an attractor state. Modelling reveals an environmental component to expression stability, in addition to any cell-autonomous behaviour, and we identify interactions of cell density with both cycle behaviour and Nanog. Rex1 expression dynamics showed shared and distinct regulatory effects. Overall, our observations of multiple partially overlapping dynamic heterogeneities imply complex cell and environmental regulation of pluripotent cell behaviour, and suggest simple deterministic views of stem cell states are inappropriate. PMID:26209649

  18. Multiple cell and population-level interactions with mouse embryonic stem cell heterogeneity

    PubMed Central

    Cannon, Danielle; Corrigan, Adam M.; Miermont, Agnes; McDonel, Patrick; Chubb, Jonathan R.

    2015-01-01

    Much of development and disease concerns the generation of gene expression differences between related cells sharing similar niches. However, most analyses of gene expression only assess population and time-averaged levels of steady-state transcription. The mechanisms driving differentiation are buried within snapshots of the average cell, lacking dynamic information and the diverse regulatory history experienced by individual cells. Here, we use a quantitative imaging platform with large time series data sets to determine the regulation of developmental gene expression by cell cycle, lineage, motility and environment. We apply this technology to the regulation of the pluripotency gene Nanog in mouse embryonic stem cells. Our data reveal the diversity of cell and population-level interactions with Nanog dynamics and heterogeneity, and how this regulation responds to triggers of pluripotency. Cell cycles are highly heterogeneous and cycle time increases with Nanog reporter expression, with longer, more variable cycle times as cells approach ground-state pluripotency. Nanog reporter expression is highly stable over multiple cell generations, with fluctuations within cycles confined by an attractor state. Modelling reveals an environmental component to expression stability, in addition to any cell-autonomous behaviour, and we identify interactions of cell density with both cycle behaviour and Nanog. Rex1 expression dynamics showed shared and distinct regulatory effects. Overall, our observations of multiple partially overlapping dynamic heterogeneities imply complex cell and environmental regulation of pluripotent cell behaviour, and suggest simple deterministic views of stem cell states are inappropriate. PMID:26209649

  19. Endpoints of resuscitation.

    PubMed

    Cestero, Ramon F; Dent, Daniel L

    2015-04-01

    Despite the multiple causes of the shock state, all causes possess the common abnormality of oxygen supply not meeting tissue metabolic demands. Compensatory mechanisms may mask the severity of hypoxemia and hypoperfusion, since catecholamines and extracellular fluid shifts initially compensate for the physiologic derangements associated with patients in shock. Despite the achievement of normal physiologic parameters after resuscitation, significant metabolic acidosis may continue to be present in the tissues, as evidenced by increased lactate levels and metabolic acidosis. This review discusses the major endpoints of resuscitation in clinical use. PMID:25814109

  20. Incorporation of individual-patient data in network meta-analysis for multiple continuous endpoints, with application to diabetes treatment.

    PubMed

    Hong, Hwanhee; Fu, Haoda; Price, Karen L; Carlin, Bradley P

    2015-09-10

    Availability of individual patient-level data (IPD) broadens the scope of network meta-analysis (NMA) and enables us to incorporate patient-level information. Although IPD is a potential gold mine in biomedical areas, methodological development has been slow owing to limited access to such data. In this paper, we propose a Bayesian IPD NMA modeling framework for multiple continuous outcomes under both contrast-based and arm-based parameterizations. We incorporate individual covariate-by-treatment interactions to facilitate personalized decision making. Furthermore, we can find subpopulations performing well with a certain drug in terms of predictive outcomes. We also impute missing individual covariates via an MCMC algorithm. We illustrate this approach using diabetes data that include continuous bivariate efficacy outcomes and three baseline covariates and show its practical implications. Finally, we close with a discussion of our results, a review of computational challenges, and a brief description of areas for future research. PMID:25924975

  1. Embryonic stem cell-specific microRNAs contribute to pluripotency by inhibiting regulators of multiple differentiation pathways.

    PubMed

    Gruber, Andreas J; Grandy, William A; Balwierz, Piotr J; Dimitrova, Yoana A; Pachkov, Mikhail; Ciaudo, Constance; Nimwegen, Erik van; Zavolan, Mihaela

    2014-08-01

    The findings that microRNAs (miRNAs) are essential for early development in many species and that embryonic miRNAs can reprogram somatic cells into induced pluripotent stem cells suggest that these miRNAs act directly on transcriptional and chromatin regulators of pluripotency. To elucidate the transcription regulatory networks immediately downstream of embryonic miRNAs, we extended the motif activity response analysis approach that infers the regulatory impact of both transcription factors (TFs) and miRNAs from genome-wide expression states. Applying this approach to multiple experimental data sets generated from mouse embryonic stem cells (ESCs) that did or did not express miRNAs of the ESC-specific miR-290-295 cluster, we identified multiple TFs that are direct miRNA targets, some of which are known to be active during cell differentiation. Our results provide new insights into the transcription regulatory network downstream of ESC-specific miRNAs, indicating that these miRNAs act on cell cycle and chromatin regulators at several levels and downregulate TFs that are involved in the innate immune response. PMID:25030899

  2. Embryonic stem cell-specific microRNAs contribute to pluripotency by inhibiting regulators of multiple differentiation pathways

    PubMed Central

    Gruber, Andreas J.; Grandy, William A.; Balwierz, Piotr J.; Dimitrova, Yoana A.; Pachkov, Mikhail; Ciaudo, Constance; van Nimwegen, Erik; Zavolan, Mihaela

    2014-01-01

    The findings that microRNAs (miRNAs) are essential for early development in many species and that embryonic miRNAs can reprogram somatic cells into induced pluripotent stem cells suggest that these miRNAs act directly on transcriptional and chromatin regulators of pluripotency. To elucidate the transcription regulatory networks immediately downstream of embryonic miRNAs, we extended the motif activity response analysis approach that infers the regulatory impact of both transcription factors (TFs) and miRNAs from genome-wide expression states. Applying this approach to multiple experimental data sets generated from mouse embryonic stem cells (ESCs) that did or did not express miRNAs of the ESC-specific miR-290-295 cluster, we identified multiple TFs that are direct miRNA targets, some of which are known to be active during cell differentiation. Our results provide new insights into the transcription regulatory network downstream of ESC-specific miRNAs, indicating that these miRNAs act on cell cycle and chromatin regulators at several levels and downregulate TFs that are involved in the innate immune response. PMID:25030899

  3. EndPoints 2000

    Energy Science and Technology Software Center (ESTSC)

    2009-08-13

    The application leads the user through a logical framework to determine the minimum effort and cost necessary to reach the desired end state for each space, system, and facility. Endpoints are used to plan the project work, track and manage the determination, management, verification, and closure of D&D endpoints, consistent with DOE End Point guidance documents.

  4. Rationally optimized cryopreservation of multiple mouse embryonic stem cell lines: I—Comparative Fundamental Cryobiology of Multiple Mouse Embryonic Stem Cell Lines and the Implications for Embryonic Stem Cell Cryopreservation Protocols

    PubMed Central

    Kashuba, Corinna M.; Benson, James D.; Critser, John K.

    2014-01-01

    The post-thaw recovery of mouse embryonic stem cells (mESCs) is often assumed to be adequate with current methods. However as this publication will show, this recovery of viable cells actually varies significantly by genetic background. Therefore there is a need to improve the efficiency and reduce the variability of current mESC cryopreservation methods. To address this need, we employed the principles of fundamental cryobiology to improve the cryopreservation protocol of four mESC lines from different genetic backgrounds (BALB/c, CBA, FVB, and 129R1 mESCs) through a comparative study characterizing the membrane permeability characteristics and membrane integrity osmotic tolerance limits of each cell line. In the companion paper, these values were used to predict optimal cryoprotectants, cooling rates, warming rates, and plunge temperatures, and then these predicted optimal protocols were validated against standard freezing protocols. PMID:24384367

  5. Rationally optimized cryopreservation of multiple mouse embryonic stem cell lines: I--Comparative fundamental cryobiology of multiple mouse embryonic stem cell lines and the implications for embryonic stem cell cryopreservation protocols.

    PubMed

    Kashuba, Corinna M; Benson, James D; Critser, John K

    2014-04-01

    The post-thaw recovery of mouse embryonic stem cells (mESCs) is often assumed to be adequate with current methods. However as this publication will show, this recovery of viable cells actually varies significantly by genetic background. Therefore there is a need to improve the efficiency and reduce the variability of current mESC cryopreservation methods. To address this need, we employed the principles of fundamental cryobiology to improve the cryopreservation protocol of four mESC lines from different genetic backgrounds (BALB/c, CBA, FVB, and 129R1 mESCs) through a comparative study characterizing the membrane permeability characteristics and membrane integrity osmotic tolerance limits of each cell line. In the companion paper, these values were used to predict optimal cryoprotectants, cooling rates, warming rates, and plunge temperatures, and then these predicted optimal protocols were validated against standard freezing protocols. PMID:24384367

  6. Derivation of multiple cranial tissues and isolation of lens epithelium-like cells from human embryonic stem cells.

    PubMed

    Mengarelli, Isabella; Barberi, Tiziano

    2013-02-01

    Human embryonic stem cells (hESCs) provide a powerful tool to investigate early events occurring during human embryonic development. In the present study, we induced differentiation of hESCs in conditions that allowed formation of neural and non-neural ectoderm and to a lesser extent mesoderm. These tissues are required for correct specification of the neural plate border, an early embryonic transient structure from which neural crest cells (NCs) and cranial placodes (CPs) originate. Although isolation of CP derivatives from hESCs has not been previously reported, isolation of hESC-derived NC-like cells has been already described. We performed a more detailed analysis of fluorescence-activated cell sorting (FACS)-purified cell populations using the surface antigens previously used to select hESC-derived NC-like cells, p75 and HNK-1, and uncovered their heterogeneous nature. In addition to the NC component, we identified a neural component within these populations using known surface markers, such as CD15 and FORSE1. We have further exploited this information to facilitate the isolation and purification by FACS of a CP derivative, the lens, from differentiating hESCs. Two surface markers expressed on lens cells, c-Met/HGFR and CD44, were used for positive selection of multiple populations with a simultaneous subtraction of the neural/NC component mediated by p75, HNK-1, and CD15. In particular, the c-Met/HGFR allowed early isolation of proliferative lens epithelium-like cells capable of forming lentoid bodies. Isolation of hESC-derived lens cells represents an important step toward the understanding of human lens development and regeneration and the devising of future therapeutic applications. PMID:23341438

  7. Derivation of Multiple Cranial Tissues and Isolation of Lens Epithelium-Like Cells From Human Embryonic Stem Cells

    PubMed Central

    2013-01-01

    Human embryonic stem cells (hESCs) provide a powerful tool to investigate early events occurring during human embryonic development. In the present study, we induced differentiation of hESCs in conditions that allowed formation of neural and non-neural ectoderm and to a lesser extent mesoderm. These tissues are required for correct specification of the neural plate border, an early embryonic transient structure from which neural crest cells (NCs) and cranial placodes (CPs) originate. Although isolation of CP derivatives from hESCs has not been previously reported, isolation of hESC-derived NC-like cells has been already described. We performed a more detailed analysis of fluorescence-activated cell sorting (FACS)-purified cell populations using the surface antigens previously used to select hESC-derived NC-like cells, p75 and HNK-1, and uncovered their heterogeneous nature. In addition to the NC component, we identified a neural component within these populations using known surface markers, such as CD15 and FORSE1. We have further exploited this information to facilitate the isolation and purification by FACS of a CP derivative, the lens, from differentiating hESCs. Two surface markers expressed on lens cells, c-Met/HGFR and CD44, were used for positive selection of multiple populations with a simultaneous subtraction of the neural/NC component mediated by p75, HNK-1, and CD15. In particular, the c-Met/HGFR allowed early isolation of proliferative lens epithelium-like cells capable of forming lentoid bodies. Isolation of hESC-derived lens cells represents an important step toward the understanding of human lens development and regeneration and the devising of future therapeutic applications. PMID:23341438

  8. Developmental regulation of the human embryonic beta-like globin gene is mediated by synergistic interactions among multiple tissue- and stage-specific elements.

    PubMed Central

    Trepicchio, W L; Dyer, M A; Baron, M H

    1993-01-01

    The stage-specific regulation of mammalian embryonic globin genes has been an experimentally elusive problem, in part because of the developmentally early timing of their expression. We have carried out a systematic analysis of truncation and internal deletion mutations within the 5'-flanking region of the human embryonic beta-like globin gene (epsilon) in erythroid and nonerythroid cell lines. Within a 670-bp region upstream from the constitutive promoter are multiple positive and negative control elements. Of these, a positive regulatory element (epsilon-PRE II) which is active only in embryonic erythroid cells is of particular interest. Remarkably, although it is inactive on its own, in the presence of other sequences located further upstream, it confers tissue- and developmental stage-specific expression on a constitutive epsilon-globin or heterologous promoter. The activity of epsilon-PRE II is also modulated by another positive regulatory domain located further downstream to direct erythroid cell-specific, but little or no embryonic stage-specific, transcription. A nuclear factor highly enriched in embryonic erythroid cells binds specifically within a 19-bp region of epsilon-PRE II. Nuclei from adult erythroid cells also contain a factor that binds to this region but forms a complex of faster electrophoretic mobility. We speculate that interactions between epsilon-PRE II and other upstream control elements play an important role in the developmental regulation of the human embryonic beta-like globin gene. Images PMID:8246963

  9. Concise Review: One Stone for Multiple Birds: Generating Universally Compatible Human Embryonic Stem Cells.

    PubMed

    Zheng, Dejin; Wang, Xiaofang; Xu, Ren-He

    2016-09-01

    With ongoing clinical trials, human embryonic stem cells (hESCs) have shown substantial potential for regenerative medicine. However, due to the mismatch of human leukocyte antigens (HLAs) between hESC-derived allografts and recipients, immunosuppressant regimens must be used to prevent immune rejection of the grafts. Considerable efforts have been devoted to overcoming this hurdle via the derivation and banking of human nuclear transfer ESCs, parthenogenetic ESCs, and induced pluripotent stem cells. However, ethical and safety concerns remain, hindering the application of these types of pluripotent cells. Other approaches have recently been explored to generate universally compatible hESCs through the silencing or deletion of HLAs or genes essential for HLA expression, including β-2-microglobulin and class-II MHC transactivator, as well as the induction of immunosuppression via the ectopic expression of non-classical HLAs (e.g., HLA-E and -G), cytotoxic T lymphocyte antigen 4 fused with immunoglobulin, and programmed death ligand-1. In this review, we introduce developments in this line of research and discuss strategies to reduce the tumorigenic concerns regarding hESCs, especially after they acquire the capability to escape immune surveillance. Stem Cells 2016;34:2269-2275. PMID:27251112

  10. EMBRYONIC CORONARY VASCULOGENESIS AND ANGIOGENESIS ARE REGULATED BY INTERACTIONS BETWEEN MULTIPLE FGFS AND VEGF AND ARE INFLUENCED BY MESENCHYMAL STEM CELLS

    PubMed Central

    Tomanek, Robert J.; Christensen, Lance P.; Simons, Michael; Murakami, Masahiro; Zheng, Wei; Schatteman, Gina C.

    2010-01-01

    In embryonic hearts explanted on collagen gels, epicardial cells delaminate and form vascular tubes, thus providing a model for coronary tubulogenesis. Using this model, we show that FGFs 1, 2, 4, 8, 9 and 18 contribute to tubulogenesis and that the availability of multiple FGFs provides the optimal tubulogenic response. Moreover, the FGF effects are VEGF dependent, while VEGF-induced tubulogenesis requires FGF signaling. The number of endothelial cells (ECs) is increased by all of the FGFs, while EC migration is significantly enhanced only by FGF-2 and FGF-18. Finally, addition of embryonic mesenchymal stem cells (EMSC) to the explants markedly enhances EC numbers and a 23-fold increase in SDF-1α, which is FGF dependent. Both explants and EMSCs produce SDF-1α. In conclusion, coronary tubulogenesis of embryonic epicardium: 1) is responsive to many FGF family members, 2) requires both FGF and VEGFA signaling, and 3) is responsive to EMSCs. PMID:20981833

  11. Scenario-targeted toxicity assessment through multiple endpoint bioassays in a soil posing unacceptable environmental risk according to regulatory screening values.

    PubMed

    Rodriguez-Ruiz, A; Etxebarria, J; Boatti, L; Marigómez, I

    2015-09-01

    Lanestosa is a chronically polluted site (derelict mine) where the soil (Lanestosa (LA) soil) exceeds screening values (SVs) of regulatory policies in force (Basque Country; Europe) for Zn, Pb and Cd. A scenario-targeted toxicity assessment was carried out on the basis of a multi-endpoint bioassay approach. Acute and chronic toxicity bioassays were conducted with selected test species (Vibrio fischeri, Dictyostelium discoideum, Lactuca sativa, Raphanus sativus and Eisenia fetida) in combination with chemical analysis of soils and elutriates and with bioaccumulation studies in earthworms. Besides, the toxicity profile was compared with that of the mine runoff (RO) soil and of a fresh artificially polluted soil (LAAPS) resembling LA soil pollutant profile. Extractability studies in LA soil revealed that Pb, Zn and Cd were highly available for exchange and/or release into the environment. Indeed, Pb and Zn were accumulated in earthworms and LA soil resulted to be toxic. Soil respiration, V. fischeri, vegetative and developmental cycles of D. discoideum and survival and juvenile production of E. fetida were severely affected. These results confirmed that LA soil had unacceptable environmental risk and demanded intervention. In contrast, although Pb and Zn concentrations in RO soil revealed also unacceptable risk, both metal extractability and toxicity were much lower than in LA soil. Thus, within the polluted site, the need for intervention varied between areas that posed dissimilar risk. Besides, since LAAPS, with a high exchangeable metal fraction, was the most toxic, ageing under in situ natural conditions seemingly contributed to attenuate LA soil risk. As a whole, combining multi-endpoint bioassays with scenario-targeted analysis (including leaching and ageing) provides reliable risk assessment in soils posing unacceptable environmental risk according to SVs, which is useful to optimise the required intervention measures. PMID:25940475

  12. ZFP57 recognizes multiple and closely spaced sequence motif variants to maintain repressive epigenetic marks in mouse embryonic stem cells

    PubMed Central

    Anvar, Zahra; Cammisa, Marco; Riso, Vincenzo; Baglivo, Ilaria; Kukreja, Harpreet; Sparago, Angela; Girardot, Michael; Lad, Shraddha; De Feis, Italia; Cerrato, Flavia; Angelini, Claudia; Feil, Robert; Pedone, Paolo V.; Grimaldi, Giovanna; Riccio, Andrea

    2016-01-01

    Imprinting Control Regions (ICRs) need to maintain their parental allele-specific DNA methylation during early embryogenesis despite genome-wide demethylation and subsequent de novo methylation. ZFP57 and KAP1 are both required for maintaining the repressive DNA methylation and H3-lysine-9-trimethylation (H3K9me3) at ICRs. In vitro, ZFP57 binds a specific hexanucleotide motif that is enriched at its genomic binding sites. We now demonstrate in mouse embryonic stem cells (ESCs) that SNPs disrupting closely-spaced hexanucleotide motifs are associated with lack of ZFP57 binding and H3K9me3 enrichment. Through a transgenic approach in mouse ESCs, we further demonstrate that an ICR fragment containing three ZFP57 motif sequences recapitulates the original methylated or unmethylated status when integrated into the genome at an ectopic position. Mutation of Zfp57 or the hexanucleotide motifs led to loss of ZFP57 binding and DNA methylation of the transgene. Finally, we identified a sequence variant of the hexanucleotide motif that interacts with ZFP57 both in vivo and in vitro. The presence of multiple and closely located copies of ZFP57 motif variants emerges as a distinct characteristic that is required for the faithful maintenance of repressive epigenetic marks at ICRs and other ZFP57 binding sites. PMID:26481358

  13. The Housekeeping Gene Hypoxanthine Guanine Phosphoribosyltransferase (HPRT) Regulates Multiple Developmental and Metabolic Pathways of Murine Embryonic Stem Cell Neuronal Differentiation

    PubMed Central

    Bader, Joel S.; Friedmann, Theodore

    2013-01-01

    The mechanisms by which mutations of the purinergic housekeeping gene hypoxanthine guanine phosphoribosyltransferase (HPRT) cause the severe neurodevelopmental Lesch Nyhan Disease (LND) are poorly understood. The best recognized neural consequences of HPRT deficiency are defective basal ganglia expression of the neurotransmitter dopamine (DA) and aberrant DA neuronal function. We have reported that HPRT deficiency leads to dysregulated expression of multiple DA-related developmental functions and cellular signaling defects in a variety of HPRT-deficient cells, including human induced pluripotent stem (iPS) cells. We now describe results of gene expression studies during neuronal differentiation of HPRT-deficient murine ESD3 embryonic stem cells and report that HPRT knockdown causes a marked switch from neuronal to glial gene expression and dysregulates expression of Sox2 and its regulator, genes vital for stem cell pluripotency and for the neuronal/glial cell fate decision. In addition, HPRT deficiency dysregulates many cellular functions controlling cell cycle and proliferation mechanisms, RNA metabolism, DNA replication and repair, replication stress, lysosome function, membrane trafficking, signaling pathway for platelet activation (SPPA) multiple neurotransmission systems and sphingolipid, sulfur and glycan metabolism. We propose that the neural aberrations of HPRT deficiency result from combinatorial effects of these multi-system metabolic errors. Since some of these aberrations are also found in forms of Alzheimer's and Huntington's disease, we predict that some of these systems defects play similar neuropathogenic roles in diverse neurodevelopmental and neurodegenerative diseases in common and may therefore provide new experimental opportunities for clarifying pathogenesis and for devising new potential therapeutic targets in developmental and genetic disease. PMID:24130677

  14. Gli Activity Is Critical at Multiple Stages of Embryonic Mammary and Nipple Development

    PubMed Central

    Pinderhughes, Alicia; Koetz, Lisa; Cowin, Pamela

    2013-01-01

    Gli3 is a transcriptional regulator of Hedgehog (Hh) signaling that functions as a repressor (Gli3R) or activator (Gli3A) depending upon cellular context. Previously, we have shown that Gli3R is required for the formation of mammary placodes #3 and #5. Here, we report that this early loss of Gli3 results in abnormal patterning of two critical regulators: Bmp4 and Tbx3, within the presumptive mammary rudiment (MR) #3 zone. We also show that Gli3 loss leads to failure to maintain mammary mesenchyme specification and loss of epithelial Wnt signaling, which impairs the later development of remaining MRs: MR#2 showed profound evagination and ectopic hairs formed within the presumptive areola; MR#4 showed mild invagination defects and males showed inappropriate retention of mammary buds in Gli3xt/xt mice. Importantly, mice genetically manipulated to misactivate Hh signaling displayed the same phenotypic spectrum demonstrating that the repressor function of Gli3R is essential during multiple stages of mammary development. In contrast, positive Hh signaling occurs during nipple development in a mesenchymal cuff around the lactiferous duct and in muscle cells of the nipple sphincter. Collectively, these data show that repression of Hh signaling by Gli3R is critical for early placodal patterning and later mammary mesenchyme specification whereas positive Hh signaling occurs during nipple development. PMID:24260306

  15. Statistical analysis of histopathological endpoints.

    PubMed

    Green, John W; Springer, Timothy A; Saulnier, Amy N; Swintek, Joe

    2014-05-01

    Histopathological assessments of fish from aquatic ecotoxicology studies are being performed with increasing frequency. Aquatic ecotoxicology studies performed for submission to regulatory agencies are usually conducted with multiple subjects (e.g., fish) in each of multiple vessels (replicates) within a water control and within each of several concentrations of a test substance. A number of histopathological endpoints are evaluated in each fish, and a severity score is generally recorded for each endpoint. The severity scores are often recorded using a nonquantitative scale of 0 to 4, with 0 indicating no effect, 1 indicating minimal effect, through 4 for severe effect. Statistical methods often used to analyze these scores suffer from several shortcomings: computing average scores as though scores were quantitative values, considering only the frequency of abnormality while ignoring severity, ignoring any concentration-response trend, and ignoring the possible correlation between responses of individuals within test vessels. A new test, the Rao-Scott Cochran-Armitage by Slices (RSCABS), is proposed that incorporates the replicate vessel experimental design and the biological expectation that the severity of the effect tends to increase with increasing doses or concentrations, while retaining the individual subject scores and taking into account the severity as well as frequency of scores. A power simulation and examples demonstrate the performance of the test. R-based software has been developed to carry out this test and is available free of charge at www.epa.gov/med/Prods_Pubs/rscabs.htm. The SAS-based RSCABS software is available from the first and third authors. PMID:24464649

  16. A U.S. Human Well-being Index (HWBI) for Multiple Scales: Linking Services Provisioning to Human Well-being Endpoints (2000-2010)

    EPA Science Inventory

    objective of this report is to characterize well-being at multiple scales in order to evaluate the relationship of service flows in terms of sustainable well-being. The HWBI results presented represent snapshot assessments for the 2000-2010 time period. Based on the spatial and t...

  17. A multiple endpoint analysis of the effects of chronic exposure to sediment contaminated with Deepwater Horizon oil on juvenile Southern flounder and their associated microbiomes.

    PubMed

    Brown-Peterson, Nancy J; Krasnec, Michelle; Takeshita, Ryan; Ryan, Caitlin N; Griffitt, Kimberly J; Lay, Claire; Mayer, Gregory D; Bayha, Keith M; Hawkins, William E; Lipton, Ian; Morris, Jeffrey; Griffitt, Robert J

    2015-08-01

    Exposure to oiled sediments can negatively impact the health of fish species. Here, we examine the effects of chronic exposure of juvenile southern flounder, Paralichthys lethostigma, to a sediment-oil mixture. Oil:sediment mixtures are persistent over time and can become bioavailable following sediment perturbation or resuspension. Juvenile flounder were exposed for 32 days under controlled laboratory conditions to five concentrations of naturally weathered Macondo MC252 oil mixed into uncontaminated, field-collected sediments. The percent composition of individual polycyclic aromatic hydrocarbons (PAHs) of the weathered oil did not change after mixing with the sediment. Spiked exposure sediments contained 0.04-395mg/kg tPAH50 (sum of 50 individual PAH concentration measurements). Mortality increased with both exposure duration and concentration of sediment-associated PAHs, and flounder exposed to concentrations above 8mg/kg tPAH50 showed significantly reduced growth over the course of the experiment. Evident histopathologic changes were observed in liver and gill tissues of fish exposed to more than 8mg/kg tPAH50. All fish at these concentrations showed hepatic intravascular congestion, macrovesicular hepatic vacoulation, telangiectasia of secondary lamellae, and lamellar epithelial proliferation in gill tissues. Dose-dependent upregulation of Cyp1a expression in liver tissues was observed. Taxonomic analysis of gill and intestinal commensal bacterial assemblages showed that exposure to oiled sediments led to distinct shifts in commensal bacterial population structures. These data show that chronic exposure to environmentally-relevant concentrations of oiled sediments produces adverse effects in flounder at multiple biological levels. PMID:26092636

  18. Biomarkers and correlative endpoints for immunotherapy trials.

    PubMed

    Morse, Michael A; Osada, Takuya; Hobeika, Amy; Patel, Sandip; Lyerly, H Kim

    2013-01-01

    Immunotherapies for lung cancer are reaching phase III clinical trial, but the ultimate success likely will depend on developing biomarkers to guide development and choosing patient populations most likely to benefit. Because the immune response to cancer involves multiple cell types and cytokines, some spatially and temporally separated, it is likely that multiple biomarkers will be required to fully characterize efficacy of the vaccine and predict eventual benefit. Peripheral blood markers of response, such as the ELISPOT assay and cytokine flow cytometry analyses of peripheral blood mononuclear cells following immunotherapy, remain the standard approach, but it is increasingly important to obtain tissue to study the immune response at the site of the tumor. Earlier clinical endpoints such as response rate and progression-free survival do not correlate with overall survival demonstrated for some immunotherapies, suggesting the need to develop other intermediary clinical endpoints. Insofar as all these biomarkers and surrogate endpoints are relevant in multiple malignancies, it may be possible to extrapolate findings to immunotherapy of lung cancer. PMID:23714525

  19. Comparison of biomaterials and extracellular matrices as a culture platform for multiple, independently derived human embryonic stem cell lines.

    PubMed

    Hakala, Heidi; Rajala, Kristiina; Ojala, Marisa; Panula, Sarita; Areva, Sami; Kellomäki, Minna; Suuronen, Riitta; Skottman, Heli

    2009-07-01

    Long-term in vitro culture of undifferentiated human embryonic stem cells (hESCs) traditionally requires a fibroblast feeder cell layer. Using feeder cells in hESC cultures is highly laborious and limits large-scale hESC production for potential application in regenerative medicine. Replacing feeder cells with defined human extracellular matrix (ECM) components or synthetic biomaterials would be ideal for large-scale production of clinical-grade hESCs. We tested and compared different feeder cell-free hESC culture methods based on different human ECM proteins, human and animal sera matrices, and a Matrigel matrix. Also selected biomaterials were tested for feeder cell-free propagation of undifferentiated hESCs. The matrices were tested together with conventional and modified hESC culture media, human foreskin fibroblast-conditioned culture medium, chemically defined medium, TeSR1, and modified TeSR1 media. The results showed the undefined, xenogeneic Matrigel to be a superior matrix for hESC culture compared with the purified human ECM proteins, serum matrices, and the biomaterials tested. A long-term, feeder cell-free culture system was successful on Matrigel in combination with mTeSR1 culture medium, but a xeno-free, fully defined, and reproducible feeder cell-free hESC culture method still remains to be developed. PMID:19132919

  20. Surrogate Endpoints in Suicide Research

    ERIC Educational Resources Information Center

    Wortzel, Hal S.; Gutierrez, Peter M.; Homaifar, Beeta Y.; Breshears, Ryan E.; Harwood, Jeri E.

    2010-01-01

    Surrogate endpoints frequently substitute for rare outcomes in research. The ability to learn about completed suicides by investigating more readily available and proximate outcomes, such as suicide attempts, has obvious appeal. However, concerns with surrogates from the statistical science perspective exist, and mounting evidence from…

  1. Challenges in translating endpoints from trials to observational cohort studies in oncology

    PubMed Central

    Ording, Anne Gulbech; Cronin-Fenton, Deirdre; Ehrenstein, Vera; Lash, Timothy L; Acquavella, John; Rørth, Mikael; Sørensen, Henrik Toft

    2016-01-01

    Clinical trials are considered the gold standard for examining drug efficacy and for approval of new drugs. Medical databases and population surveillance registries are valuable resources for post-approval observational research, which are increasingly used in studies of benefits and risk of new cancer drugs. Here, we address the challenges in translating endpoints from oncology trials to observational studies. Registry-based cohort studies can investigate real-world safety issues – including previously unrecognized concerns – by examining rare endpoints or multiple endpoints at once. In contrast to clinical trials, observational cohort studies typically do not exclude real-world patients from clinical practice, such as old and frail patients with comorbidity. The observational cohort study complements the clinical trial by examining the effectiveness of interventions applied in clinical practice and by providing evidence on long-term clinical outcomes, which are often not feasible to study in a clinical trial. Various endpoints can be included in clinical trials, such as hard endpoints, soft endpoints, surrogate endpoints, and patient-reported endpoints. Each endpoint has it strengths and limitations for use in research studies. Endpoints used in oncology trials are often not applicable in observational cohort studies which are limited by the setting of standard clinical practice and by non-standardized endpoint determination. Observational studies can be more helpful moving research forward if they restrict focus to appropriate and valid endpoints. PMID:27354827

  2. SRC family kinase inhibitors antagonize the toxicity of multiple serotypes of botulinum neurotoxin in human embryonic stem cell-derived motor neurons.

    PubMed

    Kiris, Erkan; Burnett, James C; Nuss, Jonathan E; Wanner, Laura M; Peyser, Brian D; Du, Hao T; Gomba, Glenn Y; Kota, Krishna P; Panchal, Rekha G; Gussio, Rick; Kane, Christopher D; Tessarollo, Lino; Bavari, Sina

    2015-05-01

    Botulinum neurotoxins (BoNTs), the causative agents of botulism, are potent inhibitors of neurotransmitter release from motor neurons. There are currently no drugs to treat BoNT intoxication after the onset of the disease symptoms. In this study, we explored how modulation of key host pathways affects the process of BoNT intoxication in human motor neurons, focusing on Src family kinase (SFK) signaling. Motor neurons derived from human embryonic stem (hES) cells were treated with a panel of SFK inhibitors and intoxicated with BoNT serotypes A, B, or E (which are responsible for >95 % of human botulism cases). Subsequently, it was found that bosutinib, dasatinib, KX2-391, PP1, PP2, Src inhibitor-1, and SU6656 significantly antagonized all three of the serotypes. Furthermore, the data indicated that the treatment of hES-derived motor neurons with multiple SFK inhibitors increased the antagonistic effect synergistically. Mechanistically, the small molecules appear to inhibit BoNTs by targeting host pathways necessary for intoxication and not by directly inhibiting the toxins' proteolytic activity. Importantly, the identified inhibitors are all well-studied with some in clinical trials while others are FDA-approved drugs. Overall, this study emphasizes the importance of targeting host neuronal pathways, rather than the toxin's enzymatic components, to antagonize multiple BoNT serotypes in motor neurons. PMID:25782580

  3. Establishing a group of endpoints to support collective operations without specifying unique identifiers for any endpoints

    DOEpatents

    Archer, Charles J.; Blocksom, Michael A.; Ratterman, Joseph D.; Smith, Brian E.; Xue, Hanghon

    2016-02-02

    A parallel computer executes a number of tasks, each task includes a number of endpoints and the endpoints are configured to support collective operations. In such a parallel computer, establishing a group of endpoints receiving a user specification of a set of endpoints included in a global collection of endpoints, where the user specification defines the set in accordance with a predefined virtual representation of the endpoints, the predefined virtual representation is a data structure setting forth an organization of tasks and endpoints included in the global collection of endpoints and the user specification defines the set of endpoints without a user specification of a particular endpoint; and defining a group of endpoints in dependence upon the predefined virtual representation of the endpoints and the user specification.

  4. Multiple-cardiac-cycle noise reduction in dynamic optical coherence tomography of the embryonic heart and vasculature.

    PubMed

    Bhat, Sandeep; Larina, Irina V; Larin, Kirill V; Dickinson, Mary E; Liebling, Michael

    2009-12-01

    Recent progress in optical coherence tomography (OCT) allows imaging dynamic structures and fluid flow within scattering tissue, such as the beating heart and blood flow in mouse embryos. Accurate representation and analysis of these dynamic behaviors require reducing the noise of the acquired data. Although noise can be reduced by averaging multiple neighboring pixels in space or time, such operations reduce the effective spatial or temporal resolution that can be achieved. We have developed a computational postprocessing technique to restore image sequences of cyclically moving structures that preserves frame rate and spatial resolution. The signal-to-noise ratio (SNR) is improved by combining images from multiple cycles that have been synchronized with a temporally elastic registration procedure. Here we show how this technique can be applied to OCT images of the circulatory system in cultured mouse embryos. Our technique significantly improves the SNR while preserving temporal and spatial resolution. PMID:19953168

  5. Comparative endpoint sensitivity of in vitro estrogen agonist assays.

    PubMed

    Dreier, David A; Connors, Kristin A; Brooks, Bryan W

    2015-07-01

    Environmental and human health implications of endocrine disrupting chemicals (EDCs), particularly xenoestrogens, have received extensive study. In vitro assays are increasingly employed as diagnostic tools to comparatively evaluate chemicals, whole effluent toxicity and surface water quality, and to identify causative EDCs during toxicity identification evaluations. Recently, the U.S. Environmental Protection Agency (USEPA) initiated ToxCast under the Tox21 program to generate novel bioactivity data through high throughput screening. This information is useful for prioritizing chemicals requiring additional hazard information, including endocrine active chemicals. Though multiple in vitro and in vivo techniques have been developed to assess estrogen agonist activity, the relative endpoint sensitivity of these approaches and agreement of their conclusions remain unclear during environmental diagnostic applications. Probabilistic hazard assessment (PHA) approaches, including chemical toxicity distributions (CTD), are useful for understanding the relative sensitivity of endpoints associated with in vitro and in vivo toxicity assays by predicting the likelihood of chemicals eliciting undesirable outcomes at or above environmentally relevant concentrations. In the present study, PHAs were employed to examine the comparative endpoint sensitivity of 16 in vitro assays for estrogen agonist activity using a diverse group of compounds from the USEPA ToxCast dataset. Reporter gene assays were generally observed to possess greater endpoint sensitivity than other assay types, and the Tox21 ERa LUC BG1 Agonist assay was identified as the most sensitive in vitro endpoint for detecting an estrogenic response. When the sensitivity of this most sensitive ToxCast in vitro endpoint was compared to the human MCF-7 cell proliferation assay, a common in vitro model for biomedical and environmental monitoring applications, the ERa LUC BG1 assay was several orders of magnitude less

  6. Evaluation of multiple mechanism-based toxicity endpoints in primary cultured human hepatocytes for the identification of drugs with clinical hepatotoxicity: Results from 152 marketed drugs with known liver injury profiles.

    PubMed

    Zhang, Jie; Doshi, Utkarsh; Suzuki, Ayako; Chang, Ching-Wei; Borlak, Jürgen; Li, Albert P; Tong, Weida

    2016-08-01

    We report here the results of a collaborative research program to develop a robust and reliable in vitro system to allow an accurate definition of the drug-induced liver injury (DILI) potential of new drug entities during drug development. The in vitro hepatotoxic potential of 152 drugs with known DILI profiles were evaluated in primary cultured human hepatocytes with four mechanistically-relevant endpoints: cellular ATP depletion, reactive oxygen species (ROS), glutathione (GSH) depletion, and caspase activation for apoptosis. The drugs, 80 in the testing set and 72 in the validation set, were classified based on serious clinical/regulatory outcomes as defined by reported acute liver failure, black-box warning, and/or withdrawal. The drugs were further sub-categorized for dominant types of liver injury. Logistic regression models were performed to calculate the area under the receiver operating characteristics curve (AUROC) and to evaluate the prediction potential of the selected endpoints for serious clinical/regulatory outcomes. The ROS/ATP ratio was found to yield an excellent AUROC in both the testing (0.8989, P < 0.0001) and validation set (0.8545, P < 0.0001), and was found to distinguish drugs associated with severe from non-severe DILI cases (p < 0.0001). The results suggest that evaluation of drugs in primary human hepatocytes using the ROS/ATP ratio endpoint may aid the definition of their potential to cause severe DILI. PMID:26581450

  7. Pathophysiological Progression Model for Selected Toxicological Endpoints

    EPA Science Inventory

    The existing continuum paradigms are effective models to organize toxicological data associated with endpoints used in human health assessments. A compendium of endpoints characterized along a pathophysiological continuum would serve to: weigh the relative importance of effects o...

  8. Biomarkers and Surrogate Endpoints In Clinical Trials

    PubMed Central

    Fleming, Thomas R.; Powers, John H

    2012-01-01

    One of the most important considerations in designing clinical trials is the choice of outcome measures. These outcome measures could be clinically meaningful endpoints that are direct measures of how patients feel, function and survive. Alternatively, indirect measures, such as biomarkers that include physical signs of disease, laboratory measures and radiological tests, often are considered as replacement endpoints or “surrogates” for clinically meaningful endpoints. We discuss the definitions of clinically meaningful endpoints and surrogate endpoints, and provide examples from recent clinical trials. We provide insight into why indirect measures such as biomarkers may fail to provide reliable evidence about the benefit-to-risk profile of interventions. We also discuss the nature of evidence that is important in assessing whether treatment effects on a biomarker reliably predict effects on a clinically meaningful endpoint, and provide insights into why this reliability is specific to the context of use of the biomarker. . PMID:22711298

  9. Embryonic hematopoiesis.

    PubMed

    Golub, Rachel; Cumano, Ana

    2013-12-01

    Blood cells are continually produced from a pool of progenitors that derive from hematopoietic stem cells (HSCs). In vertebrates, the hematopoietic system develops from two distinct waves or generation of precursors. The first wave occurs in the yolk sac, in mammals or equivalent embryonic structure, and produces nucleated primitive erythrocytes that provide the embryo with the first oxygen transporter and are, therefore, essential for the viability of the embryo. The yolk sac also produces myeloid cells that migrate to the central nervous system and to the skin to form the microglia and skin specific macrophages, the Langerhans cells. The second wave occurs in the dorsal aorta and produces multipotential hematopoietic progenitors. These cells are generated once in the lifetime from mesoderm derivatives closely related to endothelial cells, during a short period of embryonic development. Newly generated cells do not reconstitute the hematopoietic compartment of conventional recipients; therefore, they are designated as immature or pre-HSCs. They undergo maturation into adult HSCs in the aorta or in the fetal liver accompanied by the expression of MHC class I, CD45, CD150, Sca-1 and the absence of CD48. Differentiation of HSCs first occurs in the fetal liver, giving rise to mature blood cells. HSCs also expand in the fetal liver, and in a short time period (four days in the mouse embryo), they increase over 40-fold. HSCs and progenitor cells exit the fetal liver and colonize the spleen, where differentiation to the myeloid lineage and particular lymphoid subsets is favored. PMID:24041595

  10. Exact relativistic {beta} decay endpoint spectrum

    SciTech Connect

    Masood, S. S.; Nasri, S.; Schechter, J.; Tortola, M. A.; Valle, J. W. F.

    2007-10-15

    The exact relativistic form for the {beta} decay endpoint spectrum is derived and presented in a simple factorized form. We show that our exact formula can be well approximated to yield the endpoint form used in the fit method of the KATRIN Collaboration. We also discuss the three-neutrino case and how information from neutrino oscillation experiments may be useful in analyzing future {beta} decay endpoint experiments.

  11. Evaluating endocrine endpoints relative to reproductive success in Japanese quail exposed to estrogenic chemicals [poster

    USGS Publications Warehouse

    Henry, P.F.P.; Russek-Cohen, E.; Casey, C.S.; Abdelnabi, M.A.; Ottinger, M.A.

    2000-01-01

    The standard US EPA guidelines for avian reproductive testing may not be sufficiently sensitive to detect effects of sublethal and chronic exposure to endocrine disrupting toxins. There is a need to evaluate endocrine endpoints as potential markers for contaminant effects, and to determine their effectiveness and sensitivity when applied to wildlife. To this end, a three generational test was conducted using the Japanese quail (Coturnix japonica) and a proven estrogenic PCB. Birds were exposed during embryonic development via maternal deposition and/or direct egg injection at day 4. Standard measures of reproductive success and productivity used in toxicological studies, as well as multiple measures of physiological and behavioral responses used in endocrine studies were collected. Long term effects on growth and apparent development were similar between treated and control offspring. Fertility of treated eggs decreased from 75%+ 4.4 (x + se) for P1, to 59% + 12.5 for F1 and 54% + 14.2 for F2. All paired control birds mated to produce viable eggs, whereas 27 % of the F1 and 41 % of the F2 treated pairs failed to produce at least 1 viable egg. Although some decreases in productivity can be related to direct toxic exposure, the response from one generation to the next was not linear with treatment, indicating a potential effect from behavioral or other endocrine alterations.

  12. ENDPOINTS OF SPERMATOXICITY IN THE RAT AFTER ACUTE EXPOSURES TO FOURTEEN MALE REPRODUCTIVE TOXICANTS

    EPA Science Inventory

    Multiple endpoints of spermatotoxicity in short in vivo tests were investigated in several chemicals which produce minimal to severe subchronic reproductive effects. Six chemicals (boric acid, dinoseb, 2,5-hexanedione, methoxychlor, metronidazole, ornidazole) produced spermatotox...

  13. Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) assay

    EPA Science Inventory

    The Embryonic Stem Cell Test (EST) is an assay which evaluates xenobiotic-induced effects using three endpoints: mouse embryonic stem cell (mESC) differentiation, mESC viability, and 3T3-cell viability. Our research goal was to develop an improved high-throughput assay by establi...

  14. [Immunological surrogate endpoints to evaluate vaccine efficacy].

    PubMed

    Jin, Pengfei; Li, Jingxin; Zhou, Yang; Zhu, Fengcai

    2015-12-01

    An immunological surrogate endpoints is a vaccine-induced immune response (either humoral or cellular immune) that predicts protection against clinical endpoints (infection or disease), and can be used to evaluate vaccine efficacy in clinical vaccine trials. Compared with field efficacy trials observing clinical endpoints, immunological vaccine trials could reduce the sample size or shorten the duration of a trial, which promote the license and development of new candidate vaccines. For these reasons, establishing immunological surrogate endpoints is one of 14 Grand Challenges of Global Health of the National Institutes of Health (NIH) and the Bill and Melinda Gates Foundation. From two parts of definition and statistical methods for evaluation of surrogate endpoints, this review provides a more comprehensive description. PMID:26887309

  15. Fallback tests for co-primary endpoints.

    PubMed

    Ristl, Robin; Frommlet, Florian; Koch, Armin; Posch, Martin

    2016-07-20

    When efficacy of a treatment is measured by co-primary endpoints, efficacy is claimed only if for each endpoint an individual statistical test is significant at level α. While such a strategy controls the family-wise type I error rate (FWER), it is often strictly conservative and allows for no inference if not all null hypotheses can be rejected. In this paper, we investigate fallback tests, which are defined as uniform improvements of the classical test for co-primary endpoints. They reject whenever the classical test rejects but allow for inference also in settings where only a subset of endpoints show a significant effect. Similarly to the fallback tests for hierarchical testing procedures, these fallback tests for co-primary endpoints allow one to continue testing even if the primary objective of the trial was not met. We propose examples of fallback tests for two and three co-primary endpoints that control the FWER in the strong sense under the assumption of multivariate normal test statistics with arbitrary correlation matrix and investigate their power in a simulation study. The fallback procedures for co-primary endpoints are illustrated with a clinical trial in a rare disease and a diagnostic trial. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. PMID:26919166

  16. Multi-Toxic Endpoints of the Foodborne Mycotoxins in Nematode Caenorhabditis elegans

    PubMed Central

    Yang, Zhendong; Xue, Kathy S.; Sun, Xiulan; Tang, Lili; Wang, Jia-Sheng

    2015-01-01

    Aflatoxins B1 (AFB1), deoxynivalenol (DON), fumonisin B1 (FB1), T-2 toxin (T-2), and zearalenone (ZEA) are the major foodborne mycotoxins of public health concerns. In the present study, the multiple toxic endpoints of these naturally-occurring mycotoxins were evaluated in Caenorhabditis elegans model for their lethality, toxic effects on growth and reproduction, as well as influence on lifespan. We found that the lethality endpoint was more sensitive for T-2 toxicity with the EC50 at 1.38 mg/L, the growth endpoint was relatively sensitive for AFB1 toxic effects, and the reproduction endpoint was more sensitive for toxicities of AFB1, FB1, and ZEA. Moreover, the lifespan endpoint was sensitive to toxic effects of all five tested mycotoxins. Data obtained from this study may serve as an important contribution to knowledge on assessment of mycotoxin toxic effects, especially for assessing developmental and reproductive toxic effects, using the C. elegans model. PMID:26633509

  17. Multi-Toxic Endpoints of the Foodborne Mycotoxins in Nematode Caenorhabditis elegans.

    PubMed

    Yang, Zhendong; Xue, Kathy S; Sun, Xiulan; Tang, Lili; Wang, Jia-Sheng

    2015-12-01

    Aflatoxins B₁ (AFB₁), deoxynivalenol (DON), fumonisin B₁ (FB₁), T-2 toxin (T-2), and zearalenone (ZEA) are the major foodborne mycotoxins of public health concerns. In the present study, the multiple toxic endpoints of these naturally-occurring mycotoxins were evaluated in Caenorhabditis elegans model for their lethality, toxic effects on growth and reproduction, as well as influence on lifespan. We found that the lethality endpoint was more sensitive for T-2 toxicity with the EC50 at 1.38 mg/L, the growth endpoint was relatively sensitive for AFB₁ toxic effects, and the reproduction endpoint was more sensitive for toxicities of AFB₁, FB₁, and ZEA. Moreover, the lifespan endpoint was sensitive to toxic effects of all five tested mycotoxins. Data obtained from this study may serve as an important contribution to knowledge on assessment of mycotoxin toxic effects, especially for assessing developmental and reproductive toxic effects, using the C. elegans model. PMID:26633509

  18. Automatic endpoint detection to support the systematic review process.

    PubMed

    Blake, Catherine; Lucic, Ana

    2015-08-01

    Preparing a systematic review can take hundreds of hours to complete, but the process of reconciling different results from multiple studies is the bedrock of evidence-based medicine. We introduce a two-step approach to automatically extract three facets - two entities (the agent and object) and the way in which the entities are compared (the endpoint) - from direct comparative sentences in full-text articles. The system does not require a user to predefine entities in advance and thus can be used in domains where entity recognition is difficult or unavailable. As with a systematic review, the tabular summary produced using the automatically extracted facets shows how experimental results differ between studies. Experiments were conducted using a collection of more than 2million sentences from three journals Diabetes, Carcinogenesis and Endocrinology and two machine learning algorithms, support vector machines (SVM) and a general linear model (GLM). F1 and accuracy measures for the SVM and GLM differed by only 0.01 across all three comparison facets in a randomly selected set of test sentences. The system achieved the best performance of 92% for objects, whereas the accuracy for both agent and endpoints was 73%. F1 scores were higher for objects (0.77) than for endpoints (0.51) or agents (0.47). A situated evaluation of Metformin, a drug to treat diabetes, showed system accuracy of 95%, 83% and 79% for the object, endpoint and agent respectively. The situated evaluation had higher F1 scores of 0.88, 0.64 and 0.62 for object, endpoint, and agent respectively. On average, only 5.31% of the sentences in a full-text article are direct comparisons, but the tabular summaries suggest that these sentences provide a rich source of currently underutilized information that can be used to accelerate the systematic review process and identify gaps where future research should be focused. PMID:26003938

  19. Dynamic expression of tyrosine hydroxylase mRNA and protein in neurons of the striatum and amygdala of mice, and experimental evidence of their multiple embryonic origin.

    PubMed

    Bupesh, Munisamy; Vicario, Alba; Abellán, Antonio; Desfilis, Ester; Medina, Loreta

    2014-05-01

    Emotional and motivational dysfunctions observed in Parkinson's disease, schizophrenia, and drug addiction are associated to an alteration of the mesocortical and mesolimbic dopaminergic pathways, which include axons projecting to the prefrontal cortex, the ventral striatum, and the amygdala. Subpopulations of catecholaminergic neurons have been described in the cortex and striatum of several mammals, but the presence of such cells in the adult amygdala is unclear in murine rodents, and in other rodents appears to show variations depending on the species. Moreover, the embryonic origin of telencephalic tyrosine hydroxylase (TH) cells is unknown, which is essential for trying to understand aspects of their evolution, distribution and function. Herein we investigated the expression of TH mRNA and protein in cells of the striatum and amygdala of developing and adult mice, and analyzed the embryonic origin of such cells using in vitro migration assays. Our results showed the presence of TH mRNA and protein expressing cells in the striatum (including nucleus accumbens), central and medial extended amygdala during development, which are persistent in adulthood although they are less numerous, generally show weak mRNA expression, and some appear to lack the protein. Fate mapping analysis showed that these cells include at least two subpopulations with different embryonic origin in either the commissural preoptic area of the subpallium or the supraopto-paraventricular domain of the alar hypothalamus. These data are important for future studies trying to understand the role of catecholamines in modulation of emotion, motivation, and reward. PMID:23479178

  20. Comparing Laboratory and Field Measured Bioaccumulation Endpoints

    EPA Science Inventory

    The report presents an approach that allows comparisons of all laboratory and field bioaccumulation endpoints measurements. The approach will enable the inclusion of large amounts of field data into evaluations of bioaccumulation potential for legacy chemicals. Currently, these...

  1. Establishing a group of endpoints in a parallel computer

    DOEpatents

    Archer, Charles J.; Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.; Xue, Hanhong

    2016-02-02

    A parallel computer executes a number of tasks, each task includes a number of endpoints and the endpoints are configured to support collective operations. In such a parallel computer, establishing a group of endpoints receiving a user specification of a set of endpoints included in a global collection of endpoints, where the user specification defines the set in accordance with a predefined virtual representation of the endpoints, the predefined virtual representation is a data structure setting forth an organization of tasks and endpoints included in the global collection of endpoints and the user specification defines the set of endpoints without a user specification of a particular endpoint; and defining a group of endpoints in dependence upon the predefined virtual representation of the endpoints and the user specification.

  2. Ovarian cancer clinical trial endpoints: Society of Gynecologic Oncology white paper

    PubMed Central

    Herzog, Thomas J.; Armstrong, Deborah K.; Brady, Mark F.; Coleman, Robert L.; Einstein, Mark H.; Monk, Bradley J.; Mannel, Robert S.; Thigpen, J. Tate; Umpierre, Sharee A.; Villella, Jeannine A.; Alvarez, Ronald D.

    2015-01-01

    Objective To explore the value of multiple clinical endpoints in the unique setting of ovarian cancer. Methods A clinical trial workgroup was established by the Society of Gynecologic Oncology to develop a consensus statement via multiple conference calls, meetings and white paper drafts. Results Clinical trial endpoints have profound effects on late phase clinical trial design, result interpretation, drug development, and regulatory approval of therapeutics. Selection of the optimal clinical trial endpoint is particularly provocative in ovarian cancer where long overall survival (OS) is observed. The lack of new regulatory approvals and the lack of harmony between regulatory bodies globally for ovarian cancer therapeutics are of concern. The advantages and disadvantages of the numerous endpoints available are herein discussed within the unique context of ovarian cancer where both crossover and post-progression therapies potentially uncouple surrogacy between progression-free survival (PFS) and OS, the two most widely supported and utilized endpoints. The roles of patient reported outcomes (PRO) and health related quality of life (HRQoL) are discussed, but even these widely supported parameters are affected by the unique characteristics of ovarian cancer where a significant percentage of patients may be asymptomatic. Original data regarding the endpoint preferences of ovarian cancer advocates is presented. Conclusions Endpoint selection in ovarian cancer clinical trials should reflect the impact on disease burden and unique characteristics of the treatment cohort while reflecting true patient benefit. Both OS and PFS have led to regulatory approvals and are clinically important. OS remains the most objective and accepted endpoint because it is least vulnerable to bias; however, the feasibility of OS in ovarian cancer is compromised by the requirement for large trial size, prolonged time-line for final analysis, and potential for unintended loss of treatment effect

  3. Enabling communication concurrency through flexible MPI endpoints

    DOE PAGESBeta

    Dinan, James; Grant, Ryan E.; Balaji, Pavan; Goodell, David; Miller, Douglas; Snir, Marc; Thakur, Rajeev

    2014-09-23

    MPI defines a one-to-one relationship between MPI processes and ranks. This model captures many use cases effectively; however, it also limits communication concurrency and interoperability between MPI and programming models that utilize threads. Our paper describes the MPI endpoints extension, which relaxes the longstanding one-to-one relationship between MPI processes and ranks. Using endpoints, an MPI implementation can map separate communication contexts to threads, allowing them to drive communication independently. Also, endpoints enable threads to be addressable in MPI operations, enhancing interoperability between MPI and other programming models. Furthermore, these characteristics are illustrated through several examples and an empirical study thatmore » contrasts current multithreaded communication performance with the need for high degrees of communication concurrency to achieve peak communication performance.« less

  4. Enabling communication concurrency through flexible MPI endpoints

    SciTech Connect

    Dinan, James; Grant, Ryan E.; Balaji, Pavan; Goodell, David; Miller, Douglas; Snir, Marc; Thakur, Rajeev

    2014-09-23

    MPI defines a one-to-one relationship between MPI processes and ranks. This model captures many use cases effectively; however, it also limits communication concurrency and interoperability between MPI and programming models that utilize threads. Our paper describes the MPI endpoints extension, which relaxes the longstanding one-to-one relationship between MPI processes and ranks. Using endpoints, an MPI implementation can map separate communication contexts to threads, allowing them to drive communication independently. Also, endpoints enable threads to be addressable in MPI operations, enhancing interoperability between MPI and other programming models. Furthermore, these characteristics are illustrated through several examples and an empirical study that contrasts current multithreaded communication performance with the need for high degrees of communication concurrency to achieve peak communication performance.

  5. Sublethal Toxicity Endpoints of Heavy Metals to the Nematode Caenorhabditis elegans.

    PubMed

    Jiang, Ying; Chen, Jiandong; Wu, Yue; Wang, Qiang; Li, Huixin

    2016-01-01

    Caenorhabditis elegans, a free-living nematode, is commonly used as a model organism in ecotoxicological studies. The current literatures have provided useful insight into the relative sensitivity of several endpoints, but few direct comparisons of multiple endpoints under a common set of experimental conditions. The objective of this study was to determine appropriate sublethal endpoints to develop an ecotoxicity screening and monitoring system. C. elegans was applied to explore the sublethal toxicity of four heavy metals (copper, zinc, cadmium and chromium). Two physiological endpoints (growth and reproduction), three behavioral endpoints (head thrash frequency, body bend frequency and feeding) and two enzymatic endpoints (acetylcholine esterase [AChE] and superoxide dismutase [SOD]) were selected for the assessment of heavy metal toxicity. The squared correlation coefficients (R2) between the responses observed and fitted by Logit function were higher than 0.90 and the RMSE were lower than 0.10, indicating a good significance statistically. There was no significant difference among the half effect concentration (EC50) endpoints in physiological and behavioral effects of the four heavy metals, indicating similar sensitivity of physiological and behavioral effects. AChE enzyme was more sensitive to copper, zinc, and cadmium than to other physiological and behavioral effects, and SOD enzyme was most sensitive to chromium. The EC50 of copper, zinc, and cadmium, to the AChE enzyme in the nematodes were 0.68 mg/L, 2.76 mg/L, and 0.92 mg/L respectively and the EC50 of chromium to the SOD enzyme in the nematode was 1.58 mg/L. The results of this study showed that there was a good concentration-response relationship between all four heavy metals and the sublethal toxicity effects to C. elegans. Considering these sublethal endpoints in terms of simplicity, accuracy, repeatability and costs of the experiments, feeding is the relatively ideal sublethal toxicity endpoint of

  6. Sublethal Toxicity Endpoints of Heavy Metals to the Nematode Caenorhabditis elegans

    PubMed Central

    Wu, Yue; Wang, Qiang; Li, Huixin

    2016-01-01

    Caenorhabditis elegans, a free-living nematode, is commonly used as a model organism in ecotoxicological studies. The current literatures have provided useful insight into the relative sensitivity of several endpoints, but few direct comparisons of multiple endpoints under a common set of experimental conditions. The objective of this study was to determine appropriate sublethal endpoints to develop an ecotoxicity screening and monitoring system. C. elegans was applied to explore the sublethal toxicity of four heavy metals (copper, zinc, cadmium and chromium). Two physiological endpoints (growth and reproduction), three behavioral endpoints (head thrash frequency, body bend frequency and feeding) and two enzymatic endpoints (acetylcholine esterase [AChE] and superoxide dismutase [SOD]) were selected for the assessment of heavy metal toxicity. The squared correlation coefficients (R2) between the responses observed and fitted by Logit function were higher than 0.90 and the RMSE were lower than 0.10, indicating a good significance statistically. There was no significant difference among the half effect concentration (EC50) endpoints in physiological and behavioral effects of the four heavy metals, indicating similar sensitivity of physiological and behavioral effects. AChE enzyme was more sensitive to copper, zinc, and cadmium than to other physiological and behavioral effects, and SOD enzyme was most sensitive to chromium. The EC50 of copper, zinc, and cadmium, to the AChE enzyme in the nematodes were 0.68 mg/L, 2.76 mg/L, and 0.92 mg/L respectively and the EC50 of chromium to the SOD enzyme in the nematode was 1.58 mg/L. The results of this study showed that there was a good concentration-response relationship between all four heavy metals and the sublethal toxicity effects to C. elegans. Considering these sublethal endpoints in terms of simplicity, accuracy, repeatability and costs of the experiments, feeding is the relatively ideal sublethal toxicity endpoint of

  7. LIFE CYCLE IMPACT ASSESSMENT - MIDPOINTS VS. ENDPOINTS

    EPA Science Inventory

    The question of whether to use midpoints or endpoints or both in an LCIA framework is often dependent upon the goal and scope and the decision that is being supported by the LCIA. LCIAs for Enlightenment may not require an aggregation of impact categories and may be most useful ...

  8. IPF clinical trial design and endpoints

    PubMed Central

    Nathan, Steven D.; Meyer, Keith C.

    2014-01-01

    Purpose of review There remains a dire need for therapies that impact the clinical course of patients with idiopathic pulmonary fibrosis (IPF). Indeed, there is a surge of interest in IPF therapeutics, with many candidate agents in various stages of development. Optimal design and implementation of the appropriate prospective clinical trials are essential to demonstrate clinical efficacy of promising drugs for the treatment of IPF. A key element in the success of such clinical trials is the choice of the best endpoint(s) to match the design of the study. Recent findings Although the results of many IPF clinical trials have been disappointing, these trials have provided valuable insights into the epidemiology and natural history of the disease and have sparked debate into the best clinical trial designs and endpoints. Summary This review will discuss the various clinical trial endpoints that have been used or proposed with a focus on their potential utility, as well as possible pitfalls that investigators should consider in the design of such studies. Video abstract http://links.lww.com/COPM/A13 PMID:25022315

  9. Shift endpoint trace selection algorithm and wavelet analysis to detect the endpoint using optical emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Ben Zakour, Sihem; Taleb, Hassen

    2016-06-01

    Endpoint detection (EPD) is very important undertaking on the side of getting a good understanding and figuring out if a plasma etching process is done on the right way. It is truly a crucial part of supplying repeatable effects in every single wafer. When the film to be etched has been completely erased, the endpoint is reached. In order to ensure the desired device performance on the produced integrated circuit, many sensors are used to detect the endpoint, such as the optical, electrical, acoustical/vibrational, thermal, and frictional. But, except the optical sensor, the other ones show their weaknesses due to the environmental conditions which affect the exactness of reaching endpoint. Unfortunately, some exposed area to the film to be etched is very low (<0.5%), reflecting low signal and showing the incapacity of the traditional endpoint detection method to determine the wind-up of the etch process. This work has provided a means to improve the endpoint detection sensitivity by collecting a huge numbers of full spectral data containing 1201 spectra for each run, then a new unsophisticated algorithm is proposed to select the important endpoint traces named shift endpoint trace selection (SETS). Then, a sensitivity analysis of linear methods named principal component analysis (PCA) and factor analysis (FA), and the nonlinear method called wavelet analysis (WA) for both approximation and details will be studied to compare performances of the methods mentioned above. The signal to noise ratio (SNR) is not only computed based on the main etch (ME) period but also the over etch (OE) period. Moreover, a new unused statistic for EPD, coefficient of variation (CV), is proposed to reach the endpoint in plasma etches process.

  10. A specific endpoint assay for ubiquitin.

    PubMed Central

    Rose, I A; Warms, J V

    1987-01-01

    Simple endpoint assays for free ubiquitin (Ub) and for the Ub-activating enzyme are described. The method for measuring Ub makes use of the reaction of iodoacetamide-treated Ub-activating enzyme (E): [3H]ATP + Ub + E----E X [3H]AMP-Ub + PPi and PPi----2Pi (in the presence of pyrophosphatase). The Ub is then measured by determining the acid-insoluble radioactivity. The reaction is accompanied by a slow enzyme-catalyzed hydrolysis of the complex to AMP plus Ub. The presence of ubiquitin-activating enzyme in excess of Ub by approximately equal to 0.1 microM assures that the steady state will be close to the endpoint for total Ub. A preparation of the activating enzyme from human erythrocytes that does not depend on affinity chromatography is described. Several applications of the assay are presented. PMID:3031643

  11. Protein patterns as endpoints in environmental remediation

    SciTech Connect

    Bradley, B.; Brown, D.

    1995-12-31

    Biological endpoints can complement chemical analyses in monitoring environmental remediation. In some cases the levels of chemical detection are so low that the costs of clean-up to no detection would be prohibitive. And chemical tests do not indicate the availability of the contaminants to the biota. On the other hand many if not most biological tests lack specificity. The authors have investigated a protein expression assay to establish an endpoint for clean-up of sulfur mustard and breakdown products. Earthworms (Lumbricus terrestris) were exposed to sulfur mustard (SM), a breakdown product thiodiethanol (TDE), and ethylene glycol, the solvent for the two chemicals. Tissue from the lining of the coelomic cavity was taken from each of 6 worms in each treatment class. Soluble proteins were extracted and separated on one and two-dimensional (1D and 2D) gels. The 1 D gels showed no difference by eye but the patterns from control and solvent control worms on 2D gels differed from those of worms exposed to TDE and SM. The 1D gel data were digitized and analyzed by pattern recognition using artificial neural networks. The protein patterns under the two treatments and the two controls were learned in one set of data and successfully recognized in a second. This indicated that what was learned was useful in recognizing patterns induced by SM and TDE. Thus a possible endpoint for remediation would be the protein pattern at no effect levels of chemicals of interest.

  12. Elevated Nuclear and Cytoplasmic FTY720-Phosphate in Mouse Embryonic Fibroblasts Suggests the Potential for Multiple Mechanisms in FTY720-Induced Neural Tube Defects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    FTY720 (fingolimod) is an FDA-approved drug to treat relapsing remitting multiple sclerosis. FTY720 treatment in pregnant inbred LM/Bc mice results in approximately 60% of embryos having a neural tube defect (NTD). Sphingosine kinases (Sphk1, Sphk2) phosphorylate FTY720 in vivo to form the bioactive...

  13. Some Endpoint Results for β-Generalized Weak Contractive Multifunctions

    PubMed Central

    Alikhani, H.; Gopal, D.; Miandaragh, M. A.; Rezapour, Sh.; Shahzad, N.

    2013-01-01

    We introduce β-generalized weak contractive multifunctions and give some results about endpoints of the multifunctions. Also, we give some results about role of a point in the existence of endpoints. PMID:24348197

  14. Ecosystem Services as Assessment Endpoints in Ecological Risk Assessment

    EPA Science Inventory

    The focus of ecological risk assessment (ERA) is on assessment endpoints, explicit expressions of environmental values to be protected. Traditionally, the ecological entities identified in assessment endpoints have been components of ecosystems deemed by risk assessors to be impo...

  15. The Role of Ecological Endpoints in Watershed Management

    EPA Science Inventory

    Landscape change and pollution in watersheds affect ecological endpoints in receiving water bodies. Therefore, these endpoints are useful in watershed management. Fish and benthic macro invertebrates are often used as endpoints, since they are easily measured in the field and int...

  16. Evaluation of a Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity (ACDC) assay (SOT)

    EPA Science Inventory

    The Embryonic Stem Cell Test (EST) has been used to evaluate the effects of xenobiotics using three endpoints, stem cell differentiation, stem cell viability and 3T3-cell viability. Our research goal is to establish amodel system that would evaluate chemical effects using a singl...

  17. Helicopter EMS: Research Endpoints and Potential Benefits

    PubMed Central

    Thomas, Stephen H.; Arthur, Annette O.

    2012-01-01

    Patients, EMS systems, and healthcare regions benefit from Helicopter EMS (HEMS) utilization. This article discusses these benefits in terms of specific endpoints utilized in research projects. The endpoint of interest, be it primary, secondary, or surrogate, is important to understand in the deployment of HEMS resources or in planning further HEMS outcomes research. The most important outcomes are those which show potential benefits to the patients, such as functional survival, pain relief, and earlier ALS care. Case reports are also important “outcomes” publications. The benefits of HEMS in the rural setting is the ability to provide timely access to Level I or Level II trauma centers and in nontrauma, interfacility transport of cardiac, stroke, and even sepsis patients. Many HEMS crews have pharmacologic and procedural capabilities that bring a different level of care to a trauma scene or small referring hospital, especially in the rural setting. Regional healthcare and EMS system's benefit from HEMS by their capability to extend the advanced level of care throughout a region, provide a “backup” for areas with limited ALS coverage, minimize transport times, make available direct transport to specialized centers, and offer flexibility of transport in overloaded hospital systems. PMID:22203905

  18. Strategies and Endpoints of Antifibrotic Drug Trials

    PubMed Central

    Torok, Natalie; Dranoff, Jonathan A.; Schuppan, Detlef; Friedman, Scott L.

    2015-01-01

    There is an urgent need to develop antifibrotic therapies for chronic liver disease, and to clarify which endpoints in antifibrotic trials will be acceptable to regulatory agencies. AASLD sponsored an endpoints conference to help accelerate the efficient testing of antifibrotic agents and to develop recommendations on clinical trial design for liver fibrosis. In this review we summarize the salient and novel elements of this conference and provide directions for future clinical trial design. The paper follows the structure of the conference and is organized into five areas: I) Antifibrotic trial design; II) Preclinical proof of concept studies; III) Pharmacologic targets: rationale and lessons to learn; IV) Rational drug design and development; V) Consensus and recommendations on design of clinical trials in liver fibrosis. Expert overviews and collaborative discussions helped to summarize the key unmet needs and directions for the future, including: 1) Greater clarification of at-risk populations and study groups; 2) Standardization of all elements of drug discovery and testing; 3) Standardization of clinical trial approaches; 4) Accelerated development of improved non-invasive markers; 5) Need for exploration of potential off-target toxicities of future antifibrotic drugs. PMID:25626988

  19. Population growth rate determinants for Arbacia: Evaluating ecological relevance of toxicity test endpoints

    SciTech Connect

    Nacci, D.; Gleason, T.; Munns, W.R. Jr.

    1995-12-31

    A population dynamics model for the sea urchin, Arbacia punctulata, was recently developed incorporating life stage endpoints frequently measured in acute and chronic toxicity studies. Model elasticity analysis was used to demonstrate that population growth rate was influenced most by adult survival and least by early life stage success, calling into question the ecological relevance of results from standardized Arbacia fertilization and larval development toxicity tests. Two approaches were used to continue this evaluation. Actual and hypothetical dose-response curves for toxicant exposures over multiple life stages were used to evaluate contributions to population growth rate of stage-specific toxicant effects. Additionally, relationships between critical life stages were developed from laboratory data for Arbacia. The results of this analysis underscore the importance of understanding both endpoint sensitivity to toxicants and sensitivity of population growth rate to test endpoints in determining the ecological relevance of toxicity tests results.

  20. Review of meta-analyses evaluating surrogate endpoints for overall survival in oncology

    PubMed Central

    Sherrill, Beth; Kaye, James A; Sandin, Rickard; Cappelleri, Joseph C; Chen, Connie

    2012-01-01

    Overall survival (OS) is the gold standard in measuring the treatment effect of new drug therapies for cancer. However, practical factors may preclude the collection of unconfounded OS data, and surrogate endpoints are often used instead. Meta-analyses have been widely used for the validation of surrogate endpoints, specifically in oncology. This research reviewed published meta-analyses on the types of surrogate measures used in oncology studies and examined the extent of correlation between surrogate endpoints and OS for different cancer types. A search was conducted in October 2010 to compile available published evidence in the English language for the validation of disease progression-related endpoints as surrogates of OS, based on meta-analyses. We summarize published meta-analyses that quantified the correlation between progression-based endpoints and OS for multiple advanced solid-tumor types. We also discuss issues that affect the interpretation of these findings. Progression-free survival is the most commonly used surrogate measure in studies of advanced solid tumors, and correlation with OS is reported for a limited number of cancer types. Given the increased use of crossover in trials and the availability of second-/third-line treatment options available to patients after progression, it will become increasingly more difficult to establish correlation between effects on progression-free survival and OS in additional tumor types. PMID:23109809

  1. Expression of multiple Sox genes through embryonic development in the ctenophore Mnemiopsis leidyi is spatially restricted to zones of cell proliferation

    PubMed Central

    2014-01-01

    Background The Sox genes, a family of transcription factors characterized by the presence of a high mobility group (HMG) box domain, are among the central groups of developmental regulators in the animal kingdom. They are indispensable in progenitor cell fate determination, and various Sox family members are involved in managing the critical balance between stem cells and differentiating cells. There are 20 mammalian Sox genes that are divided into five major groups (B, C, D, E, and F). True Sox genes have been identified in all animal lineages but not outside Metazoa, indicating that this gene family arose at the origin of the animals. Whole-genome sequencing of the lobate ctenophore Mnemiopsis leidyi allowed us to examine the full complement and expression of the Sox gene family in this early-branching animal lineage. Results Our phylogenetic analyses of the Sox gene family were generally in agreement with previous studies and placed five of the six Mnemiopsis Sox genes into one of the major Sox groups: SoxB (MleSox1), SoxC (MleSox2), SoxE (MleSox3, MleSox4), and SoxF (MleSox5), with one unclassified gene (MleSox6). We investigated the expression of five out of six Mnemiopsis Sox genes during early development. Expression patterns determined through in situ hybridization generally revealed spatially restricted Sox expression patterns in somatic cells within zones of cell proliferation, as determined by EdU staining. These zones were located in the apical sense organ, upper tentacle bulbs, and developing comb rows in Mnemiopsis, and coincide with similar zones identified in the cydippid ctenophore Pleurobrachia. Conclusions Our results are consistent with the established role of multiple Sox genes in the maintenance of stem cell pools. Both similarities and differences in juvenile cydippid stage expression patterns between Mnemiopsis Sox genes and their orthologs from Pleurobrachia highlight the importance of using multiple species to characterize the evolution of

  2. End-Point Detection With Laser Interferometry

    NASA Astrophysics Data System (ADS)

    Busta, Heinz H.

    1981-04-01

    A laser interferometric method was developed to detect end-of-etching of materials such as doped and undoped polysilicon, Si3N4, Si02 and metals used during different stages of IC and thin film device processing. For metal etching, a detector trace of constant magnitude is obtained until the underlying layers are exposed. At this point, a step change in re-flectivity occurs, signaling the end-point. For the other above mentioned films, a sinu-soidal waveform is obtained which changes its frequency once the film of interest is etched and the underlying layers become exposed. The method is applicable to all of the dry etch-ing processes and will be illustrated in some detail for polysilicon and silicon nitride etching applications using a barrel-type plasma reactor.

  3. Neoadjuvant endocrine therapy: Patient selection, treatment duration and surrogate endpoints.

    PubMed

    Yeo, Belinda; Dowsett, Mitch

    2015-11-01

    Neoadjuvant endocrine treatment has become of increasing interest for downstaging primary ER+ breast cancers as it has become clear that the pathologic complete response rate of luminal tumours to chemotherapy is much lower than that of non-luminal and differs little from that to endocrine therapy. There is much more experience in postmenopausal than premenopausal women. Aromatase inhibitors are generally the agent of choice. Responses are lower in those with the low levels of ER. While duration of endocrine treatment in clinical trials has usually been standardized at around three to four months it is clear that volume reductions continue to occur beyond that time in a large proportion of cases and routine clinical practice is often to treat to maximum response. This relatively slow emergence of downstaging relates to the absence of any increase in apoptosis with endocrine therapy and dependence of responses on the antiproliferative effects of oestrogen withdrawal: apoptosis occurs but at a slightly lower rate such that cell loss is attritional. The dependence of responses on the reduced proliferation underpins the value of Ki67 as an intermediate end-point for treatment benefit with multiple studies having found that relative effects on proliferation by different drugs in neoadjuvant trials match their relative impact on recurrence. While change in Ki67 is now accepted as a validated endpoint for comparing endocrine agents in the neoadjuvant scenario, on-treatment levels of Ki67 are related to long-term prognosis more closely than pretreatment Ki67. The Preoperative Endocrine Prognostic Index (PEPI) that combines residual Ki67 score with measures of on-treatment ER and other clinicopathologic factors has also found application in clinical trials. The potential to make longitudinal assessments of both clinical and biomarker responses has encouraged the development of novel clinical trial designs for assessing the impact of agents that aim to enhance response

  4. Evaluation of 309 environmental chemicals using a mouse embryonic stem cell adherent cell differentiation and cytotoxicity assay.

    PubMed

    Chandler, Kelly J; Barrier, Marianne; Jeffay, Susan; Nichols, Harriette P; Kleinstreuer, Nicole C; Singh, Amar V; Reif, David M; Sipes, Nisha S; Judson, Richard S; Dix, David J; Kavlock, Robert; Hunter, Edward S; Knudsen, Thomas B

    2011-01-01

    The vast landscape of environmental chemicals has motivated the need for alternative methods to traditional whole-animal bioassays in toxicity testing. Embryonic stem (ES) cells provide an in vitro model of embryonic development and an alternative method for assessing developmental toxicity. Here, we evaluated 309 environmental chemicals, mostly food-use pesticides, from the ToxCast™ chemical library using a mouse ES cell platform. ES cells were cultured in the absence of pluripotency factors to promote spontaneous differentiation and in the presence of DMSO-solubilized chemicals at different concentrations to test the effects of exposure on differentiation and cytotoxicity. Cardiomyocyte differentiation (α,β myosin heavy chain; MYH6/MYH7) and cytotoxicity (DRAQ5™/Sapphire700™) were measured by In-Cell Western™ analysis. Half-maximal activity concentration (AC₅₀) values for differentiation and cytotoxicity endpoints were determined, with 18% of the chemical library showing significant activity on either endpoint. Mining these effects against the ToxCast Phase I assays (∼500) revealed significant associations for a subset of chemicals (26) that perturbed transcription-based activities and impaired ES cell differentiation. Increased transcriptional activity of several critical developmental genes including BMPR2, PAX6 and OCT1 were strongly associated with decreased ES cell differentiation. Multiple genes involved in reactive oxygen species signaling pathways (NRF2, ABCG2, GSTA2, HIF1A) were strongly associated with decreased ES cell differentiation as well. A multivariate model built from these data revealed alterations in ABCG2 transporter was a strong predictor of impaired ES cell differentiation. Taken together, these results provide an initial characterization of metabolic and regulatory pathways by which some environmental chemicals may act to disrupt ES cell growth and differentiation. PMID:21666745

  5. Evaluation of 309 Environmental Chemicals Using a Mouse Embryonic Stem Cell Adherent Cell Differentiation and Cytotoxicity Assay

    PubMed Central

    Chandler, Kelly J.; Barrier, Marianne; Jeffay, Susan; Nichols, Harriette P.; Kleinstreuer, Nicole C.; Singh, Amar V.; Reif, David M.; Sipes, Nisha S.; Judson, Richard S.; Dix, David J.; Kavlock, Robert; Hunter, Edward S.; Knudsen, Thomas B.

    2011-01-01

    The vast landscape of environmental chemicals has motivated the need for alternative methods to traditional whole-animal bioassays in toxicity testing. Embryonic stem (ES) cells provide an in vitro model of embryonic development and an alternative method for assessing developmental toxicity. Here, we evaluated 309 environmental chemicals, mostly food-use pesticides, from the ToxCast™ chemical library using a mouse ES cell platform. ES cells were cultured in the absence of pluripotency factors to promote spontaneous differentiation and in the presence of DMSO-solubilized chemicals at different concentrations to test the effects of exposure on differentiation and cytotoxicity. Cardiomyocyte differentiation (α,β myosin heavy chain; MYH6/MYH7) and cytotoxicity (DRAQ5™/Sapphire700™) were measured by In-Cell Western™ analysis. Half-maximal activity concentration (AC50) values for differentiation and cytotoxicity endpoints were determined, with 18% of the chemical library showing significant activity on either endpoint. Mining these effects against the ToxCast Phase I assays (∼500) revealed significant associations for a subset of chemicals (26) that perturbed transcription-based activities and impaired ES cell differentiation. Increased transcriptional activity of several critical developmental genes including BMPR2, PAX6 and OCT1 were strongly associated with decreased ES cell differentiation. Multiple genes involved in reactive oxygen species signaling pathways (NRF2, ABCG2, GSTA2, HIF1A) were strongly associated with decreased ES cell differentiation as well. A multivariate model built from these data revealed alterations in ABCG2 transporter was a strong predictor of impaired ES cell differentiation. Taken together, these results provide an initial characterization of metabolic and regulatory pathways by which some environmental chemicals may act to disrupt ES cell growth and differentiation. PMID:21666745

  6. Ecosystem services as assessment endpoints for ecological risk assessment.

    PubMed

    Munns, Wayne R; Rea, Anne W; Suter, Glenn W; Martin, Lawrence; Blake-Hedges, Lynne; Crk, Tanja; Davis, Christine; Ferreira, Gina; Jordan, Steve; Mahoney, Michele; Barron, Mace G

    2016-07-01

    Ecosystem services are defined as the outputs of ecological processes that contribute to human welfare or have the potential to do so in the future. Those outputs include food and drinking water, clean air and water, and pollinated crops. The need to protect the services provided by natural systems has been recognized previously, but ecosystem services have not been formally incorporated into ecological risk assessment practice in a general way in the United States. Endpoints used conventionally in ecological risk assessment, derived directly from the state of the ecosystem (e.g., biophysical structure and processes), and endpoints based on ecosystem services serve different purposes. Conventional endpoints are ecologically important and susceptible entities and attributes that are protected under US laws and regulations. Ecosystem service endpoints are a conceptual and analytical step beyond conventional endpoints and are intended to complement conventional endpoints by linking and extending endpoints to goods and services with more obvious benefit to humans. Conventional endpoints can be related to ecosystem services even when the latter are not considered explicitly during problem formulation. To advance the use of ecosystem service endpoints in ecological risk assessment, the US Environmental Protection Agency's Risk Assessment Forum has added generic endpoints based on ecosystem services (ES-GEAE) to the original 2003 set of generic ecological assessment endpoints (GEAEs). Like conventional GEAEs, ES-GEAEs are defined by an entity and an attribute. Also like conventional GEAEs, ES-GEAEs are broadly described and will need to be made specific when applied to individual assessments. Adoption of ecosystem services as a type of assessment endpoint is intended to improve the value of risk assessment to environmental decision making, linking ecological risk to human well-being, and providing an improved means of communicating those risks. Integr Environ Assess Manag

  7. Evaluation of Gene Expression Endpoints in the Context of a Xenopus laevis Metamorphosis-based Bioassay to Detect Thyroid Hormone Disruptors

    EPA Science Inventory

    This study accentuates the need to examine multiple tissues and provides critical information required for optimization of exposure regimens and endpoint assessments that focus on the detection of disruption in TH-regulatory systems.

  8. Predicting the endpoints of earthquake ruptures.

    PubMed

    Wesnousky, Steven G

    2006-11-16

    The active fault traces on which earthquakes occur are generally not continuous, and are commonly composed of segments that are separated by discontinuities that appear as steps in map-view. Stress concentrations resulting from slip at such discontinuities may slow or stop rupture propagation and hence play a controlling role in limiting the length of earthquake rupture. Here I examine the mapped surface rupture traces of 22 historical strike-slip earthquakes with rupture lengths ranging between 10 and 420 km. I show that about two-thirds of the endpoints of strike-slip earthquake ruptures are associated with fault steps or the termini of active fault traces, and that there exists a limiting dimension of fault step (3-4 km) above which earthquake ruptures do not propagate and below which rupture propagation ceases only about 40 per cent of the time. The results are of practical importance to seismic hazard analysis where effort is spent attempting to place limits on the probable length of future earthquakes on mapped active faults. Physical insight to the dynamics of the earthquake rupture process is further gained with the observation that the limiting dimension appears to be largely independent of the earthquake rupture length. It follows that the magnitude of stress changes and the volume affected by those stress changes at the driving edge of laterally propagating ruptures are largely similar and invariable during the rupture process regardless of the distance an event has propagated or will propagate. PMID:17108963

  9. Endpoint distinctiveness facilitates analogical mapping in pigeons.

    PubMed

    Hagmann, Carl Erick; Cook, Robert G

    2015-03-01

    Analogical thinking necessitates mapping shared relations across two separate domains. We investigated whether pigeons could learn faster with ordinal mapping of relations across two physical dimensions (circle size & choice spatial position) relative to random mapping of these relations. Pigeons were trained to relate six circular samples of different sizes to horizontally positioned choice locations in a six alternative matching-to-sample task. Three pigeons were trained in a mapped condition in which circle size mapped directly onto choice spatial position. Three other pigeons were trained in a random condition in which the relations between size and choice position were arbitrarily assigned. The mapped group showed an advantage over the random group in acquiring this task. In a subsequent second phase, relations between the dimensions were ordinally reversed for the mapped group and re-randomized for the random group. There was no difference in how quickly matching accuracy re-emerged in the two groups, although the mapped group eventually performed more accurately. Analyses suggested this mapped advantage was likely due to endpoint distinctiveness and the benefits of proximity errors during choice responding rather than a conceptual or relational advantage attributable to the common or ordinal mapping of the two dimensions. This potential difficulty in mapping relations across dimensions may limit the pigeons' capacity for more advanced types of analogical reasoning. This article is part of a Special Issue entitled: Tribute to Tom Zentall. PMID:25447511

  10. Endpoint Distinctiveness Facilitates Analogical Mapping in Pigeons

    PubMed Central

    Hagmann, Carl Erick; Cook, Robert G.

    2015-01-01

    Analogical thinking necessitates mapping shared relations across two separate domains. We investigated whether pigeons could learn faster with ordinal mapping of relations across two physical dimensions (circle size & choice spatial position) relative to random mapping of these relations. Pigeons were trained to relate six circular samples of different sizes to horizontally positioned choice locations in a six alternative matching-to-sample task. Three pigeons were trained in a mapped condition in which circle size mapped directly onto choice spatial position. Three other pigeons were trained in a random condition in which the relations between size and choice position were arbitrarily assigned. The mapped group showed an advantage over the random group in acquiring this task. In a subsequent second phase, reassignment, relations between the dimensions were ordinally reversed for the mapped group and re-randomized for the random group. There was no difference in how quickly matching accuracy re-emerged in the two groups, although the mapped group eventually performed more accurately. Analyses suggested this mapped advantage was likely due endpoint distinctiveness and the benefits of proximity errors during choice responding rather than a conceptual or relational advantage attributable to the common or ordinal map of the two dimensions. This potential difficulty in mapping relations across dimensions may limit the pigeons’ capacity for more advanced types of analogical reasoning. PMID:25447511

  11. Holographic endpoint of spatially modulated phase transition

    SciTech Connect

    Ooguri, Hirosi; Park, Chang-Soon

    2010-12-15

    In a previous paper [S. Nakamura, H. Ooguri, and C. S. Park, Phys. Rev. D 81, 044018 (2010)], we showed that the Reissner-Nordstroem black hole in the five-dimensional anti-de Sitter space coupled to the Maxwell theory with the Chern-Simons term is unstable when the Chern-Simons coupling is sufficiently large. In the dual conformal field theory, the instability suggests a spatially modulated phase transition. In this paper, we construct and analyze nonlinear solutions which describe the endpoint of this phase transition. In the limit where the Chern-Simons coupling is large, we find that the phase transition is of the second order with the mean field critical exponent. However, the dispersion relation with the Van Hove singularity enhances quantum corrections in the bulk, and we argue that this changes the order of the phase transition from the second to the first. We compute linear response functions in the nonlinear solution and find an infinite off-diagonal DC conductivity in the new phase.

  12. Translating Cancer Trial Endpoints Into the Language of Managed Care

    PubMed Central

    KOGAN, ALLAN JAY; HAREN, MELINDA

    2008-01-01

    Oncology endpoints are an essential component of cancer trials, but often they are confusing, making it difficult to evaluate cancer therapies based on trial data. As more oncology agents hit the market and as indications expand for existing products, familiarity with these endpoints is critical for payers when making coverage decisions. PMID:22478698

  13. Current state of clinical end-points assessment in transplant: Key points.

    PubMed

    Hernández, Domingo; Muriel, Alfonso; Abraira, Víctor

    2016-04-01

    Solid organ transplantation is the treatment of choice for patients with end-stage organ disease. However, organ transplantation can stress the cardiovascular system and decrease immune surveillance, leading to early mortality and graft loss due to multiple underlying comorbidities. Clinical end-points in transplant include death and graft failure. Thus, generating accurate predictive models through regression models is crucial to test for definitive clinical post-transplantation end-points. Survival predictive models should assemble efficient surrogate markers or prognostic factors to generate a minimal set of variables derived from a proper modeling strategy through regression models. However, a few critical points should be considered when reporting survival analyses and regression models to achieve proper discrimination and calibration of the predictive models. Additionally, population-based risk scores may underestimate risk prediction in transplant. The application of predictive models in these patients should therefore incorporate both classical and non-classical risk factors, as well as community-based health indicators and transplant-specific factors to quantify the outcomes in terms of survival properly. This review focuses on assessment of clinical end-points in transplant through regression models by combining predictive and surrogate variables, and considering key points in these analyses to accurately predict definitive end-points, which could aid clinicians in decision making. PMID:26948088

  14. Physiologic endpoints for clinical studies for cystic fibrosis.

    PubMed

    Stanojevic, Sanja; Ratjen, Felix

    2016-07-01

    The cystic fibrosis (CF) drug development pipeline promises many exciting new treatments for patients with CF, all which will require clinical studies to prove their benefits on CF lung disease. Historically many pivotal CF studies have used the Forced Expiratory Volume in 1s (FEV1) as the primary outcome measure, and after demonstrating significant improvements in the treatment group relative to placebo have led to regulatory approval of therapies for routine clinical care. Widespread implementation of these therapies has subsequently led to significant improvements in outcomes for patients with CF. While preserving lung function has obvious benefits to CF patients, as more patients maintain FEV1 in the normal range, it has become increasingly difficult to conduct clinical trials using FEV1 as the primary outcome measure. With multiple concurrent trials competing to enroll from the same pool of patients, there is a need for novel approaches to study end points as well as new physiological outcomes for CF therapeutic trials. In this review we will discuss some of the limitations of FEV1 in the current era of CF care, describe alternative physiological endpoints and outline areas for further research. PMID:27316663

  15. Gravity and embryonic development

    NASA Technical Reports Server (NTRS)

    Young, R. S.

    1976-01-01

    The relationship between the developing embryo (both plant and animal) and a gravitational field has long been contemplated. The difficulty in designing critical experiments on the surface of the earth because of its background of 1 g, has been an obstacle to a resolution of the problem. Biological responses to gravity (particularly in plants) are obvious in many cases; however, the influence of gravity as an environmental input to the developing embryo is not as obvious and has proven to be extremely difficult to define. In spite of this, over the years numerous attempts have been made using a variety of embryonic materials to come to grips with the role of gravity in development. Three research tools are available: the centrifuge, the clinostat, and the orbiting spacecraft. Experimental results are now available from all three sources. Some tenuous conclusions are drawn, and an attempt at a unifying theory of gravitational influence on embryonic development is made.

  16. Exactly solvable model for the QCD tricritical endpoint

    SciTech Connect

    Bugaev, K. A.

    2008-09-15

    An inclusion of temperature and chemical-potential-dependent surface-tension in the gas of quark-gluon bags model resolves a long-standing problem of a unified description of the first-and second-order phase transition with the crossover. The suggested model has an exact analytical solution and allows one to rigorously study the vicinity of the critical endpoint of the deconfinement phase transition. It is found that, at the curve of a zero surface-tension coefficient, there must exist the surface-induced phase transition of the seond or higher order. The present model predicts that the critical endpoint of quantum chromodynamics is the tricritical endpoint.

  17. Composite risk scores and composite endpoints in the risk prediction of outcomes in anticoagulated patients with atrial fibrillation. The Loire Valley Atrial Fibrillation Project.

    PubMed

    Banerjee, A; Fauchier, L; Bernard-Brunet, A; Clementy, N; Lip, G Y H

    2014-03-01

    Several validated risk stratification schemes for prediction of ischaemic stroke (IS)/thromboembolism (TE) and major bleeding are available for patients with non-valvular atrial fibrillation (NVAF). On the basis for multiple common risk factors for IS/TE and bleeding, it has been suggested that composite risk prediction scores may be more practical and user-friendly than separate scores for bleeding and IS/TE. In a long-term prospective hospital registry of anticoagulated patients with newly diagnosed AF, we compared the predictive value of existing risk prediction scores as well as composite risk scores, and also compared these risk scoring systems using composite endpoints. Endpoint 1 was the simple composite of IS and major bleeds. Endpoint 2 was based on a composite of IS plus intracerebral haemorrhage (ICH). Endpoint 3 was based on weighted coefficients for IS/TE and ICH. Endpoint 4 was a composite of stroke, cardiovascular death, TE and major bleeding. The incremental predictive value of these scores over CHADS2 (as reference) for composite endpoints was assessed using c-statistic, net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Of 8,962 eligible individuals, 3,607 (40.2%) had NVAF and were on OAC at baseline. There were no statistically significant differences between the c-statistics of the various risk scores, compared with the CHADS2 score, regardless of the endpoint. For the various risk scores and various endpoints, NRI and IDI did not show significant improvement (≥1%), compared with the CHADS2 score. In conclusion, composite risk scores did not significantly improve risk prediction of endpoints in patients with NVAF, regardless of how endpoints were defined. This would support individualised prediction of IS/TE and bleeding separately using different separate risk prediction tools, and not the use of composite scores or endpoints for everyday 'real world' clinical practice, to guide decisions on

  18. 21 CFR 601.41 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or irreversible morbidity. 601.41 Section 601.41 Food... Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

  19. 21 CFR 601.41 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or irreversible morbidity. 601.41 Section 601.41 Food... Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

  20. 21 CFR 601.41 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or irreversible morbidity. 601.41 Section 601.41 Food... Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

  1. 21 CFR 601.41 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or irreversible morbidity. 601.41 Section 601.41 Food... Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

  2. Endpoint behavior of high-energy scattering cross sections

    SciTech Connect

    Chay, Junegone; Kim, Chul

    2010-11-01

    In high-energy processes near the endpoint, there emerge new contributions associated with spectator interactions. Away from the endpoint region, these new contributions are suppressed compared to the leading contribution, but the leading contribution becomes suppressed as we approach the endpoint and the new contributions become comparable. We present how the new contributions scale as we reach the endpoint and show that they are comparable to the suppressed leading contributions in deep inelastic scattering by employing a power-counting analysis. The hadronic tensor in deep inelastic scattering is shown to factorize including the spectator interactions, and it can be expressed in terms of the light cone distribution amplitudes of initial hadrons. We also consider the contribution of the spectator contributions in Drell-Yan processes. Here the spectator interactions are suppressed compared to double parton annihilation according to the power counting.

  3. Determination of 50% endpoint titer using a simple formula.

    PubMed

    Ramakrishnan, Muthannan Andavar

    2016-05-12

    Two commonly used methods for calculating 50% endpoint using serial dilutions are Spearman-Karber method and Reed and Muench method. To understand/apply the above formulas, moderate statistical/mathematical skills are necessary. In this paper, a simple formula/method for calculating 50% endpoints has been proposed. The formula yields essentially similar results as those of the Spearman-Karber method. The formula has been rigorously evaluated with several samples. PMID:27175354

  4. Determination of 50% endpoint titer using a simple formula

    PubMed Central

    Ramakrishnan, Muthannan Andavar

    2016-01-01

    Two commonly used methods for calculating 50% endpoint using serial dilutions are Spearman-Karber method and Reed and Muench method. To understand/apply the above formulas, moderate statistical/mathematical skills are necessary. In this paper, a simple formula/method for calculating 50% endpoints has been proposed. The formula yields essentially similar results as those of the Spearman-Karber method. The formula has been rigorously evaluated with several samples. PMID:27175354

  5. Motor contagion: the contribution of trajectory and end-points.

    PubMed

    Roberts, James W; Hayes, Spencer J; Uji, Makoto; Bennett, Simon J

    2015-07-01

    Increased involuntary arm movement deviation when observing an incongruent human arm movement has been interpreted as a strong indicator of motor contagion. Here, we examined the contribution of trajectory and end-point information on motor contagion by altering congruence between the stimulus and arm movement. Participants performed cyclical horizontal arm movements whilst simultaneously observing a stimulus representing human arm movement. The stimuli comprised congruent horizontal movements or vertical movements featuring incongruent trajectory and end-points. A novel, third, stimulus comprised curvilinear movements featuring congruent end-points, but an incongruent trajectory. In Experiment 1, our dependent variables indicated increased motor contagion when observing the vertical compared to horizontal movement stimulus. There was even greater motor contagion in the curvilinear stimulus condition indicating an additive effect of an incongruent trajectory comprising congruent end-points. In Experiment 2, this additive effect was also present when facing perpendicular to the display, and thus with end-points represented as a product of the movement rather than an external spatial reference. Together, these findings support the theory of event coding (Hommel et al., Behav Brain Sci 24:849-878, 2001), and the prediction that increased motor contagion takes place when observed and executed actions share common features (i.e., movement end-points). PMID:24947759

  6. Programming embryonic stem cells to neuronal subtypes

    PubMed Central

    Peljto, Mirza; Wichterle, Hynek

    2010-01-01

    Richness of neural circuits and specificity of neuronal connectivity depends on the diversification of nerve cells into functionally and molecularly distinct subtypes. While efficient methods for directed differentiation of embryonic stem cells (ESCs) into multiple principal neuronal classes have been established, only a few studies systematically examined the subtype diversity of in vitro derived nerve cells. Here we review evidence based on molecular and in vivo transplantation studies that ESC-derived spinal motor neurons and cortical layer V pyramidal neurons acquire subtype specific functional properties. We discuss similarities and differences in the role of cell intrinsic transcriptional programs, extrinsic signals and cell-cell interactions during subtype diversification of the two classes of nerve cells. We conclude that the high degree of fidelity with which differentiating ESCs recapitulate normal embryonic development provides a unique opportunity to explore developmental processes underlying specification of mammalian neuronal diversity in a simplified and experimentally accessible system. PMID:20970319

  7. 77 FR 46444 - Gastroenterology Regulatory Endpoints and the Advancement of Therapeutics (GREAT); Public Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-03

    ... HUMAN SERVICES Food and Drug Administration Gastroenterology Regulatory Endpoints and the Advancement of... announcing a 4-day public workshop entitled ``Gastroenterology Regulatory Endpoints and the Advancement of... endpoints that can support drug development in the following disease areas: Eosinophilic...

  8. Preliminary remediation goals for ecological endpoints

    SciTech Connect

    Efroymson, R.A.; Suter, G.W. II; Sample, B.E.; Jones, D.S.

    1996-07-01

    Preliminary remediation goals (PRGs) are useful for risk assessment and decision making at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites. PRGs are upper concentration limits for specific chemicals in specific environmental media that are anticipated to protect human health or the environment. They can be used for multiple remedial investigations at multiple facilities. In addition to media and chemicals of potential concern, the development of PRGs generally requires some knowledge or anticipation of future land use. In Preliminary Remediation Goals for Use at the U.S. Department of Energy Oak Ridge Operations Office (Energy Systems 1995), PRGs intended to protect human health were developed with guidance from Risk Assessment Guidance for Superfund: Volume I - Human Health Evaluation Manual, Part B (RAGS) (EPA 1991). However, no guidance was given for PRGs based on ecological risk. The numbers that appear in this volume have, for the most part, been extracted from toxicological benchmarks documents for Oak Ridge National Laboratory (ORNL) and have previously been developed by ORNL. The sources of the quantities, and many of the uncertainties associated with their derivation, are described in this technical memorandum.

  9. Magnesium and Embryonic Development

    PubMed Central

    Komiya, Yuko; Su, Li-Ting; Chen, Hsiang-Chin; Habas, Raymond; Runnels, Loren W.

    2014-01-01

    Important for energy metabolism, neurotransmission, bone stability, and other cellular functions, Mg2+ has well-established and undisputedly critical roles in adult tissues. Its contributions to early embryonic development are less clearly understood. For decades it has been known that gestational Mg2+ deficiency in rodents produces teratogenic effects. More recent studies have linked deficiency in this vital cation to birth defects in humans, including spina bifida, a neural fold closure defect in humans that occurs at an average rate of 1 per 1000 pregnancies. The first suggestion that Mg2+ may be playing a more specific role in early development arose from studies of the TRPM7 and TRPM6 ion channels. TRPM7 and TRPM6 are divalent-selective ion channels in possession of their own kinase domains that have been implicated in the control of Mg2+ homeostasis in vertebrates. Disruption of the functions of these ion channels in mice as well as in frogs interferes with gastrulation, a pivotal process during early embryonic development that executes the emergence of the body plan and closure of the neural tube. Surprisingly, gastrulation defects produced by depletion of TRPM7 can be prevented by Mg2+ supplementation, indicating an essential role for Mg2+ in gastrulation and neural fold closure. The aim of this review is to summarize the data emerging from molecular genetic, biochemical and electrophysiological studies of TRPM6 and TRPM7 and provide a model of how Mg2+, through these unique channel-kinases, may be impacting early embryonic development. PMID:24721994

  10. Intermediate markers as surrogate endpoints in cancer research.

    PubMed

    Schatzkin, A

    2000-08-01

    Because studies with surrogate cancer endpoints can be smaller, faster, and substantially less expensive than those with frank cancer outcomes, the use of surrogate endpoints is undeniably attractive. This attractiveness is likely to grow in coming years as the rapidly advancing discoveries in cell and molecular biology generate new therapies requiring testing and new markers that could plausibly serve as surrogates for cancer. Surrogate endpoint studies can certainly be suggestive. They continue to play a legitimate role in phase II studies, and they may give the right answers about intervention effects on or exposure associations with cancer. The problem is the uncertainty attached to most potential surrogates. Except for those few surrogates that are both necessary for and developmentally relatively close to cancer, the existence of plausible alternative pathways makes inferences about cancer from many surrogates problematic. Merely being on the causal pathway to cancer does not in itself constitute surrogate validity. It is the totality of causal connections that is critical. There is, unfortunately, a fairly extensive history of quite plausible surrogate markers giving the wrong answer about various chronic disease therapies. There is no reason to believe that cancer surrogacy is immune to such inferential difficulties. This article is, in part, an invitation, even a plea, for researchers to carry out the investigations necessary to evaluate potential surrogates, particularly surrogate-cancer studies and intervention or exposure-surrogate-cancer mediation analyses. Such studies are needed to generalize from surrogate endpoint findings to cancer. There is, however, an implicit and perhaps unavoidable irony here: the large, long, expensive studies required to evaluate potential surrogates fully are precisely the studies that surrogates were designed to replace. The exposure dependence alluded to earlier complicates matters further: establishing validity for a

  11. Endpoints for Comparative Effectiveness Research in Heart Failure

    PubMed Central

    Allen, Larry A.; Spertus, John A.

    2012-01-01

    With the increasing availability of therapeutic strategies (drugs, devices, disease management systems) and the growing complexity of health care delivery, there is an attendant need for objective evidence of the tangible benefits of different approaches to care. This is particularly true for patients with heart failure, a common, morbid, and resource-intensive disease. There are few well-proven therapies for patients with acute decompensation or for patients with normal LVEF. Comparative effectiveness research (CER) offers an important avenue for making progress in the field. However, CER, like any well-designed research program, requires the explicit articulation of clinically important outcomes to be compared. For patients with heart failure, there is a need to develop endpoint measures that capture the totality of potential benefits and risks for alternative therapeutic approaches. Ultimately, for one therapeutic approach to be considered superior to another, it must improve one of three relevant endpoints: make patients live longer, make them feel better, or save money without adversely affecting the other two goals. Importantly, these outcomes must be measured directly and surrogates should be avoided, even if such surrogates appear to be associated with clinically meaningful, patient-centered outcomes. In this review, we discuss the available CER endpoint domains from both a clinical and a statistical perspective, summarize the wide variety of endpoints used in CER studies, and suggest steps for greater standardization of endpoints across CER studies of patients with heart failure. PMID:23168314

  12. Semiparametric inference for surrogate endpoints with bivariate censored data.

    PubMed

    Ghosh, Debashis

    2008-03-01

    Considerable attention has been recently paid to the use of surrogate endpoints in clinical research. We deal with the situation where the two endpoints are both right censored. While proportional hazards analyses are typically used for this setting, their use leads to several complications. In this article, we propose the use of the accelerated failure time model for analysis of surrogate endpoints. Based on the model, we then describe estimation and inference procedures for several measures of surrogacy. A complication is that potentially both the independent and dependent variable are subject to censoring. We adapt the Theil-Sen estimator to this problem, develop the associated asymptotic results, and propose a novel resampling-based technique for calculating the variances of the proposed estimators. The finite-sample properties of the estimation methodology are assessed using simulation studies, and the proposed procedures are applied to data from an acute myelogenous leukemia clinical trial. PMID:17651457

  13. Continuous Speech Recognition without End-point Detection

    NASA Astrophysics Data System (ADS)

    Segawa, Osamu; Takeda, Kazuya; Itakura, Fumitada

    A new continuous speech recognition method that does not need the explicit speech end-point detection is proposed. A one-pass decoding algorithm is modified to decode the input speech of infinite length so that, with appropriate non-speech models for silence and ambient noises, continuous speech recognition can be executed without the explicit end-point detection. The basic algorithm 1) decodes a processing block of the predetermined length, 2) tracebacks and finds the boundaries of the processing blocks where the word history in the preceding processing block is merged into one, and 3) restarts decoding from the boundary frame with the merged word history. The effectiveness of the method is verified by the spoken dialogue transcription experiments. With a 5-minute dialogue in a moving car, the proposed method gives better results in word accuracy than the results using the explicit end-point detection method and the conventional one-pass decoder.

  14. Origin of electrical signals for plasma etching endpoint detection

    SciTech Connect

    Sobolewski, Mark A.

    2011-11-14

    Electrical signals are used for endpoint detection in plasma etching, but the origin of the electrical changes observed at endpoint is not known. They may be caused by changes in the gas-phase densities of etch products and reactants or by changes in substrate surface properties such as photoemitted or ion-induced electron yield. To investigate these effects, experiments were performed in an inductively coupled, rf-biased reactor, during CF{sub 4}/Ar etches of SiO{sub 2} films on Si wafers. The rf bias impedance was measured vs. time during etching, simultaneous with Langmuir probe measurements. At endpoint, a decrease in impedance coincided with increases in ion current and electron energy. The data, analyzed by a numerical model of the discharge, indicate that changes in electron emission yield were relatively insignificant or entirely absent. Thus the impedance change is not a surface effect but is, instead, predominantly or entirely a gas-phase phenomenon.

  15. The Roberge-Weiss phase transition and its endpoint

    NASA Astrophysics Data System (ADS)

    Kouno, Hiroaki; Sakai, Yuji; Kashiwa, Kouji; Yahiro, Masanobu

    2009-11-01

    The Roberge-Weiss (RW) phase transition in the imaginary chemical potential region is analyzed by the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model. In the RW phase transition, the charge-conjugation symmetry is spontaneously broken, while the extended {\\mathbb Z}_{3} symmetry (the RW periodicity) is preserved. The RW transition is of second order at the endpoint. At the zero chemical potential, a crossover deconfinement transition appears as a remnant of the second-order RW phase transition at the endpoint, while the charge-conjugation symmetry is always preserved.

  16. Dependence of QSAR models on the selection of trial descriptor sets: a demonstration using nanotoxicity endpoints of decorated nanotubes.

    PubMed

    Shao, Chi-Yu; Chen, Sing-Zuo; Su, Bo-Han; Tseng, Yufeng J; Esposito, Emilio Xavier; Hopfinger, Anton J

    2013-01-28

    Little attention has been given to the selection of trial descriptor sets when designing a QSAR analysis even though a great number of descriptor classes, and often a greater number of descriptors within a given class, are now available. This paper reports an effort to explore interrelationships between QSAR models and descriptor sets. Zhou and co-workers (Zhou et al., Nano Lett. 2008, 8 (3), 859-865) designed, synthesized, and tested a combinatorial library of 80 surface modified, that is decorated, multi-walled carbon nanotubes for their composite nanotoxicity using six endpoints all based on a common 0 to 100 activity scale. Each of the six endpoints for the 29 most nanotoxic decorated nanotubes were incorporated as the training set for this study. The study reported here includes trial descriptor sets for all possible combinations of MOE, VolSurf, and 4D-fingerprints (FP) descriptor classes, as well as including and excluding explicit spatial contributions from the nanotube. Optimized QSAR models were constructed from these multiple trial descriptor sets. It was found that (a) both the form and quality of the best QSAR models for each of the endpoints are distinct and (b) some endpoints are quite dependent upon 4D-FP descriptors of the entire nanotube-decorator complex. However, other endpoints yielded equally good models only using decorator descriptors with and without the decorator-only 4D-FP descriptors. Lastly, and most importantly, the quality, significance, and interpretation of a QSAR model were found to be critically dependent on the trial descriptor sets used within a given QSAR endpoint study. PMID:23252880

  17. 21 CFR 601.41 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... effect on a clinical endpoint other than survival or irreversible morbidity. 601.41 Section 601.41 Food... Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or... well-controlled clinical trials establishing that the biological product has an effect on a...

  18. 21 CFR 314.510 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or irreversible morbidity. 314.510 Section 314.510 Food... Serious or Life-Threatening Illnesses § 314.510 Approval based on a surrogate endpoint or on an effect...

  19. 21 CFR 314.510 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or irreversible morbidity. 314.510 Section 314.510 Food... Serious or Life-Threatening Illnesses § 314.510 Approval based on a surrogate endpoint or on an effect...

  20. 21 CFR 314.510 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or irreversible morbidity. 314.510 Section 314.510 Food... Serious or Life-Threatening Illnesses § 314.510 Approval based on a surrogate endpoint or on an effect...

  1. 21 CFR 314.510 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival or irreversible morbidity. 314.510 Section 314.510 Food... Serious or Life-Threatening Illnesses § 314.510 Approval based on a surrogate endpoint or on an effect...

  2. ECOLOGICAL ENDPOINT MODELING: EFFECTS OF SEDIMENT ON FISH POPULATIONS

    EPA Science Inventory

    Sediment is one of the main stressors of concern for TMDLs (Total Maximum Daily Loads) for streams, and often it is a concern because of its impact on biological endpoints. The National Research Council (NRC) has recommended that the EPA promote the development of models that ca...

  3. Comparison and Evaluation of Laboratory and Field Measured Bioaccumulation Endpoints

    EPA Science Inventory

    Evaluation of bioaccumulation endpoints on a fugacity basis allows provides a framework to assess the biomagnification potential of a chemical and assess data deficiencies, i.e., uncertainties and lack of data. In addition, it is suggested that additional guidance is needed in o...

  4. Expanding the ecotoxicological toolbox: the inclusion of polychaete reproductive endpoints.

    PubMed

    Lewis, Ceri; Watson, Gordon J

    2012-04-01

    In the last 15 years the diversity of pollutants and routes of impact have increased. However, the polychaete families, species and endpoints investigated have remained fairly constant. Reproductive outputs are more ecologically relevant than adult physiological or biochemical changes. Nevertheless, there remains a paucity of data on the reproductive responses of the popular species to pollutants which limits our ability to understand the true ecological impacts of such contaminants on natural populations. We highlight the current knowledge gaps in our understanding of the impacts of pollutants on the 'model' species' reproductive biology and therefore the potential ecological impacts of such contaminants on their natural populations, and the potential benefits of a wider use of polychaete reproductive endpoints for ecotoxicological assessments. The following priority areas are suggested for inclusion in the polychaete ecotoxicology toolbox: 1. Include reproductive endpoints as assessments of ecotoxicology for the traditional 'model' species and those that have different reproductive traits to ensure broad ecological relevance. 2. Nereids and Arenicola marina should be used to investigate the interaction of pollutants with the endocrine/environmental control of reproduction. 3. Polychaetes are ideal for addressing the under representation of male eco-toxicity effects. 4. Emerging pollutants should be assessed with reproductive endpoints together with the traditional biomarkers. 5. Effects of pollutants on larval behaviour need to be explored considering the limited but equivocal results so far. PMID:21872922

  5. Defining response in migraine: which endpoints are important?

    PubMed

    Edmeads, John

    2005-01-01

    The primary endpoint traditionally measured in clinical trials of triptans for acute migraine therapy has been 2-hour pain relief, a decrease in pain intensity from moderate/severe to mild/none. Although harder to achieve, endpoints such as 2-hour pain free and the composite measure sustained pain free are now preferred as they better reflect what patients desire from medication, namely rapid onset of action, and complete and lasting relief of pain. A comprehensive meta-analysis has shown that oral triptans differ in their ability to achieve these endpoints, with almotriptan 12.5 mg, eletriptan 80 mg and rizatriptan 10 mg providing the highest likelihood of success. Although all triptans have simple and consistent pharmacokinetic features, they also have specific differences that may play a part in their differing clinical attributes. Incorporating tolerability to generate a more stringent endpoint, sustained pain free with no adverse events (SNAE), may provide an even better representation of patients' expectations. Comparison of SNAE rates using data from the meta-analysis of oral triptans indicates that almotriptan 12.5 mg has the best balance of high efficacy and good tolerability. PMID:15920334

  6. Is Suicide Ideation a Surrogate Endpoint for Geriatric Suicide?

    ERIC Educational Resources Information Center

    Links, Paul S.; Heisel, Marnin J.; Quastel, Adam

    2005-01-01

    The present study explored the validity of treating suicide ideation as a surrogate endpoint that can serve as a proxy for suicide in clinical intervention research with suicidal seniors. Two criteria; that suicide ideation is modulated by the proposed intervention and that modulation of suicide ideation leads to a quantitative reduction in…

  7. Immediate skin responses to laser and light treatments: Therapeutic endpoints: How to obtain efficacy.

    PubMed

    Wanner, Molly; Sakamoto, Fernanda H; Avram, Mathew M; Chan, Henry H; Alam, Murad; Tannous, Zeina; Anderson, R Rox

    2016-05-01

    Clinical endpoints are immediate or early tissue reactions that occur during laser treatment. They can guide the laser surgeon in delivering safe and effective laser treatment. Some endpoints act as warning signs of injury to the skin; others can indicate a therapeutic response. The first article in this series reviewed undesirable and warning endpoints, and this article focuses on desirable and therapeutic endpoints and their underlying mechanisms in laser surgery. We will also review treatments without clinical endpoints. PMID:27085228

  8. Segmentation of endpoint trajectories does not imply segmented control.

    PubMed

    Sternad, D; Schaal, S

    1999-01-01

    While it is generally assumed that complex movements consist of a sequence of simpler units, the quest to define these units of action, or movement primitives, remains an open question. In this context, two hypotheses of movement segmentation of endpoint trajectories in three-dimensional human drawing movements are reexamined: (1) the stroke-based segmentation hypothesis based on the results that the proportionality coefficient of the two-thirds power law changes discontinuously with each new "stroke," and (2) the segmentation hypothesis inferred from the observation of piecewise planar endpoint trajectories of three-dimensional drawing movements. In two experiments human subjects performed a set of elliptical and figure eight patterns of different sizes and orientations using their whole arm in three dimensions. The kinematic characteristics of the endpoint trajectories and the seven joint angles of the arm were analyzed. While the endpoint trajectories produced similar segmentation features to those reported in the literature, analyses of the joint angles show no obvious segmentation but rather continuous oscillatory patterns. By approximating the joint angle data of human subjects with sinusoidal trajectories, and by implementing this model on a 7-degree-of-freedom (DOF) anthropomorphic robot arm, it is shown that such a continuous movement strategy can produce exactly the same features as observed by the above segmentation hypotheses. The origin of this apparent segmentation of endpoint trajectories is traced back to the nonlinear transformations of the forward kinematics of human arms. The presented results demonstrate that principles of discrete movement generation may not be reconciled with those of rhythmic movement as easily as has been previously suggested, while the generalization of nonlinear pattern generators to arm movements can offer an interesting alternative to approach the question of units of action. PMID:9928796

  9. Comparing and Combining Biomarkers as Principle Surrogates for Time-to-Event Clinical Endpoints

    PubMed Central

    Gabriel, Erin E.; Sachs, Michael C.; Gilbert, Peter B.

    2016-01-01

    Principal surrogate endpoints are useful as targets for Phase I and II trials. In many recent trials, multiple post-randomization biomarkers are measured. However, few statistical methods exist for comparison of or combination of biomarkers as principal surrogates and none of these methods to our knowledge utilize time-to-event clinical endpoint information. We propose a Weibull model extension of the semi-parametric estimated maximum likelihood method of Huang and Gilbert [1] that allows for the inclusion of multiple biomarkers in the same risk model as multivariate candidate principal surrogates. We propose several methods for comparing candidate principal surrogates and evaluating multivariate principal surrogates. These include the time-dependent and surrogate-dependent true and false positive fraction, the time-dependent and the integrated standardized total gain and the cumulative distribution function of the risk difference. We illustrate the operating characteristics of our proposed methods in simulations and outline how these statistics can be used to evaluate and compare candidate principal surrogates. We use these methods to investigate candidate surrogates in the Diabetes Control and Complications Trial. PMID:25352131

  10. Genetic evaluation of beef carcass data using different endpoint adjustments.

    PubMed

    Rumph, J M; Shafer, W R; Crews, D H; Enns, R M; Lipsey, R J; Quaas, R L; Pollak, E J

    2007-05-01

    Carcass data from 6,795 Simmental-sired animals born from 1992 to 2001 were used to determine whether adjustment to a constant age, back-fat, HCW, or marbling score would result in differences in heritability of the carcass traits and, correspondingly, if EPD calculated using those variance components and adjustments would result in sire reranking. The endpoints were age (EPA), backfat (EPF), HCW (EPC), or marbling (EPM). The traits analyzed were 12th-rib backfat (FAT), HCW, marbling (MRB), LM area (LMA), and percentage retail cuts (PRC). The data were analyzed using an animal model, where contemporary group was included as a fixed effect and was composed of slaughter date, sex, and herd. Random effects included in the model were direct genetic and residual. Estimates of heritability ranged from 0.12 to 0.14, 0.32 to 0.34, and 0.26 to 0.27 for FAT, HCW, and LMA, respectively, for the corresponding endpoints. Heritability for MRB was estimated to be 0.27 at all endpoints. For PRC, estimates of heritability were more variable, with estimates of 0.23 +/- 0.05, 0.32 +/- 0.05, 0.21 +/- 0.05, and 0.20 +/- 0.04 for EPA, EPF, EPC, and EPM, respectively. However, because the EPF and EPC adjustments adjust for a component trait of PRC (FAT and HCW, respectively), they may be altering the trait to one different from PRC. Spearman rank correlations between EPD within a trait using EPA compared with the other endpoints were >0.90 (P < 0.01) for FAT, HCW, MRB, and LMA. For PRC, Spearman rank correlations with EPA EPD were 0.73 (P < 0.01), 0.93 (P < 0.01), and 0.95 (P < 0.01) for EPF, EPC, and EPM, respectively. For most traits and endpoints, there was little reranking among sires when alternative endpoints were used. However, adjusting PRC to EPF appears to result in a greater heritability and substantial re-ranking of sires, potentially due to the adjustment changing the trait to one other than PRC. PMID:17224467

  11. Changing the endpoints for determining effective obesity management.

    PubMed

    Ross, Robert; Blair, Steve; de Lannoy, Louise; Després, Jean-Pierre; Lavie, Carl J

    2015-01-01

    Health authorities worldwide recommend weight loss as a primary endpoint for effective obesity management. Despite a growing public awareness of the importance of weight loss and the spending of billions of dollars by Americans in attempts to lose weight, obesity prevalence continues to rise. In this report we argue that effective obesity management in today's environment will require a shift in focus from weight loss as the primary endpoint, to improvements in the causal behaviors; diet and exercise/physical activity (PA). We reason that increases in PA combined with a balanced diet are associated with improvement in many of the intermediate risk factors including cardiorespiratory fitness (CRF) associated with obesity despite minimal or no weight loss. Consistent with this notion, we suggest that a focus on healthy behaviors for the prevention of additional weight gain may be an effective way of managing obesity in the short term. PMID:25459976

  12. Roberge-Weiss endpoint in Nf=2 QCD

    NASA Astrophysics Data System (ADS)

    Bonati, Claudio; Cossu, Guido; D'Elia, Massimo; Sanfilippo, Francesco

    2011-03-01

    We present the results of extensive simulations regarding the critical behavior at the endpoint of the Roberge-Weiss transition for Nf=2 QCD. We confirm early evidence, presented in Ref. [M. D’Elia and F. Sanfilippo, Phys. Rev. DPRVDAQ1550-799810.1103/PhysRevD.80.111501 80, 111501(R) (2009).], according to which the Roberge-Weiss endpoint is first order in the limit of large or small quark masses, and second order for intermediate masses. A systematic study of the transition strength as a function of the quark mass in the first order regions, permits us to estimate the tricritical values of the quark mass separating the second order region from the first order ones.

  13. Endpoints for Mouse Abdominal Tumor Models: Refinement of Current Criteria

    PubMed Central

    Paster, Eden V; Villines, Kimberly A; Hickman, Debra L

    2009-01-01

    Accurate, rapid, and noninvasive health assessments are required to establish more appropriate endpoints in mouse cancer models where tumor size is not easily measured. We evaluated potential endpoints in mice with experimentally induced peritoneal lymphoma, an abdominal tumor model, by comparing body weight, body condition, and behavior with those of a control group of mice not developing lymphoma. Our hypothesis was that body weight would increase or plateau, whereas body condition and behavioral scores would decrease, as disease progressed. Results indicated that body weight did not differ significantly between the control and experimental groups, but the experimental group experienced significant decreases in both body condition and behavioral scores. Our results support the use of body condition and behavioral scoring as adjunctive assessment methods for mice involved in abdominal lymphoma tumor studies in which health may decline despite an increase or plateau in body weight. PMID:19619413

  14. Cervical cancer chemoprevention, vaccines, and surrogate endpoint biomarkers.

    PubMed

    Follen, Michele; Meyskens, Frank L; Alvarez, Ronald D; Walker, Joan L; Bell, Maria C; Storthz, Karen Adler; Sastry, Jagannadha; Roy, Krishnendu; Richards-Kortum, Rebecca; Cornelison, Terri L

    2003-11-01

    At the Second International Conference on Cervical Cancer, held April 11-14, 2002, experts in cervical cancer prevention, detection, and treatment reviewed the need for more research in chemoprevention, including prophylactic and therapeutic vaccines, immunomodulators, peptides, and surrogate endpoint biomarkers. Investigators and clinicians noted the need for more rigorous Phase I randomized clinical trials, more attention to the risk factors that can affect study results in this patient population, and validation of optical technologies that will provide valuable quantitative information in real time regarding disease regression and progression. They discussed the role of the human papillomavirus (HPV) in cervical cancer development and the importance of developing strategies to suppress HPV persistence and progression. Results in Phase I randomized clinical trials have been disappointing because few have demonstrated statistically significant regression attributable to the agent tested. Researchers recommended using a transgenic mouse model to test and validate new compounds, initiating vaccine and immunomodulator trials, and developing immunologic surrogate endpoint biomarkers. PMID:14603541

  15. Digit mechanics in relation to endpoint compliance during precision pinch

    PubMed Central

    Nataraj, Raviraj; Audu, Musa L.; Li, Zong-Ming

    2015-01-01

    This study investigates the mechanics of the thumb and index finger in relation to compliant endpoint forces during precision pinch. The objective was to gain insight into how individuals modulate motor output at the digit endpoints and joints according to compliance-related sensory feedback across the digits. Thirteen able-bodied subjects performed precision pinch upon elastic resistance bands of a customized apparatus instrumented with six degree-of-freedom load-cells. Compliance levels were discretely adjusted according to the number of bands connected. Subjects were provided visual feedback to control the rate of force application. Fifteen repetitions of low-to-moderate force (<20 N) pinches were analyzed at each of five compliance levels, during which force and motion data were collected. Joint angles and moments normalized by pinch force magnitude were computed. Second-order polynomials were used to characterize joint mechanics as a function of compliance. The joint degrees-of-freedom (DOFs) at the finger showed greater dependence on compliance for angular position while the thumb joint DOFs demonstrated greater dependence for normalized joint moment. The digits also adjusted coordination of their endpoint forces according to compliance. Overall, the finger may be altering its position to increase load to the joints of the thumb with changing compliance. These findings describe naturally emergent changes in digit mechanics for compliant precision pinch, which involves motor execution in response to endpoint sensory feedback. Identifying and understanding these motor patterns may provide theoretical basis for restoring and rehabilitating sensorimotor pathologies of the hand. PMID:25596633

  16. Second critical endpoints and their bearing on subduction zone magmatism

    NASA Astrophysics Data System (ADS)

    Mibe, K.

    2011-12-01

    Understanding the phase relations in silicate-H2O systems is fundamental for clarifying the physical and chemical evolution of the Earth, because H2O affects melting temperature of rocks, composition of magmas generated, and rheology of rocks. Under high pressure and high temperature conditions, it is known that the solubility of both water in silicate melt and silicate in aqueous fluid increases with increasing pressure. As a result, silicate melt and aqueous fluid in the Earth's interior is expected to become supercritical fluid and the hydrous solidus of the system can no longer be defined beyond a certain critical condition. This condition is called the second critical endpoint and is the point of intersection between the critical curve and hydrous solidus. In recent years, the second critical endpoints in the systems peridotite-H2O and basalt-H2O have been determined using high-pressure and high-temperature X-ray radiography technique [Mibe et al., 2007, JGR; 2011, PNAS]. In these studies, it was concluded that the second critical endpoints in the systems peridotite-H2O and basalt-H2O occurred at around 3.8 and 3.4 GPa, respectively. These results suggest that the aqueous fluid and silicate melt becomes indistinguishable at the depths deeper than ~120 km in the mantle wedge peridotite and ~100 km in the subducting basaltic oceanic crust in subduction zones. The melting temperature of the subducting oceanic crust can no longer be defined beyond this critical condition. The fluid released from subducting oceanic crust at depths deeper than 100 km under volcanic arcs are supercritical fluid rather than aqueous fluid and/or hydrous melts. It is suggested that the position of the second critical endpoint explains why there is a limitation of slab depth (~90 km) where Adakitic magmas are produced and also explains the origin of across-arc geochemical variations of trace elements in volcanic rocks in subduction zones.

  17. Evaluation of embryotoxicity for major components of herbal extracts using the chick embryonic heart micromass and mouse D3 embryonic stem cell systems.

    PubMed

    Mohammed, Omar J; Latif, Muhammad Liaque; Pratten, Margaret K

    2016-01-01

    Herbal remedies are often used during the early stages of pregnancy, being considered 'harmless' and 'natural'. There are insufficient data regarding their potential embryotoxicity. The main components of selected herbs, including 6-gingerol from ginger, Ginkgolide A and Ginkgolide B from gingko biloba and Ginsenoside Rg1 from ginseng, have been investigated using chick embryonic heart micromass and Mouse D3 embryonic stem cells. The potential effects were evaluated via alteration in contractility, cell viability, and cell protein content. The myocytes in both systems were also demonstrated by immunocytochemistry using a specific cardiomyocyte marker (α-actinin). For 6-gingerol, Ginkgolide A, Ginkgolide B and Ginsenoside Rg1 in both methods, at moderate to high concentrations, there were alterations in the values for the endpoints. These data indicate that herbal remedies used in the first trimester of pregnancy might not be safe for fetal development. PMID:26708230

  18. Visual information throughout a reach determines endpoint precision.

    PubMed

    Ma-Wyatt, Anna; McKee, Suzanne P

    2007-05-01

    People make rapid, goal-directed movements to interact with their environment. Because these movements have consequences, it is important to be able to control them with a high level of precision and accuracy. Our hypothesis is that vision guides rapid hand movements, thereby enhancing their accuracy and precision. To test this idea, we asked observers to point to a briefly presented target (110 ms). We measured the impact of visual information on endpoint precision by using a shutter to close off view of the hand 50, 110 and 250 ms into the reach. We found that precision was degraded if the view of the hand was restricted at any time during the reach, despite the fact that the target disappeared long before the reach was completed. We therefore conclude that vision keeps the hand on the planned trajectory. We then investigated the effects of a perturbation of target position during the reach. For these experiments, the target remained visible until the reach was completed. The target position was shifted at 110, 180 or 250 ms into the reach. Early shifts in target position were easily compensated for, but late shifts led to a shift in the mean position of the endpoints; observers pointed to the center of the two locations, as a kind of best bet on the position of the target. Visual information is used to guide the hand throughout a reach and has a significant impact on endpoint precision. PMID:17109109

  19. Challenges assessing clinical endpoints in early Huntington disease

    PubMed Central

    Paulsen, Jane S.; Wang, Chiachi; Duff, Kevin; Barker, Roger; Nance, Martha; Beglinger, Leigh; Moser, David; Williams, Janet K.; Simpson, Sheila; Langbehn, Douglas; van Kammen, Daniel P.

    2010-01-01

    The primary aim of this study was to evaluate the current accepted standard clinical endpoint for the earliest-studied HD participants likely to be recruited into clinical trials. Since the advent of genetic testing for HD, it is possible to identify gene carriers prior to the diagnosis of disease, which opens up the possibility of clinical trials of disease-modifying treatments in clinically asymptomatic persons. Current accepted standard clinical endpoints were examined as part of a multi-national, 32-site, longitudinal, observational study of 786 research participants currently in the HD prodrome (gene-positive but not clinically diagnosed). Clinical signs and symptoms were used to prospectively predict functional loss as assessed by current accepted standard endpoints over 8 years of follow up. Functional capacity measures were not sensitive for HD in the prodrome; over 88% scored at ceiling. Prospective evaluation revealed that the first functional loss was in their accustomed work. In a survival analysis, motor, cognitive, and psychiatric measures were all predictors of job change. To our knowledge, this is the first prospective study ever conducted on the emergence of functional loss secondary to brain disease. We conclude that future clinical trials designed for very early disease will require the development of new and more sensitive measures of real-life function. PMID:20623772

  20. Challenges assessing clinical endpoints in early Huntington disease.

    PubMed

    Paulsen, Jane S; Wang, Chiachi; Duff, Kevin; Barker, Roger; Nance, Martha; Beglinger, Leigh; Moser, David; Williams, Janet K; Simpson, Sheila; Langbehn, Douglas; van Kammen, Daniel P

    2010-11-15

    The basic aim of this study was to evaluate the current accepted standard clinical endpoint for the earliest-studied HD participants likely to be recruited into clinical trials. As the advent of genetic testing for HD, it is possible to identify gene carriers before the diagnosis of disease, which opens up the possibility of clinical trials of disease-modifying treatments in clinically asymptomatic persons. Current accepted standard clinical endpoints were examined as part of a multinational, 32-site, longitudinal, observational study of 786 research participants currently in the HD prodrome (gene-positive but not clinically diagnosed). Clinical signs and symptoms were used to prospectively predict functional loss as assessed by current accepted standard endpoints over 8 years of follow-up. Functional capacity measures were not sensitive for HD in the prodrome; over 88% scored at ceiling. Prospective evaluation revealed that the first functional loss was in their accustomed work. In a survival analysis, motor, cognitive, and psychiatric measures were all predictors of job change. To our knowledge, this is the first prospective study ever conducted on the emergence of functional loss secondary to brain disease. We conclude that future clinical trials designed for very early disease will require the development of new and more sensitive measures of real-life function. PMID:20623772

  1. Mechanotransduction in Embryonic Vascular Development

    PubMed Central

    Roman, Beth L.; Pekkan, Kerem

    2015-01-01

    A plethora of biochemical signals provides spatial and temporal cues that carefully orchestrate the complex process of vertebrate embryonic development. The embryonic vasculature develops not only in the context of these biochemical cues, but also in the context of the biomechanical forces imparted by blood flow. In the mature vasculature, different blood flow regimes induce distinct genetic programs, and significant progress has been made toward understanding how these forces are perceived by endothelial cells and transduced into biochemical signals. However, it cannot be assumed that paradigms that govern the mature vasculature are pertinent to the developing embryonic vasculature. The embryonic vasculature can respond to the mechanical forces of blood flow, and these responses are critical in vascular remodeling, certain aspects of sprouting angiogenesis, and maintenance of arterial-venous identity. Here, we review data regarding mechanistic aspects of endothelial cell mechanotransduction, with a focus on the response to shear stress, and elaborate upon the multifarious effects of shear stress on the embryonic vasculature. In addition, we discuss emerging predictive vascular growth models and highlight the prospect of combining signaling pathway information with computational modeling. We assert that correlation of precise measurements of hemodynamic parameters with effects on endothelial cell gene expression and cell behavior is required for fully understanding how blood flow-induced loading governs normal vascular development and shapes congenital cardiovascular abnormalities. PMID:22744845

  2. Multiple roles of Activin/Nodal, bone morphogenetic protein, fibroblast growth factor and Wnt/β-catenin signalling in the anterior neural patterning of adherent human embryonic stem cell cultures

    PubMed Central

    Lupo, Giuseppe; Novorol, Claire; Smith, Joseph R.; Vallier, Ludovic; Miranda, Elena; Alexander, Morgan; Biagioni, Stefano; Pedersen, Roger A.; Harris, William A.

    2013-01-01

    Several studies have successfully produced a variety of neural cell types from human embryonic stem cells (hESCs), but there has been limited systematic analysis of how different regional identities are established using well-defined differentiation conditions. We have used adherent, chemically defined cultures to analyse the roles of Activin/Nodal, bone morphogenetic protein (BMP), fibroblast growth factor (FGF) and Wnt/β-catenin signalling in neural induction, anteroposterior patterning and eye field specification in hESCs. We show that either BMP inhibition or activation of FGF signalling is required for effective neural induction, but these two pathways have distinct outcomes on rostrocaudal patterning. While BMP inhibition leads to specification of forebrain/midbrain positional identities, FGF-dependent neural induction is associated with strong posteriorization towards hindbrain/spinal cord fates. We also demonstrate that Wnt/β-catenin signalling is activated during neural induction and promotes acquisition of neural fates posterior to forebrain. Therefore, inhibition of this pathway is needed for efficient forebrain specification. Finally, we provide evidence that the levels of Activin/Nodal and BMP signalling have a marked influence on further forebrain patterning and that constitutive inhibition of these pathways represses expression of eye field genes. These results show that the key mechanisms controlling neural patterning in model vertebrate species are preserved in adherent, chemically defined hESC cultures and reveal new insights into the signals regulating eye field specification. PMID:23576785

  3. Multiple roles of Activin/Nodal, bone morphogenetic protein, fibroblast growth factor and Wnt/β-catenin signalling in the anterior neural patterning of adherent human embryonic stem cell cultures.

    PubMed

    Lupo, Giuseppe; Novorol, Claire; Smith, Joseph R; Vallier, Ludovic; Miranda, Elena; Alexander, Morgan; Biagioni, Stefano; Pedersen, Roger A; Harris, William A

    2013-04-01

    Several studies have successfully produced a variety of neural cell types from human embryonic stem cells (hESCs), but there has been limited systematic analysis of how different regional identities are established using well-defined differentiation conditions. We have used adherent, chemically defined cultures to analyse the roles of Activin/Nodal, bone morphogenetic protein (BMP), fibroblast growth factor (FGF) and Wnt/β-catenin signalling in neural induction, anteroposterior patterning and eye field specification in hESCs. We show that either BMP inhibition or activation of FGF signalling is required for effective neural induction, but these two pathways have distinct outcomes on rostrocaudal patterning. While BMP inhibition leads to specification of forebrain/midbrain positional identities, FGF-dependent neural induction is associated with strong posteriorization towards hindbrain/spinal cord fates. We also demonstrate that Wnt/β-catenin signalling is activated during neural induction and promotes acquisition of neural fates posterior to forebrain. Therefore, inhibition of this pathway is needed for efficient forebrain specification. Finally, we provide evidence that the levels of Activin/Nodal and BMP signalling have a marked influence on further forebrain patterning and that constitutive inhibition of these pathways represses expression of eye field genes. These results show that the key mechanisms controlling neural patterning in model vertebrate species are preserved in adherent, chemically defined hESC cultures and reveal new insights into the signals regulating eye field specification. PMID:23576785

  4. Nucleotide Excision Repair Is Not Induced in Human Embryonic Lung Fibroblasts Treated with Environmental Pollutants

    PubMed Central

    Rossner, Pavel; Spatova, Milada; Rossnerova, Andrea; Libalova, Helena; Schmuczerova, Jana; Milcova, Alena; Topinka, Jan; Sram, Radim J.

    2013-01-01

    The cellular response to genotoxic treatment depends on the cell line used. Although tumor cell lines are widely used for genotoxicity tests, the interpretation of the results may be potentially hampered by changes in cellular processes caused by malignant transformation. In our study we used normal human embryonic lung fibroblasts (HEL12469 cells) and tested their response to treatment with benzo[a]pyrene (B[a]P) and extractable organic matter (EOM) from ambient air particles <2.5 µm (PM2.5) collected in two Czech cities differing in levels and sources of air pollution. We analyzed multiple endpoints associated with exposure to polycyclic aromatic hydrocarbons (PAHs) including the levels of bulky DNA adducts and the nucleotide excision repair (NER) response [expression of XPE, XPC and XPA genes on the level of mRNA and proteins, unscheduled DNA synthesis (UDS)]. EOMs were collected in the winter and summer of 2011 in two Czech cities with different levels and sources of air pollution. The effects of the studied compounds were analyzed in the presence (+S9) and absence (–S9) of the rat liver microsomal S9 fraction. The levels of bulky DNA adducts were highest after treatment with B[a]P, followed by winter EOMs; their induction by summer EOMs was weak. The induction of both mRNA and protein expression was observed, with the most pronounced effects after treatment with B[a]P (–S9); the response induced by EOMs from both cities and seasons was substantially weaker. The expression of DNA repair genes was not accompanied by the induction of UDS activity. In summary, our results indicate that the tested compounds induced low levels of DNA damage and affected the expression of NER genes; however, nucleotide excision repair was not induced. PMID:23894430

  5. Clinical research and methodology: What usage and what hierarchical order for secondary endpoints?

    PubMed

    Laporte, Silvy; Diviné, Marine; Girault, Danièle

    2016-02-01

    In a randomised clinical trial, when the result of the primary endpoint shows a significant benefit, the secondary endpoints are scrutinised to identify additional effects of the treatment. However, this approach entails a risk of concluding that there is a benefit for one of these endpoints when such benefit does not exist (inflation of type I error risk). There are mainly two methods used to control the risk of drawing erroneous conclusions for secondary endpoints. The first method consists of distributing the risk over several co-primary endpoints, so as to maintain an overall risk of 5%. The second is the hierarchical test procedure, which consists of first establishing a hierarchy of the endpoints, then evaluating each endpoint in succession according to this hierarchy while the endpoints continue to show statistical significance. This simple method makes it possible to show the additional advantages of treatments and to identify the factors that differentiate them. PMID:27080628

  6. Endpoint-based parallel data processing in a parallel active messaging interface of a parallel computer

    DOEpatents

    Archer, Charles J; Blocksome, Michael E; Ratterman, Joseph D; Smith, Brian E

    2014-02-11

    Endpoint-based parallel data processing in a parallel active messaging interface ('PAMI') of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes coupled for data communications through the PAMI, including establishing a data communications geometry, the geometry specifying, for tasks representing processes of execution of the parallel application, a set of endpoints that are used in collective operations of the PAMI including a plurality of endpoints for one of the tasks; receiving in endpoints of the geometry an instruction for a collective operation; and executing the instruction for a collective opeartion through the endpoints in dependence upon the geometry, including dividing data communications operations among the plurality of endpoints for one of the tasks.

  7. Endpoint-based parallel data processing in a parallel active messaging interface of a parallel computer

    DOEpatents

    Archer, Charles J.; Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

    2014-08-12

    Endpoint-based parallel data processing in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints, each endpoint including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task, the compute nodes coupled for data communications through the PAMI, including establishing a data communications geometry, the geometry specifying, for tasks representing processes of execution of the parallel application, a set of endpoints that are used in collective operations of the PAMI including a plurality of endpoints for one of the tasks; receiving in endpoints of the geometry an instruction for a collective operation; and executing the instruction for a collective operation through the endpoints in dependence upon the geometry, including dividing data communications operations among the plurality of endpoints for one of the tasks.

  8. Semiparametric regression for the weighted composite endpoint of recurrent and terminal events.

    PubMed

    Mao, Lu; Lin, D Y

    2016-04-01

    Recurrent event data are commonly encountered in clinical and epidemiological studies. A major complication arises when recurrent events are terminated by death. To assess the overall effects of covariates on the two types of events, we define a weighted composite endpoint as the cumulative number of recurrent and terminal events properly weighted by the relative severity of each event. We propose a semiparametric proportional rates model which specifies that the (possibly time-varying) covariates have multiplicative effects on the rate function of the weighted composite endpoint while leaving the form of the rate function and the dependence among recurrent and terminal events completely unspecified. We construct appropriate estimators for the regression parameters and the cumulative frequency function. We show that the estimators are consistent and asymptotically normal with variances that can be consistently estimated. We also develop graphical and numerical procedures for checking the adequacy of the model. We then demonstrate the usefulness of the proposed methods in simulation studies. Finally, we provide an application to a major cardiovascular clinical trial. PMID:26668069

  9. Patient-specific dosimetric endpoints based treatment plan quality control in radiotherapy

    NASA Astrophysics Data System (ADS)

    Song, Ting; Staub, David; Chen, Mingli; Lu, Weiguo; Tian, Zhen; Jia, Xun; Li, Yongbao; Zhou, Linghong; Jiang, Steve B.; Gu, Xuejun

    2015-11-01

    In intensity modulated radiotherapy (IMRT), the optimal plan for each patient is specific due to unique patient anatomy. To achieve such a plan, patient-specific dosimetric goals reflecting each patient’s unique anatomy should be defined and adopted in the treatment planning procedure for plan quality control. This study is to develop such a personalized treatment plan quality control tool by predicting patient-specific dosimetric endpoints (DEs). The incorporation of patient specific DEs is realized by a multi-OAR geometry-dosimetry model, capable of predicting optimal DEs based on the individual patient’s geometry. The overall quality of a treatment plan is then judged with a numerical treatment plan quality indicator and characterized as optimal or suboptimal. Taking advantage of clinically available prostate volumetric modulated arc therapy (VMAT) treatment plans, we built and evaluated our proposed plan quality control tool. Using our developed tool, six of twenty evaluated plans were identified as sub-optimal plans. After plan re-optimization, these suboptimal plans achieved better OAR dose sparing without sacrificing the PTV coverage, and the dosimetric endpoints of the re-optimized plans agreed well with the model predicted values, which validate the predictability of the proposed tool. In conclusion, the developed tool is able to accurately predict optimally achievable DEs of multiple OARs, identify suboptimal plans, and guide plan optimization. It is a useful tool for achieving patient-specific treatment plan quality control.

  10. INDIVIDUALS VERSUS ORGANISMS VERSUS POPULATIONS IN THE DEFINITION OF ECOLOGICAL ASSESSMENT ENDPOINTS

    EPA Science Inventory

    The choice of endpoints for ecological risk assessments can be controversial, and some ecologists dismiss endpoints below the population level as irrelevant. This paper attempts to clarify the concept of assessment endpoints and what is meant by organismal or population attri...

  11. 40 CFR Appendix A to Part 68 - Table of Toxic Endpoints

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 16 2013-07-01 2013-07-01 false Table of Toxic Endpoints A Appendix A to Part 68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Endpoints CAS No. Chemical name Toxic endpoint (mg/L) 107-02-8 Acrolein 0.0011 107-13-1 Acrylonitrile...

  12. 40 CFR Appendix A to Part 68 - Table of Toxic Endpoints

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Table of Toxic Endpoints A Appendix A to Part 68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Endpoints CAS No. Chemical name Toxic endpoint (mg/L) 107-02-8 Acrolein 0.0011 107-13-1 Acrylonitrile...

  13. 40 CFR Appendix A to Part 68 - Table of Toxic Endpoints

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 16 2012-07-01 2012-07-01 false Table of Toxic Endpoints A Appendix A to Part 68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Endpoints CAS No. Chemical name Toxic endpoint (mg/L) 107-02-8 Acrolein 0.0011 107-13-1 Acrylonitrile...

  14. 40 CFR Appendix A to Part 68 - Table of Toxic Endpoints

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 16 2014-07-01 2014-07-01 false Table of Toxic Endpoints A Appendix A to Part 68 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... Endpoints CAS No. Chemical name Toxic endpoint (mg/L) 107-02-8 Acrolein 0.0011 107-13-1 Acrylonitrile...

  15. 78 FR 49530 - Gastroenterology Regulatory Endpoints and the Advancement of Therapeutics; Public Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-14

    ... HUMAN SERVICES Food and Drug Administration Gastroenterology Regulatory Endpoints and the Advancement of... workshop entitled ``Gastroenterology Regulatory Endpoints and the Advancement of Therapeutics (GREAT II... Health. The purpose of this workshop is to provide a forum to consider issues related to endpoints...

  16. Mechanochemical actuators of embryonic epithelial contractility.

    PubMed

    Kim, YongTae; Hazar, Melis; Vijayraghavan, Deepthi S; Song, Jiho; Jackson, Timothy R; Joshi, Sagar D; Messner, William C; Davidson, Lance A; LeDuc, Philip R

    2014-10-01

    Spatiotemporal regulation of cell contractility coordinates cell shape change to construct tissue architecture and ultimately directs the morphology and function of the organism. Here we show that contractility responses to spatially and temporally controlled chemical stimuli depend much more strongly on intercellular mechanical connections than on biochemical cues in both stimulated tissues and adjacent cells. We investigate how the cell contractility is triggered within an embryonic epithelial sheet by local ligand stimulation and coordinates a long-range contraction response. Our custom microfluidic control system allows spatiotemporally controlled stimulation with extracellular ATP, which results in locally distinct contractility followed by mechanical strain pattern formation. The stimulation-response circuit exposed here provides a better understanding of how morphogenetic processes integrate responses to stimulation and how intercellular responses are transmitted across multiple cells. These findings may enable one to create a biological actuator that actively drives morphogenesis. PMID:25246549

  17. Dynamical realization of end-point memory in consolidated materials

    NASA Astrophysics Data System (ADS)

    Vakhnenko, Vyacheslav O.; Vakhnenko, Oleksiy O.; TenCate, James A.; Shankland, Thomas J.

    2006-05-01

    Starting with a soft-ratchet model of slow dynamics in nonlinear resonant response of sedimentary rocks we predict the dynamical realization of end-point memory in resonating bar experiments with a cyclic frequency protocol. The effect we describe and simulate is defined as the memory of previous maximum amplitude of alternating stress and manifested in the form of small hysteretic loops inside the big hysteretic loop on the resonance curve. It is most clearly pronounced in the vicinity of bar resonant frequency. These theoretical findings are confirmed experimentally.

  18. Exploring a possible origin of the QCD critical endpoint

    SciTech Connect

    Bugaev, K. A. Petrov, V. K. Zinovjev, G. M.

    2013-03-15

    We develop a new model of the QCD critical endpoint by matching the deconfinement phase transition line of quark-gluon bags with the similar line at which the bag surface tension coefficient vanishes. Unlike all previous studies of such models the deconfined phase in our approach is defined not by an essential singularity of the isobaric partition function but its simple pole. As an unexpected result we find out that the first-order phase transition which is usually defined by a discontinuity of the first derivative of the bag system pressure results from a discontinuity of the derivative of surface tension coefficient of quark-gluon bags.

  19. ASPREE Cancer Endpoints Study | Division of Cancer Prevention

    Cancer.gov

    The ASPREE Cancer Endpoint Study (ACES), an ancillary study of the ASPirin in the Prevention of Events in the Elderly (ASPREE) Study, will allow for the examination of the effect of daily low-dose aspirin (100 mg) compared to placebo, on specific DNA biomarkers and selected specific incident and recurrent cancer and metastases. The establishment of this ACES biobank will allow for the exploration of DNA-related molecular mechanisms of aspirin's protective effect against cancer, cancer associated mortality and metastases, using blood or saliva DNA specimens, urine, and tumor tissue. |

  20. Impact of copula directional specification on multi-trial evaluation of surrogate endpoints

    PubMed Central

    Renfro, Lindsay A.; Shang, Hongwei; Sargent, Daniel J.

    2014-01-01

    Evaluation of surrogate endpoints using patient-level data from multiple trials is the gold standard, where multi-trial copula models are used to quantify both patient-level and trial-level surrogacy. While limited consideration has been given in the literature to copula choice (e.g., Clayton), no prior consideration has been given to direction of implementation (via survival versus distribution functions). We demonstrate that evenwith the “correct” copula family, directional misspecification leads to biased estimates of patient-level and trial-level surrogacy. We illustrate with a simulation study and a re-analysis of disease-free survival as a surrogate for overall survival in early stage colon cancer. PMID:24905465

  1. Immediate skin responses to laser and light treatments: Warning endpoints: How to avoid side effects.

    PubMed

    Wanner, Molly; Sakamoto, Fernanda H; Avram, Mathew M; Anderson, R Rox

    2016-05-01

    Lasers are versatile, commonly used treatment tools in dermatology. While it is tempting to follow manufacturer's guidelines or other "recipes" for laser treatment, this approach alone can be a recipe for disaster. Specific and immediate skin responses or endpoints exist and are clinically useful because they correlate with underlying mechanisms that are either desirable (ie, therapeutic), undesirable (ie, warning signs of injury or side effects), or incidental. The observation of clinical endpoints is a safe and reliable guide for appropriate treatment. This article presents the warning endpoints during specific dermatologic laser treatments, and the accompanying article presents the therapeutic endpoints, their underlying mechanisms, and the utility of these endpoints. PMID:27085227

  2. Critical endpoint for deconfinement in matrix and other effective models

    NASA Astrophysics Data System (ADS)

    Kashiwa, Kouji; Pisarski, Robert D.; Skokov, Vladimir V.

    2012-06-01

    We consider the position of the deconfining critical endpoint, where the first order transition for deconfinement is washed out by the presence of massive, dynamical quarks. We use an effective matrix model, employed previously to analyze the transition in the pure glue theory. If the parameters of the pure glue theory are unaffected by the presence of dynamical quarks, and if the quarks only contribute perturbatively, then for three colors and three degenerate quark flavors this quark mass is very heavy, mde˜2.5GeV, while the critical temperature Tde barely changes, ˜1% below that in the pure glue theory. The location of the deconfining critical endpoint is a sensitive test to differentiate between effective models. For example, models with a logarithmic potential for the Polyakov loop give much smaller values of the quark mass, mde˜1GeV, and a large shift in Tde˜10% lower than that in the pure glue theory.

  3. Biomarkers and cognitive endpoints to optimize trials in Alzheimer's disease

    PubMed Central

    Insel, Philip S; Mattsson, Niklas; Mackin, R Scott; Kornak, John; Nosheny, Rachel; Tosun-Turgut, Duygu; Donohue, Michael C; Aisen, Paul S; Weiner, Michael W

    2015-01-01

    Objective To find the combination of candidate biomarkers and cognitive endpoints to maximize statistical power and minimize cost of clinical trials of healthy elders at risk for cognitive decline due to Alzheimer's disease. Methods Four-hundred and twelve cognitively normal participants were followed over 7 years. Nonlinear methods were used to estimate the longitudinal trajectories of several cognitive outcomes including delayed memory recall, executive function, processing speed, and several cognitive composites by subgroups selected on the basis of biomarkers, including APOE-ε4 allele carriers, cerebrospinal fluid biomarkers (Aβ42, total tau, and phosphorylated tau), and those with small hippocampi. Results Derived cognitive composites combining Alzheimer's Disease Assessment Scale (ADAS)-cog scores with additional delayed memory recall and executive function components captured decline more robustly across biomarker groups than any measure of a single cognitive domain or ADAS-cog alone. Substantial increases in power resulted when including only participants positive for three or more biomarkers in simulations of clinical trials. Interpretation Clinical trial power may be improved by selecting participants on the basis of amyloid and neurodegeneration biomarkers and carefully tailoring primary cognitive endpoints to reflect the expected decline specific to these individuals. PMID:26000325

  4. Population-scale assessment endpoints in ecological risk assessment. Part 1: Reflections of stakeholder values.

    PubMed

    Landis, Wayne G

    2006-01-01

    The selection of appropriate assessment endpoints is a basic element of an ecological risk assessment, especially at regional or watershed scales. Because ecological services often are tied to specific species, the risk to populations is a critical endpoint and feature of ecological risk assessments. The first item is a discussion of the replacement of population-level risk assessment with the construct of a population-scale assessment endpoint. Next, the criteria that are currently used for assessment endpoints are reviewed and evaluated for utility in an ecological risk assessment. Following this examination, assessment endpoints from a number of regional-scale ecological risk assessments are compared. The outcome of this evaluation is that population-scale assessment endpoints are important expressions of the valued components of ecological structures. Finally, a few recommendations for the selection of assessment endpoints at a population scale are listed. PMID:16640323

  5. 21 CFR 314.510 - Approval based on a surrogate endpoint or on an effect on a clinical endpoint other than survival...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... effect on a clinical endpoint other than survival or irreversible morbidity. 314.510 Section 314.510 Food... a clinical endpoint other than survival or irreversible morbidity. FDA may grant marketing approval for a new drug product on the basis of adequate and well-controlled clinical trials establishing...

  6. Surrogate clinical endpoints to predict overall survival in non-small cell lung cancer trials—are we in a new era?

    PubMed Central

    Wang, Xiaofei; Ready, Neal E.

    2015-01-01

    Surrogate endpoints for clinical trials in oncology offer an alternative metric for measuring clinical benefit, allowing for shorter trial duration, smaller patient cohorts, and single arm design. The correlation of surrogate endpoints with overall survival (OS) in therapeutic studies is a central consideration to their validity. The Food and Drug Administration (FDA) recently published an analysis of fourteen clinical trials in advanced non-small cell lung cancer (NSCLC), and discovered a strong association between response rate and progression free survival. Furthermore, a correlation between response rate and OS is demonstrated when analyzing the experimental treatment arm separately, minimizing bias from patient crossover. We also highlight multiple, important considerations when using response as an endpoint in clinical trials involving NSCLC patients. PMID:26798592

  7. Transgenerational Epigenetic Programming of the Embryonic Testis Transcriptome

    PubMed Central

    Anway, Matthew D.; Rekow, Stephen S.; Skinner, Michael K.

    2008-01-01

    Embryonic exposure to the endocrine disruptor vinclozolin during gonadal sex determination appears to promote an epigenetic reprogramming of the male germ-line that is associated with transgenerational adult onset disease states. Transgenerational effects on the embryonic day 16 (E16) testis demonstrated reproducible changes in the testis transcriptome for multiple generations (F1-F3). The expression of 196 genes were found to be influenced, with the majority of gene expression being decreased or silenced. Dramatic changes in the gene expression of methyltransferases during gonadal sex determination were observed in the F1 and F2 vinclozolin generation (E16) embryonic testis, but the majority returned to control generation levels by the F3 generation. The most dramatic effects were on the germ-line associated Dnmt3A and Dnmt3L isoforms. Observations demonstrate that an embryonic exposure to vinclozolin appears to promote an epigenetic reprogramming of the male germ-line that correlates with transgenerational alterations in the testis transcriptome in subsequent generations. PMID:18042343

  8. Quantitative In Vivo Imaging of Embryonic Development: Opportunities and Challenges

    PubMed Central

    Gregg, Chelsea L.; Butcher, Jonathan T.

    2013-01-01

    Animal models are critically important for mechanistic understanding of embryonic morphogenesis. For decades, visualizing these rapid and complex multidimensional events has relied on projection images and thin section reconstructions. While much insight has been gained, fixed tissue specimens offer limited information on dynamic processes that are essential for tissue assembly and organ patterning. Quantitative imaging is required to unlock the important basic science and clinically relevant secrets that remain hidden. Recent advances in live imaging technology have enabled quantitative longitudinal analysis of embryonic morphogenesis at multiple length and time scales. Four different imaging modalities are currently being used to monitor embryonic morphogenesis: optical, ultrasound, magnetic resonance imaging (MRI), and micro-computed tomography (micro-CT). Each has its advantages and limitations with respect to spatial resolution, depth of field, scanning speed, and tissue contrast. In addition, new processing tools have been developed to enhance live imaging capabilities. In this review, we analyze each type of imaging source and its use in quantitative study of embryonic morphogenesis in small animal models. We describe the physics behind their function, identify some examples in which the modality has revealed new quantitative insights, and then conclude with a discussion of new research directions with live imaging. PMID:22695188

  9. Quantitative in vivo imaging of embryonic development: opportunities and challenges.

    PubMed

    Gregg, Chelsea L; Butcher, Jonathan T

    2012-07-01

    Animal models are critically important for a mechanistic understanding of embryonic morphogenesis. For decades, visualizing these rapid and complex multidimensional events has relied on projection images and thin section reconstructions. While much insight has been gained, fixed tissue specimens offer limited information on dynamic processes that are essential for tissue assembly and organ patterning. Quantitative imaging is required to unlock the important basic science and clinically relevant secrets that remain hidden. Recent advances in live imaging technology have enabled quantitative longitudinal analysis of embryonic morphogenesis at multiple length and time scales. Four different imaging modalities are currently being used to monitor embryonic morphogenesis: optical, ultrasound, magnetic resonance imaging (MRI), and micro-computed tomography (micro-CT). Each has its advantages and limitations with respect to spatial resolution, depth of field, scanning speed, and tissue contrast. In addition, new processing tools have been developed to enhance live imaging capabilities. In this review, we analyze each type of imaging source and its use in quantitative study of embryonic morphogenesis in small animal models. We describe the physics behind their function, identify some examples in which the modality has revealed new quantitative insights, and then conclude with a discussion of new research directions with live imaging. PMID:22695188

  10. Trends in Utilization of Surrogate Endpoints in Contemporary Cardiovascular Clinical Trials.

    PubMed

    Patel, Ravi B; Vaduganathan, Muthiah; Samman-Tahhan, Ayman; Kalogeropoulos, Andreas P; Georgiopoulou, Vasiliki V; Fonarow, Gregg C; Gheorghiade, Mihai; Butler, Javed

    2016-06-01

    Surrogate endpoints facilitate trial efficiency but are variably linked to clinical outcomes, and limited data are available exploring their utilization in cardiovascular clinical trials over time. We abstracted data regarding primary clinical, intermediate, and surrogate endpoints from all phase II to IV cardiovascular clinical trials from 2001 to 2012 published in the 8 highest Web of Science impact factor journals. Two investigators independently classified the type of primary endpoint. Of the 1,224 trials evaluated, 677 (55.3%) primary endpoints were clinical, 165 (13.5%) intermediate, and 382 (31.2%) surrogate. The relative proportions of these endpoints remained constant over time (p = 0.98). Trials using surrogate endpoints were smaller (187 vs 1,028 patients) and enrolled patients more expeditiously (1.4 vs 0.9 patients per site per month) compared with trials using clinical endpoints (p <0.001 for both comparisons). Surrogate endpoint trials were independently more likely to meet their primary endpoint compared to trials with clinical endpoints (adjusted odds ratio 1.56, 95% CI 1.05 to 2.34; p = 0.03). Rates of positive results in clinical endpoint trials have decreased over time from 66.1% in 2001 to 2003 to 47.2% in 2010 to 2012 (p = 0.001), whereas these rates have remained stable over the same period for surrogate (72.0% to 69.3%, p = 0.27) and intermediate endpoints (74.4% to 71.4%, p = 0.98). In conclusion, approximately a third of contemporary cardiovascular trials use surrogate endpoints. These trials are completed more expeditiously and are more likely to meet their primary outcomes. The overall scientific contribution of these surrogate endpoint trials requires further attention given their variable association with definitive outcomes. PMID:27085935

  11. The fungicide propiconazole interferes with embryonic development of the crustacean Daphnia magna.

    PubMed

    Kast-Hutcheson, K; Rider, C V; LeBlanc, G A

    2001-03-01

    Propiconazole is a fungicide used in a variety of agricultural applications. Preliminary studies had suggested that embryos of the crustacean Daphnia magna are particularly susceptible to the toxicity of this chemical. The goals of the present study were to define endpoints of daphnid embryonic development that could be routinely used to assess the embryo toxicity of chemicals and to characterize definitively the embryo toxicity of propiconazole to daphnids. Daphnid embryonic development was characterized into six readily distinguishable stages based on the degree of tissue differentiation. Embryonic development could be monitored either in the brood chamber of the maternal organism or using embryos removed from the brood chamber and incubated ex vivo. Standard toxicity assessment revealed that propiconazole elicited no significant adverse effects on daphnid survival or fecundity during a 21-d exposure to concentrations as high as 0.25 mg/L. Exposure to 0.25 mg/L propiconazole, however, caused a significant incidence of developmental abnormalities and embryonic death. Abnormalities were consistent with developmental arrest at later stages of embryonic maturation. Propiconazole elicited a steep concentration-response curve with respect to embryo toxicity, with a 10% and a 90% incidence of embryo toxicity measured at 0.50 and 0.82 mg/L, respectively. Direct exposure of embryos to propiconazole resulted in toxicity, though the incidence and characteristics of developmental abnormalities were not consistent with that observed during chronic exposures. However, maternal exposure to propiconazole followed by transfer of early embryos to propiconazole-free media resulted in embryo toxicity consistent with that observed during chronic exposure. These results indicate that propiconazole interferes with the later stages of daphnid embryonic development, and that this toxicity is manifested largely via maternal exposure to the fungicide. PMID:11349850

  12. Embryonic development during chronic acceleration

    NASA Technical Reports Server (NTRS)

    Smith, A. H.; Abbott, U. K.

    1982-01-01

    Experiments carried out on chicken eggs indicate that the embryo is affected during very early development, especially over the first four days, and during hatching. In the first four days, the brain develops as well as the anlage for all other organs. In addition, the heart commences to function and the extraembryonic membranes that compartmentalize the egg contents form. The latter require an appreciable extension and folding of tissue which may be disrupted by the mechanical load. Observations of embryonic abnormalities that occur during chronic acceleration suggest an inhibition of development of the axial skeleton, which is rarely seen otherwise, a general retardation of embryonic growth, and circulatory problems. The final stages of development (after 18 days) involve the uptake of fluids, the transition to aerial respiration, and the reorientation of the embryo into a normal hatching position. At 4 G mortality is very high during this period, with a majority of embryos failing to reorient into the normal hatching position.

  13. Embryonic Heart Progenitors and Cardiogenesis

    PubMed Central

    Brade, Thomas; Pane, Luna S.; Moretti, Alessandra; Chien, Kenneth R.; Laugwitz, Karl-Ludwig

    2013-01-01

    The mammalian heart is a highly specialized organ, comprised of many different cell types arising from distinct embryonic progenitor populations during cardiogenesis. Three precursor populations have been identified to contribute to different myocytic and nonmyocytic cell lineages of the heart: cardiogenic mesoderm cells (CMC), the proepicardium (PE), and cardiac neural crest cells (CNCCs). This review will focus on molecular cues necessary for proper induction, expansion, and lineage-specific differentiation of these progenitor populations during cardiac development in vivo. Moreover, we will briefly discuss how the knowledge gained on embryonic heart progenitor biology can be used to develop novel therapeutic strategies for the management of congenital heart disease as well as for improvement of cardiac function in ischemic heart disease. PMID:24086063

  14. Diversity and Complexity in Chromatin Recognition by TFII-I Transcription Factors in Pluripotent Embryonic Stem Cells and Embryonic Tissues

    PubMed Central

    Makeyev, Aleksandr V.; Enkhmandakh, Badam; Hong, Seung-Hyun; Joshi, Pujan; Shin, Dong-Guk; Bayarsaihan, Dashzeveg

    2012-01-01

    GTF2I and GTF2IRD1 encode a family of closely related transcription factors TFII-I and BEN critical in embryonic development. Both genes are deleted in Williams-Beuren syndrome, a complex genetic disorder associated with neurocognitive, craniofacial, dental and skeletal abnormalities. Although genome-wide promoter analysis has revealed the existence of multiple TFII-I binding sites in embryonic stem cells (ESCs), there was no correlation between TFII-I occupancy and gene expression. Surprisingly, TFII-I recognizes the promoter sequences enriched for H3K4me3/K27me3 bivalent domain, an epigenetic signature of developmentally important genes. Moreover, we discovered significant differences in the association between TFII-I and BEN with the cis-regulatory elements in ESCs and embryonic craniofacial tissues. Our data indicate that in embryonic tissues BEN, but not the highly homologous TFII-I, is primarily recruited to target gene promoters. We propose a “feed-forward model” of gene regulation to explain the specificity of promoter recognition by TFII-I factors in eukaryotic cells. PMID:22970219

  15. Use of behavioral endpoints in natural resource damage assessment

    SciTech Connect

    Lipton, J.; Marr, J.

    1994-12-31

    Behavioral effects caused by exposure to hazardous substances can play an important role in Natural Resource Damage Assessment (NRDA) cases. Behavioral avoidance has been recognized as a natural resource injury in the Department of Interior`s NRDA regulations. Behavioral avoidance may be particularly important as an NRDA endpoint because it can occur at exposure concentrations substantially less than lethal concentrations, and can result in the effective loss of aquatic habitat. For example, in a recent NRDA case, laboratory testing demonstrated behavioral avoidance at copper concentrations of 1.2 {micro}g/l and 6 {micro}g/l for rainbow and brown trout, respectively. Other behavioral effects may have similar adverse effects on populations in the wild and may merit inclusion in NRDA injury and restoration studies.

  16. [Endpoints in clinical trials and their relevance for patients].

    PubMed

    Faber, Ulrike

    2010-01-01

    Patient participation, which has been established since 2004, has brought more attention to patients' concerns in healthcare. More and more endpoints in clinical trials are defined with respect to their relevance for patients. But this development has still been found wanting. For important drugs, no evidence-based benefit has been demonstrated in the benefit assessment, which also has become possible since 2004. Furthermore, this assessment has arrived too late for patients who have been medicated for a long time. Healthcare policies, applicants and stakeholders have contributed a lot to the patients' scepticism towards benefit assessments, though, in principle, patients are interested in high evidence levels and reasonable pricing. New drugs are often licensed under less ambitious conditions. Whether this is in the patients' interest needs to be put up for a large-scale, and societal, discussion. PMID:20608257

  17. Are Hemodynamics Surrogate Endpoints in Pulmonary Arterial Hypertension?

    PubMed Central

    Ventetuolo, Corey E.; Gabler, Nicole B.; Fritz, Jason S.; Smith, K. Akaya; Palevsky, Harold I.; Klinger, James R.; Halpern, Scott D.; Kawut, Steven M.

    2014-01-01

    Background While frequently assessed in trials and clinical practice, hemodynamic response to therapy has never been validated as a surrogate endpoint for clinical events in pulmonary arterial hypertension (PAH). Methods and Results We performed a patient-level pooled analysis of four randomized placebo-controlled trials to determine if treatment-induced changes in hemodynamic values at 12 weeks accounted for the relationship between treatment assignment and the probability of early clinical events (death, lung transplantation, atrial septostomy, PAH hospitalization, withdrawal for clinical worsening, escalation in PAH therapy). We included 1119 subjects with PAH. The median (interquartile range) age was 48 (37 – 59), and 23% were men. 656 (59%) received active therapy (101 [15%] iloprost, 118 [18%] sitaxsentan, 204 [31%] sildenafil, and 233 [36%] subcutaneous treprostinil). Active treatment significantly lowered right atrial pressure (RAP), mean pulmonary artery pressure (mPAP), and pulmonary vascular resistance and increased cardiac output and index (p < 0.01 for all). Changes in hemodynamic values (except for RAP and mPAP) were significantly associated with the risk of a clinical event (p ≤ 0.01 for all). While active treatment approximately halved the odds of a clinical event compared to placebo (p < 0.001), changes in hemodynamics accounted for only 1.2 – 13.9% of the overall treatment effect. Conclusions Treatment-induced changes in hemodynamics at 12 weeks only partially explain the impact of therapy on the probability of early clinical events in PAH. These findings suggest that resting hemodynamics are not valid surrogate endpoints for short-term events in PAH clinical trials. PMID:24951771

  18. Mouse handling limits the impact of stress on metabolic endpoints.

    PubMed

    Ghosal, Sriparna; Nunley, Amanda; Mahbod, Parinaz; Lewis, Alfor G; Smith, Eric P; Tong, Jenny; D'Alessio, David A; Herman, James P

    2015-10-15

    Studies focused on end-points that are confounded by stress are best performed under minimally stressful conditions. The objective of this study was to demonstrate the impact of handling designed to reduce animal stress on measurements of glucose tolerance. A cohort of mice (CD1.C57BL/6) naïve to any specific handling was subjected to either a previously described "cup" handling method, or a "tail-picked" method in which the animals were picked up by the tail (as is common for metabolic studies). Following training, an elevated plus maze (EPM) test was performed followed by measurement of blood glucose and plasma corticosterone. A second cohort (CD1.C57BL/6) was rendered obese by exposure to a high fat diet, handled with either the tail-picked or cup method and subjected to an intraperitoneal glucose tolerance test. A third cohort of C57BL/6 mice was exposed to a cup regimen that included a component of massage and was subjected to tests of anxiety-like behavior, glucose homeostasis, and corticosterone secretion. We found that the cup mice showed reduced anxiety-like behaviors in the EPM coupled with a reduction in blood glucose levels compared to mice handled by the tail-picked method. Additionally, cup mice on the high fat diet exhibited improved glucose tolerance compared to tail-picked controls. Finally, we found that the cup/massage group showed lower glucose levels following an overnight fast, and decreased anxiety-like behaviors associated with lower stress-induced plasma corticosterone concentration compared to tail-picked controls. These data demonstrate that application of handling methods that reduce anxiety-like behaviors in mice mitigates the confounding contribution of stress to interpretation of metabolic endpoints (such as glucose tolerance). PMID:26079207

  19. Integrative analysis of the mouse embryonic transcriptome.

    PubMed

    Singh, Amar V; Knudsen, Kenneth B; Knudsen, Thomas B

    2007-01-01

    Monitoring global gene expression provides insight into how genes and regulatory signals work together to guide embryo development. The fields of developmental biology and teratology are now confronted with the need for automated access to a reference library of gene-expression signatures that benchmark programmed (genetic) and adaptive (environmental) regulation of the embryonic transcriptome. Such a library must be constructed from highly-distributed microarray data. Birth Defects Systems Manager (BDSM), an open access knowledge management system, provides custom software to mine public microarray data focused on developmental health and disease. The present study describes tools for seamless data integration in the BDSM library (MetaSample, MetaChip, CIAeasy) using the QueryBDSM module. A field test of the prototype was run using published microarray data series derived from a variety of laboratories, experiments, microarray platforms, organ systems, and developmental stages. The datasets focused on several developing systems in the mouse embryo, including preimplantation stages, heart and nerve development, testis and ovary development, and craniofacial development. Using BDSM data integration tools, a gene-expression signature for 346 genes was resolved that accurately classified samples by organ system and developmental sequence. The module builds a potential for the BDSM approach to decipher a large number developmental processes through comparative bioinformatics analysis of embryological systems at-risk for specific defects, using multiple scenarios to define the range of probabilities leading from molecular phenotype to clinical phenotype. We conclude that an integrative analysis of global gene-expression of the developing embryo can form the foundation for constructing a reference library of signaling pathways and networks for normal and abnormal regulation of the embryonic transcriptome. These tools are available free of charge from the web-site http

  20. Integrative analysis of the mouse embryonic transcriptome

    PubMed Central

    Singh, Amar V; Knudsen, Kenneth B; Knudsen, Thomas B

    2007-01-01

    Monitoring global gene expression provides insight into how genes and regulatory signals work together to guide embryo development. The fields of developmental biology and teratology are now confronted with the need for automated access to a reference library of gene-expression signatures that benchmark programmed (genetic) and adaptive (environmental) regulation of the embryonic transcriptome. Such a library must be constructed from highly-distributed microarray data. Birth Defects Systems Manager (BDSM), an open access knowledge management system, provides custom software to mine public microarray data focused on developmental health and disease. The present study describes tools for seamless data integration in the BDSM library (MetaSample, MetaChip, CIAeasy) using the QueryBDSM module. A field test of the prototype was run using published microarray data series derived from a variety of laboratories, experiments, microarray platforms, organ systems, and developmental stages. The datasets focused on several developing systems in the mouse embryo, including preimplantation stages, heart and nerve development, testis and ovary development, and craniofacial development. Using BDSM data integration tools, a gene-expression signature for 346 genes was resolved that accurately classified samples by organ system and developmental sequence. The module builds a potential for the BDSM approach to decipher a large number developmental processes through comparative bioinformatics analysis of embryological systems at-risk for specific defects, using multiple scenarios to define the range of probabilities leading from molecular phenotype to clinical phenotype. We conclude that an integrative analysis of global gene-expression of the developing embryo can form the foundation for constructing a reference library of signaling pathways and networks for normal and abnormal regulation of the embryonic transcriptome. These tools are available free of charge from the web-site http

  1. Relating suborganismal processes to ecotoxicological and population level endpoints using a bioenergetic model.

    PubMed

    Ananthasubramaniam, Bharath; McCauley, Edward; Gust, Kurt A; Kennedy, Alan J; Muller, Erik B; Perkins, Edward J; Nisbet, Roger M

    2015-09-01

    Ecological effects of environmental stressors are commonly evaluated using organismal or suborganismal data, such as standardized toxicity tests that characterize responses of individuals (e.g., mortality and reproduction) and a rapidly growing body of "omics" data. A key challenge for environmental risk assessment is relating such information to population dynamics. One approach uses dynamic energy budget (DEB) models that relate growth and reproduction of individuals to underlying flows of energy and elemental matter. We hypothesize that suborganismal information identifies DEB parameters that are most likely impacted by a particular stressor and that the DEB model can then project suborganismal effects on life history and population endpoints. We formulate and parameterize a model of growth and reproduction for the water flea Daphnia magna. Our model resembles previous generic bioenergetic models, but has explicit representation of discrete molts, an important feature of Daphnia life history. We test its ability to predict six endpoints commonly used in chronic toxicity studies in specified food environments. With just one adjustable parameter, the model successfully predicts growth and reproduction of individuals from a wide array of experiments performed in multiple laboratories using different clones of D. magna raised on different food sources. Fecundity is the most sensitive endpoint, and there is broad correlation between the sensitivities of fecundity and long-run growth rate, as is desirable for the default metric used in chronic toxicity tests. Under some assumptions, we can combine our DEB model with the Euler-Lotka equation to estimate longrun population growth rates at different food levels. A review of Daphnia gene-expression experiments on the effects of contaminant exposure reveals several connections to model parameters, in particular a general trend of increased transcript expression of genes involved in energy assimilation and utilization at

  2. NPAS1 regulates branching morphogenesis in embryonic lung.

    PubMed

    Levesque, Bernadette M; Zhou, Shutang; Shan, Lin; Johnston, Pamela; Kong, Yanping; Degan, Simone; Sunday, Mary E

    2007-04-01

    Drosophila trachealess (Trl), master regulator of tracheogenesis, has no known functional mammalian homolog. We hypothesized that genes similar to trachealess regulate lung development. Quantitative (Q)RT-PCR and immunostaining were used to determine spatial and temporal patterns of npas1 gene expression in developing murine lung. Immunostaining for alpha-smooth muscle actin demonstrated myofibroblasts, and protein gene product (PGP)9.5 identified neuroendocrine cells. Branching morphogenesis of embryonic lung buds was analyzed in the presence of antisense or sense oligodeoxynucleotides (ODN). Microarray analyses were performed to screen for changes in gene expression in antisense-treated lungs. QRT-PCR was used to validate the altered expression of key genes identified on the microarrays. We demonstrate that npas1 is expressed in murine embryonic lung. npas1 mRNA peaks early at Embryonic Day (E)10.5-E11.5, then drops to low levels. Sequencing verifies the identity of npas1 transcripts in embryonic lung. NPAS1 immunostaining occurs in nuclei of parabronchial mesenchymal cells, especially at the tracheal bifurcation. Arnt, the murine homolog of Tango (the heterodimerization partner for Trl) is also expressed in developing lung but at constant levels. npas1- or arnt-antisense ODN inhibit lung branching morphogenesis, with altered myofibroblast development and increased pulmonary neuroendocrine cells. On microarrays, we identify > 50 known genes down-regulated by npas1-antisense, including multiple genes regulating cell migration and cell differentiation. QRT-PCR confirms significantly decreased expression of the neurogenic genes RBP-Jk and Tle, and three genes involved in muscle development: beta-ig-h3, claudin-11, and myocardin. Npas1 can regulate myofibroblast distribution, branching morphogenesis, and neuroendocrine cell differentiation in murine embryonic lung. PMID:17110583

  3. Additional efficacy endpoints from pivotal natalizumab trials in relapsing-remitting MS.

    PubMed

    Weinstock-Guttman, Bianca; Galetta, Steven L; Giovannoni, Gavin; Havrdova, Eva; Hutchinson, Michael; Kappos, Ludwig; O'Connor, Paul W; Phillips, J Theodore; Polman, Chris; Stuart, William H; Lynn, Frances; Hotermans, Christophe

    2012-05-01

    Standard clinical endpoints in multiple sclerosis (MS) studies, such as disability progression defined by the expanded disability status scale (EDSS) and annualized relapse rate, may not fully reflect all aspects of therapeutic benefit experienced by patients. Pivotal studies showed that natalizumab is effective both as monotherapy (AFFIRM study) and in combination with interferon beta-1a (IFNβ-1a) (SENTINEL study) in patients with relapsing MS. We present AFFIRM and SENTINEL data demonstrating the efficacy of natalizumab on prespecified tertiary endpoints, including extent of confirmed change in EDSS score from baseline, time to sustained progression to EDSS milestone scores, hospitalizations, corticosteroid use, and time to confirmed progression of cognitive deficits. Natalizumab significantly reduced changes in EDSS scores (P < 0.001) and proportion of patients progressing to an EDSS score ≥4.0 (P < 0.001) and ≥6.0 (P = 0.002) compared with placebo. Natalizumab + IFNβ-1a significantly reduced changes in EDSS scores compared with placebo + IFNβ-1a (P = 0.011). Based on 0.5 standard deviation change in paced auditory serial addition test-3 score, natalizumab treatment reduced the risk of confirmed progression of cognitive deficits by 43% compared with placebo (HR 0.57 [95% CI 0.37, 0.89], P = 0.013); however, no significant difference between groups was seen in SENTINEL. Natalizumab, both as monotherapy and in combination with IFNβ-1a, significantly reduced the annualized rate of MS-related hospitalizations (by 64 and 61%, respectively) and the annualized rate of relapses severe enough to require steroid treatment (by 69 and 61%, respectively) compared with placebo and placebo + IFNβ-1a (P < 0.001). These analyses underline beneficial effects of natalizumab therapy in relapsing MS patients. PMID:22008873

  4. End-point Region of the Electron Spectrum in Inclusive Semileptonic Heavy Quark Decay

    SciTech Connect

    Isgur, Nathan

    1992-01-01

    I examine the relationship between the inclusive and sum-over-exclusive-resonances pictures for the electron spectrum of semileptonic heavy quark decay. The analysis shown to that obtained from a free-quark-decay-type model with an endpoint adjusted to the physical endpoint. This conclusion removes the need for nonresonant contributions in the endpoint region and is consistent with arguments that free-quark-decay-type models are, in principle,

  5. Anatomy of an experimental two-link flexible manipulator under end-point control

    NASA Technical Reports Server (NTRS)

    Oakley, Celia M.; Cannon, Robert H., Jr.

    1990-01-01

    The design and experimental implementation of an end-point controller for two-link flexible manipulators are presented. The end-point controller is based on linear quadratic Gaussian (LQG) theory and is shown to exhibit significant improvements in trajectory tracking over a conventional controller design. To understand the behavior of the manipulator structure under end-point control, a strobe sequence illustrating the link deflections during a typical slew maneuver is included.

  6. Multiple comparisons in complex clinical trial designs.

    PubMed

    Hung, H M James; Wang, Sue-Jane

    2013-05-01

    Multiple comparisons have drawn a great deal of attention in evaluation of statistical evidence in clinical trials for regulatory applications. As the clinical trial methodology is increasingly more complex to properly take into consideration many practical factors, the multiple testing paradigm widely employed for regulatory applications may not suffice to interpret the results of an individual trial and of multiple trials. In a large outcome trial, an increasing need of studying more than one dose complicates a proper application of multiple comparison procedures. Additional challenges surface when a special endpoint, such as mortality, may need to be tested with multiple clinical trials combined, especially under group sequential designs. Another interesting question is how to study mortality or morbidity endpoints together with symptomatic endpoints in an efficient way, where the former type of endpoints are often studied in only one single trial but the latter type of endpoints are usually studied in at least two independent trials. This article is devoted to discussion of insufficiency of such a widely used paradigm applying only per-trial based multiple comparison procedures and to expand the utility of the procedures to such complex trial designs. A number of viable expanded strategies are stipulated. PMID:23620458

  7. Culture and Manipulation of Embryonic Cells

    PubMed Central

    Edgar, Lois G.; Goldstein, Bob

    2012-01-01

    The direct manipulation of embryonic cells is an important tool for addressing key questions in cell and developmental biology. C. elegans is relatively unique among genetic model systems in being amenable to manipulation of embryonic cells. Embryonic cell manipulation has allowed the identification of cell interactions by direct means, and it has been an important technique for dissecting mechanisms by which cell fates are specified, cell divisions are oriented, and morphogenesis is accomplished. Here, we present detailed methods for isolating, manipulating and culturing embryonic cells of C. elegans. PMID:22226523

  8. Determining the Primary Endpoint for a Stimulant Abuse Trial: Lessons Learned from STRIDE (CTN 0037)

    PubMed Central

    Trivedi, Madhukar H.; Greer, Tracy L.; Potter, Jennifer Sharpe; Grannemann, Bruce D.; Nunes, Edward V.; Rethorst, Chad; Warden, Diane; Ring, Kolette M.; Somoza, Eugene

    2012-01-01

    Background No consensus is available for identifying the best primary outcome for substance abuse trials. While abstinence is the most desirable outcome for substance use interventions, a wide variety of other endpoints have been used to evaluate efficacy trials. Objectives This report provides a framework for determining an optimal primary endpoint and the relevant measurement approach for substance use disorder treatment trials. The framework was developed based on a trial for stimulant abuse using exercise as an augmentation treatment, delivered within the NIDA Clinical Trials Network. The use of a common primary endpoint across trials will facilitate comparisons of treatment efficacy. Methods Primary endpoint options in existing substance abuse studies were evaluated. This evaluation included surveys of the literature for endpoints and measurement approaches, followed by assessment of endpoint choices against study design issues, population characteristics, tests of sensitivity and tests of clinical meaningfulness. Conclusion We concluded that the best current choice for a primary endpoint is percent days abstinent, as measured by the Time Line Follow Back (TLFB) interview conducted three times a week with recall aided by a take-home Substance Use Diary. To further improve the accuracy of the self-reported drug use, an algorithm will be applied to reconcile the results from the TLFB with the results of qualitative urine drug screens. Scientific Significance There is a need for a standardized endpoint in this field to allow for comparison across treatment studies, and we suggest that the recommended endpoint be considered for use in this field. PMID:21854276

  9. Equilibrium-Based Movement Endpoints Elicited from Primary Motor Cortex Using Repetitive Microstimulation

    PubMed Central

    Van Acker, Gustaf M.; Amundsen, Sommer L.; Messamore, William G.; Zhang, Hongyu Y.; Luchies, Carl W.

    2014-01-01

    High-frequency, long-duration intracortical microstimulation (HFLD-ICMS) is increasingly being used to deduce how the brain encodes coordinated muscle activity and movement. However, the full movement repertoire that can be elicited from the forelimb representation of primary motor cortex (M1) using this method has not been systematically determined. Our goal was to acquire a comprehensive M1 forelimb representational map of movement endpoints elicited with HFLD-ICMS, using stimulus parameters optimal for evoking stable forelimb spatial endpoints. The data reveal a 3D forelimb movement endpoint workspace that is represented in a patchwork fashion on the 2D M1 cortical surface. Although cortical maps of movement endpoints appear quite disorderly with respect to movement space, we show that the endpoint locations in the workspace evoked with HFLD-ICMS of two adjacent cortical points are closer together than would be expected if the organization were random. Although there were few obvious consistencies in the endpoint maps across the two monkeys tested, one notable exception was endpoints bringing the hand to the mouth, which was located at the boundary between the hand and face representation. Endpoints at the extremes of the monkey's workspace and locations above the head were largely absent. Our movement endpoints are best explained as resulting from coactivation of agonist and antagonist muscles driving the joints toward equilibrium positions determined by the length–tension relationships of the muscles. PMID:25411500

  10. WATER COLUMN TOXICITY FROM CONTAMINATED MARINE SEDIMENTS: EFFECTS ON MULTIPLE ENDPOINTS OF THREE MARINE SPECIES

    EPA Science Inventory

    Water quality monitoring programs often include toxicity testing of ambient waters with the assumption that observed toxicity is due to existing anthropogenic discharges. hese assessments rarely consider the potential that water column toxicity may originate from contaminated sed...

  11. Longitudinal assessment of hemodynamic endpoints in predicting arteriovenous fistula maturation.

    PubMed

    Rajabi-Jagahrgh, Ehsan; Krishnamoorthy, Mahesh K; Roy-Chaudhury, Prabir; Succop, Paul; Wang, Yang; Choe, Ann; Banerjee, Rupak K

    2013-01-01

    Arteriovenous fistula (AVF) nonmaturation is currently a significant clinical problem; however, the mechanisms responsible for this have remained unanswered. Previous work by our group and others has suggested that anatomical configuration and the corresponding hemodynamic endpoints could have an important role in AVF remodeling. Thus, our goal was to assess the longitudinal (temporal) effect of wall shear stress (WSS) on remodeling process of AVFs with two different configurations. The hypothesis is that early assessment of hemodynamic endpoints such as temporal gradient of WSS will predict the maturation status of AVF at later time points. Two AVFs with curved (C-AVF) and straight (S-AVF) configurations were created between the femoral artery and vein of each pig. Three pigs were considered in this study and in total six AVFs (three C-AVF and three S-AVF) were created. The CT scan and ultrasound were utilized to numerically evaluate local WSS at 20 cross-sections along the venous segment of AVFs at 2D (D: days), 7D, and 28D postsurgery. These cross-sections were located at 1.5 mm increments from the anastomosis junction. Local WSS values at these cross-sections were correlated with their corresponding luminal area over time. The WSS in C-AVF decreased from 22.3 ± 4.8 dyn/cm(2) at 2D to 4.1 ± 5.1 dyn/cm(2) at 28D, while WSS increased in S-AVF from 13.0 ± 5.0 dyn/cm(2) at 2D to 36.7 ± 5.3 dyn/cm(2) at 28D. Corresponding to these changes in WSS levels, luminal area of C-AVF dilated (0.23 ± 0.14 cm(2) at 2D to 0.87 ± 0.14 cm(2) at 28D) with attendant increase in flow rate. However, S-AVF had minimal changes in area (0.26 ± 0.02 cm(2) at 2D to 0.27 ± 0.03 cm(2) at 28D) despite some increase in flow rate. Our results suggest that the temporal changes of WSS could have significant effects on AVF maturation. Reduction in WSS over time (regardless of initial values) may result in dilation (p < 0.05), while increase in WSS may be detrimental to maturation. Thus

  12. Maternal embryonic leucine zipper kinase (MELK): a novel regulator in cell cycle control, embryonic development, and cancer.

    PubMed

    Jiang, Pengfei; Zhang, Deli

    2013-01-01

    Maternal embryonic leucine zipper kinase (MELK) functions as a modulator of intracellular signaling and affects various cellular and biological processes, including cell cycle, cell proliferation, apoptosis, spliceosome assembly, gene expression, embryonic development, hematopoiesis, and oncogenesis. In these cellular processes, MELK functions by binding to numerous proteins. In general, the effects of multiple protein interactions with MELK are oncogenic in nature, and the overexpression of MELK in kinds of cancer provides some evidence that it may be involved in tumorigenic process. In this review, our current knowledge of MELK function and recent discoveries in MELK signaling pathway were discussed. The regulation of MELK in cancers and its potential as a therapeutic target were also described. PMID:24185907

  13. Use of diatom motility features as endpoints of metolachlor toxicity.

    PubMed

    Coquillé, Nathalie; Jan, Gwilherm; Moreira, Aurélie; Morin, Soizic

    2015-01-01

    Many recent ecotoxicological studies suggest a relationship between freshwater contamination and increasing abundances of motile diatoms (potentially able to move). The capacity to escape would present advantages to species in polluted environments. However, actual motility as a response to toxicants had not been described and required experimental validation. We designed a specific experiment to assess how a field-isolated diatom (Gomphonema gracile) distributes energy to in situ resistance (increased population growth or photosynthesis) and escape (behavioral changes), when exposed to increasing concentrations of the herbicide metolachlor. We report here the dose-time dependent responses of G. gracile populations. They coped with low contamination by resisting in situ, with early hormetic responses highlighted by stimulation of chlorophyll-a fluorescence. At a higher dose, harmful impacts were observed on growth after a few days, but an earlier behavioral response suggested that higher motility (percentage of motile individuals and mean distance crossed) could be involved in escape. Our findings bring new arguments to support the implementation of real measurements instead of motility traits in toxicity assessment. Specifically, motion descriptors have been used as early-warning indicators of contamination in our study. Further works should address the reliability of these endpoints in more complex conditions (interspecific variability, behavior in the field). PMID:25481786

  14. Site closure: Environmentally acceptable endpoints for petroleum hydrocarbon impacted soils

    SciTech Connect

    Huddleston, R.L.; Meyers, J.D.

    1996-12-31

    Site closure requirements for petroleum hydrocarbon impacted soils are currently based on rigorous solvent extraction of the soils. This approach to site closure ignores natural mechanisms which sequester organic materials in soils. These processes can eliminate, or greatly reduce, the mobility and availability of chemicals and thereby their risk to human health and the environment. A more appropriate way to evaluate the environmental threat of an impacted soil is to establish the {open_quotes}Environmentally Acceptable Endpoint{close_quotes} - EAE. EAE is the threshold concentration of chemicals in the soil below which there is no unacceptable risk to human health or the environment. Sequestration can strongly influence the EAE. In May, 1955 the Gas Research Institute convened an expert workshop to review EAE as related to petroleum HC. It was concluded that sequestration and EAE are scientifically sound principles, and should be considered in evaluating site closure. It was also concluded that more data are needed to clarify specific aspects of petroleum HC EAE. A comprehensive research effort has been initiated under the Petroleum Environmental Research Forum (PERF) umbrella. This effort will generate data required to allow broader acceptance and application of-this appropriate, scientifically sound, and cost effective approach for closure of petroleum HC impacted sites.

  15. Site closure: Environmentally acceptable endpoints for petroleum hydrocarbon impacted soils

    SciTech Connect

    Huddleston, R.L. ); Meyers, J.D. )

    1996-01-01

    Site closure requirements for petroleum hydrocarbon impacted soils are currently based on rigorous solvent extraction of the soils. This approach to site closure ignores natural mechanisms which sequester organic materials in soils. These processes can eliminate, or greatly reduce, the mobility and availability of chemicals and thereby their risk to human health and the environment. A more appropriate way to evaluate the environmental threat of an impacted soil is to establish the [open quotes]Environmentally Acceptable Endpoint[close quotes] - EAE. EAE is the threshold concentration of chemicals in the soil below which there is no unacceptable risk to human health or the environment. Sequestration can strongly influence the EAE. In May, 1955 the Gas Research Institute convened an expert workshop to review EAE as related to petroleum HC. It was concluded that sequestration and EAE are scientifically sound principles, and should be considered in evaluating site closure. It was also concluded that more data are needed to clarify specific aspects of petroleum HC EAE. A comprehensive research effort has been initiated under the Petroleum Environmental Research Forum (PERF) umbrella. This effort will generate data required to allow broader acceptance and application of-this appropriate, scientifically sound, and cost effective approach for closure of petroleum HC impacted sites.

  16. Virus isolation and propagation in embryonating eggs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The embryonating egg is one of the most versatile, easy to work with, and widely used host systems for the isolation and propagation of avian viruses. The embryonating chicken egg (ECE) is the most commonly available system that is both specific pathogen free and supports the replication of viruses...

  17. Use of sublethal endpoints in sediment toxicity testing with the amphipod Hyalella azteca

    SciTech Connect

    Kemble, N.E.; Brunson, E.B.; Dwyer, F.J.; Ehrhardt, E.A.; Hardesty, D.K.; Haverland, P.S.; Ingersoll, C.G.

    1995-12-31

    ASTM and EPA standard methods for sediment toxicity tests with Hyalella azteca typically recommend use of lethality as the endpoint in a 10-d exposure. However, data from 10- to 28-d exposures with amphipods indicate sublethal endpoints (i.e., growth, sexual maturation, or reproduction) identify additional samples as toxic. The authors compared the frequency that lethal and sublethal endpoints identified a sediment sample as toxic in 14- and 28-d amphipod exposures. In the 14-d amphipod exposures, lethality identified 20% of the samples as toxic, and sublethal endpoints identified an additional 16% of the samples as toxic using sublethal endpoints only. Similarly, in the 28-d exposures, lethality identified 14% of the samples as toxic and sublethal endpoints identified an additional 18% of the samples as toxic. The authors are also currently evaluating Sediment Effect Concentrations (SECs) relative to both lethal and sublethal endpoints in H. azteca exposures. These SECs will be used to evaluate reliability in estimating toxicity of samples. Potential factors which may confound interpretation of sublethal endpoints in sediment tests include: (1) changes in sediment chemistry resulting from long-term storage or feeding (2) the influence of physical characteristics of sediment (grain size), and (3) effects of ammonia or hydrogen sulfide.

  18. Statistical evaluation of surrogate endpoints with examples from cancer clinical trials.

    PubMed

    Buyse, Marc; Molenberghs, Geert; Paoletti, Xavier; Oba, Koji; Alonso, Ariel; Van der Elst, Wim; Burzykowski, Tomasz

    2016-01-01

    A surrogate endpoint is intended to replace a clinical endpoint for the evaluation of new treatments when it can be measured more cheaply, more conveniently, more frequently, or earlier than that clinical endpoint. A surrogate endpoint is expected to predict clinical benefit, harm, or lack of these. Besides the biological plausibility of a surrogate, a quantitative assessment of the strength of evidence for surrogacy requires the demonstration of the prognostic value of the surrogate for the clinical outcome, and evidence that treatment effects on the surrogate reliably predict treatment effects on the clinical outcome. We focus on these two conditions, and outline the statistical approaches that have been proposed to assess the extent to which these conditions are fulfilled. When data are available from a single trial, one can assess the "individual level association" between the surrogate and the true endpoint. When data are available from several trials, one can additionally assess the "trial level association" between the treatment effect on the surrogate and the treatment effect on the true endpoint. In the latter case, the "surrogate threshold effect" can be estimated as the minimum effect on the surrogate endpoint that predicts a statistically significant effect on the clinical endpoint. All these concepts are discussed in the context of randomized clinical trials in oncology, and illustrated with two meta-analyses in gastric cancer. PMID:25682941

  19. Combining progression-free survival and overall survival as a novel composite endpoint for glioblastoma trials

    PubMed Central

    Trippa, Lorenzo; Wen, Patrick Y.; Parmigiani, Giovanni; Berry, Donald A.; Alexander, Brian M.

    2015-01-01

    Background The use of auxiliary endpoints may provide efficiencies for clinical trial design, but such endpoints may not have intrinsic clinical relevance or clear linkage to more meaningful endpoints. The purpose of this study was to generate a novel endpoint that considers both overall survival (OS) and earlier events such as progression-free survival (PFS) and determine whether such an endpoint could increase efficiency in the design of glioblastoma clinical trials. Methods Recognizing that the association between PFS and OS varies depending on therapy and tumor type, we developed a statistical model to predict OS based on PFS as the trial progresses. We then evaluated the efficiency of our model using simulations of adaptively randomized trials incorporating PFS and OS distributions from prior published trials in neuro-oncology. Results When treatment effects on PFS and OS are concordant, our proposed approach results in efficiency gains compared with randomization based on OS alone while sacrificing minimal efficiency compared with using PFS as the primary endpoint. When treatment effects are limited to PFS, our approach provides randomization probabilities that are close to those based on OS alone. Conclusion Use of OS as the primary endpoint, combined with statistical modeling of the relationship between OS and PFS during the course of the trial, results in more robust and efficient trial designs than using either endpoint alone. PMID:25568226

  20. Attention to Endpoints: A Cross-Linguistic Constraint on Spatial Meaning

    ERIC Educational Resources Information Center

    Regier, Terry; Zheng, Mingyu

    2007-01-01

    We investigate a possible universal constraint on spatial meaning. It has been proposed that people attend preferentially to the endpoints of spatial motion events, and that languages may therefore make finer semantic distinctions at event endpoints than at event beginnings. We test this proposal. In Experiment 1, we show that people discriminate…

  1. Observations on Three Endpoint Properties and Their Relationship to Regulatory Outcomes of European Oncology Marketing Applications

    PubMed Central

    Stolk, Pieter; McAuslane, James Neil; Schellens, Jan; Breckenridge, Alasdair M.; Leufkens, Hubert

    2015-01-01

    Background. Guidance and exploratory evidence indicate that the type of endpoints and the magnitude of their outcome can define a therapy’s clinical activity; however, little empirical evidence relates specific endpoint properties with regulatory outcomes. Materials and Methods. We explored the relationship of 3 endpoint properties to regulatory outcomes by assessing 50 oncology marketing authorization applications (MAAs; reviewed from 2009 to 2013). Results. Overall, 16 (32%) had a negative outcome. The most commonly used hard endpoints were overall survival (OS) and the duration of response or stable disease. OS was a component of 91% approved and 63% failed MAAs. The most commonly used surrogate endpoints were progression-free survival (PFS), response rate, and health-related quality of life assessments. There was no difference (p = .3801) between the approved and failed MAA cohorts in the proportion of hard endpoints used. A mean of slightly more than four surrogate endpoints were used per approved MAA compared with slightly more than two for failed MAAs. Longer OS and PFS duration outcomes were generally associated with approvals, often when not statistically significant. The approved cohort was associated with a preponderance of statistically significant (p < .05) improvements in primary endpoints (p < .0001 difference between the approved and failed groups). Conclusion. Three key endpoint properties (type of endpoint [hard/surrogate], magnitude of an endpoint outcome, and its statistical significance) are consistent with the European Medicines Agency guidance and, notwithstanding the contribution of unique disease-specific circumstances, are associated with a predictable positive outcome for oncology MAAs. Implications for Practice: Regulatory decisions made by the European Medicines Agency determine which new medicines will be available to European prescribers and for which therapeutic indications. Regulatory success or failure can be influenced by many

  2. STATISTICAL METHODOLOGY FOR THE SIMULTANEOUS ANALYSIS OF MULTIPLE TYPES OF OUTCOMES IN NONLINEAR THRESHOLD MODELS.

    EPA Science Inventory

    Multiple outcomes are often measured on each experimental unit in toxicology experiments. These multiple observations typically imply the existence of correlation between endpoints, and a statistical analysis that incorporates it may result in improved inference. When both disc...

  3. Avian embryonic development in hyperdynamic environments

    NASA Technical Reports Server (NTRS)

    Abbott, U. K.; Smith, A. H.

    1983-01-01

    Embryos which developed for 24 hours in the oviduct of hens maintained at 2 G and which were subsequently incubated at Earth gravity had a 14% reduction in hatchability. Increased mortality during the first 4 days, and an increase in embryonic abnormalities were of the types usually found during the first mortality peak (2-3 days). Embryos in eggs that were produced at Earth gravity and continued their development on the centrifuge at fields of 2 G or less did not appear to be greatly affected by the treatment. At 4 G, 91% of the embryos died, mostly on the first and second days of incubation. Abnormalities prominent in the centrifuged eggs include: (a) a failure of the primitive streak to develop; (b) interference with the development of the axial skeleton; (c) multiple hemorrhages, mostly petechial which is consistent with capillary fragility; and (d) retardation of embryo growth, possibly caused by an interference with gaseous diffusion, the result of an acceleration-induced increase in gas density in the centrifuging incubator.

  4. In vitro pancreas organogenesis from dispersed mouse embryonic progenitors.

    PubMed

    Greggio, Chiara; De Franceschi, Filippo; Figueiredo-Larsen, Manuel; Grapin-Botton, Anne

    2014-01-01

    The pancreas is an essential organ that regulates glucose homeostasis and secretes digestive enzymes. Research on pancreas embryogenesis has led to the development of protocols to produce pancreatic cells from stem cells (1). The whole embryonic organ can be cultured at multiple stages of development (2-4). These culture methods have been useful to test drugs and to image developmental processes. However the expansion of the organ is very limited and morphogenesis is not faithfully recapitulated since the organ flattens. We propose three-dimensional (3D) culture conditions that enable the efficient expansion of dissociated mouse embryonic pancreatic progenitors. By manipulating the composition of the culture medium it is possible to generate either hollow spheres, mainly composed of pancreatic progenitors expanding in their initial state, or, complex organoids which progress to more mature expanding progenitors and differentiate into endocrine, acinar and ductal cells and which spontaneously self-organize to resemble the embryonic pancreas. We show here that the in vitro process recapitulates many aspects of natural pancreas development. This culture system is suitable to investigate how cells cooperate to form an organ by reducing its initial complexity to few progenitors. It is a model that reproduces the 3D architecture of the pancreas and that is therefore useful to study morphogenesis, including polarization of epithelial structures and branching. It is also appropriate to assess the response to mechanical cues of the niche such as stiffness and the effects on cell´s tensegrity. PMID:25079453

  5. In Vitro Pancreas Organogenesis from Dispersed Mouse Embryonic Progenitors

    PubMed Central

    Grapin-Botton, Anne

    2014-01-01

    The pancreas is an essential organ that regulates glucose homeostasis and secretes digestive enzymes. Research on pancreas embryogenesis has led to the development of protocols to produce pancreatic cells from stem cells 1. The whole embryonic organ can be cultured at multiple stages of development 2-4. These culture methods have been useful to test drugs and to image developmental processes. However the expansion of the organ is very limited and morphogenesis is not faithfully recapitulated since the organ flattens. We propose three-dimensional (3D) culture conditions that enable the efficient expansion of dissociated mouse embryonic pancreatic progenitors. By manipulating the composition of the culture medium it is possible to generate either hollow spheres, mainly composed of pancreatic progenitors expanding in their initial state, or, complex organoids which progress to more mature expanding progenitors and differentiate into endocrine, acinar and ductal cells and which spontaneously self-organize to resemble the embryonic pancreas. We show here that the in vitro process recapitulates many aspects of natural pancreas development. This culture system is suitable to investigate how cells cooperate to form an organ by reducing its initial complexity to few progenitors. It is a model that reproduces the 3D architecture of the pancreas and that is therefore useful to study morphogenesis, including polarization of epithelial structures and branching. It is also appropriate to assess the response to mechanical cues of the niche such as stiffness and the effects on cell´s tensegrity. PMID:25079453

  6. Embryonic blood-cerebrospinal fluid barrier formation and function

    PubMed Central

    Bueno, David; Parvas, Maryam; Hermelo, Ismaïl; Garcia-Fernàndez, Jordi

    2014-01-01

    During embryonic development and adult life, brain cavities and ventricles are filled with cerebrospinal fluid (CSF). CSF has attracted interest as an active signaling medium that regulates brain development, homeostasis and disease. CSF is a complex protein-rich fluid containing growth factors and signaling molecules that regulate multiple cell functions in the central nervous system (CNS). The composition and substance concentrations of CSF are tightly controlled. In recent years, it has been demonstrated that embryonic CSF (eCSF) has a key function as a fluid pathway for delivering diffusible signals to the developing brain, thus contributing to the proliferation, differentiation and survival of neural progenitor cells, and to the expansion and patterning of the brain. From fetal stages through to adult life, CSF is primarily produced by the choroid plexus. The development and functional activities of the choroid plexus and other blood–brain barrier (BBB) systems in adults and fetuses have been extensively analyzed. However, eCSF production and control of its homeostasis in embryos, from the closure of the anterior neuropore when the brain cavities become physiologically sealed, to the formation of the functional fetal choroid plexus, has not been studied in as much depth and remains open to debate. This review brings together the existing literature, some of which is based on experiments conducted by our research group, concerning the formation and function of a temporary embryonic blood–CSF barrier in the context of the crucial roles played by the molecules in eCSF. PMID:25389383

  7. Endpoints and cutpoints in head and neck oncology trials: methodical background, challenges, current practice and perspectives.

    PubMed

    Hezel, Marcus; von Usslar, Kathrin; Kurzweg, Thiemo; Lörincz, Balazs B; Knecht, Rainald

    2016-04-01

    This article reviews the methodical and statistical basics of designing a trial, with a special focus on the process of defining and choosing endpoints and cutpoints as the foundations of clinical research, and ultimately that of evidence-based medicine. There has been a significant progress in the treatment of head and neck cancer in the past few decades. Currently available treatment options can have a variety of different goals, depending e.g. on tumor stage, among other factors. The outcome of a specific treatment in clinical trials is measured using endpoints. Besides classical endpoints, such as overall survival or organ preservation, other endpoints like quality of life are becoming increasingly important in designing and conducting a trial. The present work is based on electronic research and focuses on the solid methodical and statistical basics of a clinical trial, on the structure of study designs and on the presentation of various endpoints. PMID:25573834

  8. Genotoxic and teratogenic effect of freshwater sediment samples from the Rhine and Elbe River (Germany) in zebrafish embryo using a multi-endpoint testing strategy.

    PubMed

    Garcia-Käufer, M; Gartiser, S; Hafner, C; Schiwy, S; Keiter, S; Gründemann, C; Hollert, H

    2015-11-01

    The embryotoxic potential of three model sediment samples with a distinct and well-characterized pollutant burden from the main German river basins Rhine and Elbe was investigated. The Fish Embryo Contact Test (FECT) in zebrafish (Danio rerio) was applied and submitted to further development to allow for a comprehensive risk assessment of such complex environmental samples. As particulate pollutants are constructive constituents of sediments, they underlay episodic source-sink dynamics, becoming available to benthic organisms. As bioavailability of xenobiotics is a crucial factor for ecotoxicological hazard, we focused on the direct particle-exposure pathway, evaluating throughput-capable endpoints and considering toxicokinetics. Fish embryo and larvae were exposed toward reconstituted (freeze-dried) sediment samples on a microcosm-scale experimental approach. A range of different developmental embryonic stages were considered to gain knowledge of potential correlations with metabolic competence during the early embryogenesis. Morphological, physiological, and molecular endpoints were investigated to elucidate induced adverse effects, placing particular emphasis on genomic instability, assessed by the in vivo comet assay. Flow cytometry was used to investigate the extent of induced cell death, since cytotoxicity can lead to confounding effects. The implementation of relative toxicity indices further provides inter-comparability between samples and related studies. All of the investigated sediments represent a significant ecotoxicological hazard by disrupting embryogenesis in zebrafish. Beside the induction of acute toxicity, morphological and physiological embryotoxic effects could be identified in a concentration-response manner. Increased DNA strand break frequency was detected after sediment contact in characteristic non-monotonic dose-response behavior due to overlapping cytotoxic effects. The embryonic zebrafish toxicity model along with the in vivo comet

  9. Biomarkers of intermediate endpoints in environmental and occupational health.

    PubMed

    Knudsen, Lisbeth E; Hansen, Ase M

    2007-05-01

    The use of biomarkers in environmental and occupational health is increasing due to increasing demands on information about health risks from unfavourable exposures. Biomarkers provide information about individual loads. Biomarkers of intermediate endpoints benefit in comparison with biomarkers of exposure from the fact that they are closer to the adverse outcome in the pathway from exposure to health effects and may provide powerful information for intervention. Some biomarkers are specific, e.g., DNA and protein adducts, while others are unspecific like the cytogenetic biomarkers of chromosomal aberrations (CA), sister chromatid exchanges and micronuclei (MN). The validation of biomarkers includes measurements of sensitivity and specificity of biomarkers and round robin tests to ensure reproducible protocols within different laboratories. The predictive value of biomarkers with respect to adverse health effect from the result of the measurement has been performed for the cytogenetic biomarkers showing a predictive value of high levels of CA and increased risk of cancer. The use of CA in future studies is, however, limited by the laborious and sensitive procedure of the test and lack of trained cytogeneticists. Less time consuming, but robust biomarkers, sensitive to environmental exposures are suggested. From the selection of developed biomarkers, the comet assay is highly sensitive to lifestyle exposures, often confounding the output, while MN in lymphocytes seem promising with respect to laboratory and health effect (cancer) validity. Also, new biomarkers exploiting the new 'omics' technologies are being developed. A number of ethical issues arise from the use of biomarkers with a predictive value aiming at respecting the autonomy of the study person in participation (only upon written informed consent and with obligations of withdrawal at any time), access to personal information (right to know and right not to know the study result) and securing proper data

  10. A Few Endpoint Geodesic Restriction Estimates for Eigenfunctions

    NASA Astrophysics Data System (ADS)

    Chen, Xuehua; Sogge, Christopher D.

    2014-07-01

    We prove a couple of new endpoint geodesic restriction estimates for eigenfunctions. In the case of general 3-dimensional compact manifolds, after a TT* argument, simply by using the L 2-boundedness of the Hilbert transform on , we are able to improve the corresponding L 2-restriction bounds of Burq, Gérard and Tzvetkov (Duke Math J 138:445-486, 2007) and Hu (Forum Math 6:1021-1052, 2009). Also, in the case of 2-dimensional compact manifolds with nonpositive curvature, we obtain improved L 4-estimates for restrictions to geodesics, which, by Hölder's inequality and interpolation, implies improved L p -bounds for all exponents p ≥ 2. We do this by using oscillatory integral theorems of Hörmander (Ark Mat 11:1-11, 1973), Greenleaf and Seeger (J Reine Angew Math 455:35-56, 1994) and Phong and Stein (Int Math Res Notices 4:49-60, 1991), along with a simple geometric lemma (Lemma 3.2) about properties of the mixed-Hessian of the Riemannian distance function restricted to pairs of geodesics in Riemannian surfaces. We are also able to get further improvements beyond our new results in three dimensions under the assumption of constant nonpositive curvature by exploiting the fact that, in this case, there are many totally geodesic submanifolds.

  11. Developmental angiogenesis: quail embryonic vasculature.

    PubMed

    Poole, T J; Coffin, J D

    1988-03-01

    We have examined the segregation and early morphogenesis of the embryonic vasculature by using a monoclonal antibody for immunofluorescence and by scanning electron microscopy. This antibody labels the presumptive endothelial cells (PECs) as they segregate from mesoderm. Similar embryos prepared for SEM revealed finer details of how these segregated cells interact to form the rudiments of the major blood vessels. Here we concentrate on the development of the dorsal aortae and the posterior cardinal veins. The dorsal aortae form from single PECs which segregate from the lateral mesoderm and aggregate into a loose cord ventral to the somites. These cells become more closely associated and a lumen forms. The posterior cardinal veins form from a loose plexus of cells segregated from the lateral mesoderm on its dorsal surface. These cells become intimately associated with the Wolffian ducts. PMID:3285464

  12. Undifferentiated Embryonal Sarcoma of Liver

    PubMed Central

    Kallam, Avyakta; Krishnamurthy, Jairam; Kozel, Jessica

    2015-01-01

    Undifferentiated embryonal sarcoma of the liver (UESL) is a rare malignant hepatic tumor. A 47 year old male presented with symptoms of sour taste in his mouth, occasional nausea, indigestion and 15-pound weight loss over two months. He had an unremarkable upper gastrointestinal endoscopy. Imaging showed a large liver mass in the left hepatic lobe that was resected and then reported as UESL. He went on to develop lung metastases and was initially treated with doxorubicin and ifosfamide followed by switching of therapy to gemcitabine and docetaxel due to progression of disease. He had a good response after two cycles and went on to receive four more cycles, achieving stable disease. We can therefore conclude that the combination of gemcitabine and docetaxel is a potential therapeutic option for patients with UESL. PMID:26788276

  13. Infrared inhibition of embryonic hearts

    NASA Astrophysics Data System (ADS)

    Wang, Yves T.; Rollins, Andrew M.; Jenkins, Michael W.

    2016-06-01

    Infrared control is a new technique that uses pulsed infrared lasers to thermally alter electrical activity. Originally developed for nerves, we have applied this technology to embryonic hearts using a quail model, previously demonstrating infrared stimulation and, here, infrared inhibition. Infrared inhibition enables repeatable and reversible block, stopping cardiac contractions for several seconds. Normal beating resumes after the laser is turned off. The block can be spatially specific, affecting propagation on the ventricle or initiation on the atrium. Optical mapping showed that the block affects action potentials and not just calcium or contraction. Increased resting intracellular calcium was observed after a 30-s exposure to the inhibition laser, which likely resulted in reduced mechanical function. Further optimization of the laser illumination should reduce potential damage. Stopping cardiac contractions by disrupting electrical activity with infrared inhibition has the potential to be a powerful tool for studying the developing heart.

  14. Undifferentiated Embryonal Sarcoma of Liver.

    PubMed

    Kallam, Avyakta; Krishnamurthy, Jairam; Kozel, Jessica; Shonka, Nicole

    2015-12-29

    Undifferentiated embryonal sarcoma of the liver (UESL) is a rare malignant hepatic tumor. A 47 year old male presented with symptoms of sour taste in his mouth, occasional nausea, indigestion and 15-pound weight loss over two months. He had an unremarkable upper gastrointestinal endoscopy. Imaging showed a large liver mass in the left hepatic lobe that was resected and then reported as UESL. He went on to develop lung metastases and was initially treated with doxorubicin and ifosfamide followed by switching of therapy to gemcitabine and docetaxel due to progression of disease. He had a good response after two cycles and went on to receive four more cycles, achieving stable disease. We can therefore conclude that the combination of gemcitabine and docetaxel is a potential therapeutic option for patients with UESL. PMID:26788276

  15. Center-Within-Trial Versus Trial-Level Evaluation of Surrogate Endpoints

    PubMed Central

    Renfro, Lindsay A.; Shi, Qian; Xue, Yuan; Li, Junlong; Shang, Hongwei; Sargent, Daniel J.

    2014-01-01

    Evaluation of candidate surrogate endpoints using individual patient data from multiple clinical trials is considered the gold standard approach to validate surrogates at both patient and trial levels. However, this approach assumes the availability of patient-level data from a relatively large collection of similar trials, which may not be possible to achieve for a given disease application. One common solution to the problem of too few similar trials involves performing trial-level surrogacy analyses on trial sub-units (e.g., centers within trials), thereby artificially increasing the trial-level sample size for feasibility of the multi-trial analysis. To date, the practical impact of treating trial sub-units (centers) identically to trials in multi-trial surrogacy analyses remains unexplored, and conditions under which this ad hoc solution may in fact be reasonable have not been identified. We perform a simulation study to identify such conditions, and demonstrate practical implications using a multi-trial dataset of patients with early stage colon cancer. PMID:25061255

  16. Design and analysis of three-arm trials with negative binomially distributed endpoints.

    PubMed

    Mütze, Tobias; Munk, Axel; Friede, Tim

    2016-02-20

    A three-arm clinical trial design with an experimental treatment, an active control, and a placebo control, commonly referred to as the gold standard design, enables testing of non-inferiority or superiority of the experimental treatment compared with the active control. In this paper, we propose methods for designing and analyzing three-arm trials with negative binomially distributed endpoints. In particular, we develop a Wald-type test with a restricted maximum-likelihood variance estimator for testing non-inferiority or superiority. For this test, sample size and power formulas as well as optimal sample size allocations will be derived. The performance of the proposed test will be assessed in an extensive simulation study with regard to type I error rate, power, sample size, and sample size allocation. For the purpose of comparison, Wald-type statistics with a sample variance estimator and an unrestricted maximum-likelihood estimator are included in the simulation study. We found that the proposed Wald-type test with a restricted variance estimator performed well across the considered scenarios and is therefore recommended for application in clinical trials. The methods proposed are motivated and illustrated by a recent clinical trial in multiple sclerosis. The R package ThreeArmedTrials, which implements the methods discussed in this paper, is available on CRAN. PMID:26388314

  17. 28. Embryonic and adult stem cell therapy.

    PubMed

    Henningson, Carl T; Stanislaus, Marisha A; Gewirtz, Alan M

    2003-02-01

    Stem cells are characterized by the ability to remain undifferentiated and to self-renew. Embryonic stem cells derived from blastocysts are pluripotent (able to differentiate into many cell types). Adult stem cells, which were traditionally thought to be monopotent multipotent, or tissue restricted, have recently also been shown to have pluripotent properties. Adult bone marrow stem cells have been shown to be capable of differentiating into skeletal muscle, brain microglia and astroglia, and hepatocytes. Stem cell lines derived from both embryonic stem and embryonic germ cells (from the embryonic gonadal ridge) are pluripotent and capable of self-renewal for long periods. Therefore embryonic stem and germ cells have been widely investigated for their potential to cure diseases by repairing or replacing damaged cells and tissues. Studies in animal models have shown that transplantation of fetal, embryonic stem, or embryonic germ cells may be able to treat some chronic diseases. In this review, we highlight recent developments in the use of stem cells as therapeutic agents for three such diseases: Diabetes, Parkinson disease, and congestive heart failure. We also discuss the potential use of stem cells as gene therapy delivery cells and the scientific and ethical issues that arise with the use of human stem cells. PMID:12592319

  18. Endpoints of Resuscitation of Critically Injured Patients: Normal or Supranormal?

    PubMed Central

    Velmahos, George C.; Demetriades, Demetrios; Shoemaker, William C.; Chan, Linda S.; Tatevossian, Raymond; Wo, Charles C. J.; Vassiliu, Pantelis; Cornwell, Edward E.; Murray, James A.; Roth, Bradley; Belzberg, Howard; Asensio, Juan A.; Berne, Thomas V.

    2000-01-01

    Objective To evaluate the effect of early optimization in the survival of severely injured patients. Summary Background Data It is unclear whether supranormal (“optimal”) hemodynamic values should serve as endpoints of resuscitation or simply as markers of the physiologic reserve of critically injured patients. The failure of optimization to produce improved survival in some randomized controlled trials may be associated with delays in starting the attempt to reach optimal goals. There are limited controlled data on trauma patients. Methods Seventy-five consecutive severely injured patients with shock resulting from bleeding and without major intracranial or spinal cord trauma were randomized to resuscitation, starting immediately after admission, to either normal values of systolic blood pressure, urine output, base deficit, hemoglobin, and cardiac index (control group, 35 patients) or optimal values (cardiac index >4.5 L/min/m2, ratio of transcutaneous oxygen tension to fractional inspired oxygen >200, oxygen delivery index >600 mL/min/m2, and oxygen consumption index >170 mL/min/m2; optimal group, 40 patients). Initial cardiac output monitoring was done noninvasively by bioimpedance and, subsequently, invasively by thermodilution. Crystalloids, colloids, blood, inotropes, and vasopressors were used by predetermined algorithms. Results Optimal values were reached intentionally by 70% of the optimal patients and spontaneously by 40% of the control patients. There was no difference in rates of death (15% optimal vs. 11% control), organ failure, sepsis, or the length of intensive care unit or hospital stay between the two groups. Patients from both groups who achieved optimal values had better outcomes than patients who did not. The death rate was 0% among patients who achieved optimal values compared with 30% among patients who did not. Age younger than 40 years was the only independent predictive factor of the ability to reach optimal values. Conclusions

  19. Primary Endpoints of the Biventricular Pacing after Cardiac Surgery Trial

    PubMed Central

    Spotnitz, Henry M.; Cabreriza, Santos; Wang, Daniel Y.; Quinn, T. Alexander; Cheng, Bin; Bedrosian, Lauren; Aponte-Patel, Linda; Smith, Craig R.

    2013-01-01

    Background To determine whether optimized biventricular pacing increases cardiac index in patients at risk of left ventricular dysfunction after cardiopulmonary bypass. Procedures included coronary artery bypass, aortic or mitral surgery and combinations. This trial was approved by the Columbia University Institutional Review Board and was conducted under an Investigational Device Exemption. Methods Screening of 6,346 patients yielded 47 endpoints. With informed consent, 61 patients were randomized to pacing or control groups. Atrioventricular and interventricular delays were optimized one (Phase I), two (Phase II), and 12–24 hours (Phase III) after bypass in all patients. Cardiac index was measured by thermal dilution in triplicate. Two-sample t-test assessed differences between groups and subgroups. Results Cardiac index was 12% higher (2.83±0.16 (S.E.M.) vs. 2.52±0.13 liters/minute/square meter) in the paced group, less than predicted and not statistically significant (p=0.14). However, when aortic and aortic/mitral surgery groups were combined, cardiac index increased 29% in the paced group (2.90±0.19, n=14) vs. controls (2.24±0.15, n=11) (p=0.0138). Using a linear mixed effects model, t-test revealed that mean arterial pressure increased with pacing vs. no pacing at all optimization points (Phase I 79.2±1.7 vs. 74.5±1.6 mmHg, p=0.008, Phase II 75.9±1.5 vs. 73.6±1.8, p=0.006, Phase III 81.9±2.8 vs. 79.5±2.7, p=0.002) Conclusions Cardiac index did not increase significantly overall but increased 29% after aortic valve surgery. Mean arterial pressure increased with pacing at three time points. Additional studies are needed to distinguish rate from resynchronization effects, emphasize atrioventricular delay optimization, and examine clinical benefits of temporary postoperative pacing. PMID:23866800

  20. Generation of the Dimensional Embryology Application (App) for Visualization of Early Chick and Frog Embryonic Development

    ERIC Educational Resources Information Center

    Webb, Rebecca L.; Bilitski, James; Zerbee, Alyssa; Symans, Alexandra; Chop, Alexandra; Seitz, Brianne; Tran, Cindy

    2015-01-01

    The study of embryonic development of multiple organisms, including model organisms such as frogs and chicks, is included in many undergraduate biology programs, as well as in a variety of graduate programs. As our knowledge of biological systems increases and the amount of material to be taught expands, the time spent instructing students about…

  1. Role of microglia in embryonic neurogenesis

    PubMed Central

    Tong, Chih Kong

    2016-01-01

    Microglia begin colonizing the developing brain as early as embryonic day 9, prior to the emergence of neurons and other glia. Their ontogeny is also distinct from other central nervous system cells, as they derive from yolk sac hematopoietic progenitors and not neural progenitors. In this review, we feature these unique characteristics of microglia and assess the spatiotemporal similarities between microglia colonization of the central nervous system and embryonic neurogenesis. We also infer to existing evidence for microglia function from embryonic through to postnatal neurodevelopment to postulate roles for microglia in neurogenesis. PMID:27555616

  2. Role of microglia in embryonic neurogenesis.

    PubMed

    Tong, Chih Kong; Vidyadaran, Sharmili

    2016-09-01

    Microglia begin colonizing the developing brain as early as embryonic day 9, prior to the emergence of neurons and other glia. Their ontogeny is also distinct from other central nervous system cells, as they derive from yolk sac hematopoietic progenitors and not neural progenitors. In this review, we feature these unique characteristics of microglia and assess the spatiotemporal similarities between microglia colonization of the central nervous system and embryonic neurogenesis. We also infer to existing evidence for microglia function from embryonic through to postnatal neurodevelopment to postulate roles for microglia in neurogenesis. PMID:27555616

  3. Measuring time during early embryonic development.

    PubMed

    Ferree, Patrick L; Deneke, Victoria E; Di Talia, Stefano

    2016-07-01

    In most metazoans, embryonic development is orchestrated by a precise series of cellular behaviors. Understanding how such events are regulated to achieve a stereotypical temporal progression is a fundamental problem in developmental biology. In this review, we argue that studying the regulation of the cell cycle in early embryonic development will reveal novel principles of how embryos accurately measure time. We will discuss the strategies that have emerged from studying early development of Drosophila embryos. By comparing the development of flies to that of other metazoans, we will highlight both conserved and alternative mechanisms to generate precision during embryonic development. PMID:26994526

  4. Reliability of a Manual Procedure for Marking the EZ Endpoint Location in Patients with Retinitis Pigmentosa

    PubMed Central

    Ramachandran, Rithambara; X. Cai, Cindy; Lee, Dongwon; C. Epstein, Benjamin; Locke, Kirsten G.; G. Birch, David; C. Hood, Donald

    2016-01-01

    Purpose We developed and evaluated a training procedure for marking the endpoints of the ellipsoid zone (EZ), also known as the inner segment/outer segment (IS/OS) border, on frequency domain optical coherence tomography (fdOCT) scans from patients with retinitis pigmentosa (RP). Methods A manual for marking EZ endpoints was developed and used to train 2 inexperienced graders. After training, an experienced grader and the 2 trained graders marked the endpoints on fdOCT horizontal line scans through the macula from 45 patients with RP. They marked the endpoints on these same scans again 1 month later. Results Intragrader agreement was excellent. The intraclass correlation coefficient (ICC) was 0.99, the average difference of endpoint locations (19.6 μm) was close to 0 μm, and the 95% limits were between −284 and 323 μm, approximately ±1.1°. Intergrader agreement also was excellent. The ICC values were 0.98 (time 1) and 0.97 (time 2), the average difference among graders was close to zero, and the 95% limits of these differences was less than 350 μm, approximately 1.2°, for both test times. Conclusions While automated algorithms are becoming increasingly accurate, EZ endpoints still have to be verified manually and corrected when necessary. With training, the inter- and intragrader agreement of manually marked endpoints is excellent. Translational Relevance For clinical studies, the EZ endpoints can be marked by hand if a training procedure, including a manual, is used. The endpoint confidence intervals, well under ±2.0°, are considerably smaller than the 6° spacing for the typically used static visual field. PMID:27226930

  5. Relevance weighting of tier 1 endocrine screening endpoints by rank order.

    PubMed

    Borgert, Christopher J; Stuchal, Leah D; Mihaich, Ellen M; Becker, Richard A; Bentley, Karin S; Brausch, John M; Coady, Katie; Geter, David R; Gordon, Elliot; Guiney, Patrick D; Hess, Frederick; Holmes, Catherine M; LeBaron, Matthew J; Levine, Steve; Marty, Sue; Mukhi, Sandeep; Neal, Barbara H; Ortego, Lisa S; Saltmiras, David A; Snajdr, Suzanne; Staveley, Jane; Tobia, Abraham

    2014-02-01

    Weight of evidence (WoE) approaches are recommended for interpreting various toxicological data, but few systematic and transparent procedures exist. A hypothesis-based WoE framework was recently published focusing on the U.S. EPA's Tier 1 Endocrine Screening Battery (ESB) as an example. The framework recommends weighting each experimental endpoint according to its relevance for deciding eight hypotheses addressed by the ESB. Here we present detailed rationale for weighting the ESB endpoints according to three rank ordered categories and an interpretive process for using the rankings to reach WoE determinations. Rank 1 was assigned to in vivo endpoints that characterize the fundamental physiological actions for androgen, estrogen, and thyroid activities. Rank 1 endpoints are specific and sensitive for the hypothesis, interpretable without ancillary data, and rarely confounded by artifacts or nonspecific activity. Rank 2 endpoints are specific and interpretable for the hypothesis but less informative than Rank 1, often due to oversensitivity, inclusion of narrowly context-dependent components of the hormonal system (e.g., in vitro endpoints), or confounding by nonspecific activity. Rank 3 endpoints are relevant for the hypothesis but only corroborative of Ranks 1 and 2 endpoints. Rank 3 includes many apical in vivo endpoints that can be affected by systemic toxicity and nonhormonal activity. Although these relevance weight rankings (WREL ) necessarily involve professional judgment, their a priori derivation enhances transparency and renders WoE determinations amenable to methodological scrutiny according to basic scientific premises, characteristics that cannot be assured by processes in which the rationale for decisions is provided post hoc. PMID:24510745

  6. A risk-based probabilistic framework to estimate the endpoint of remediation: Concentration rebound by rate-limited mass transfer

    NASA Astrophysics Data System (ADS)

    Barros, F. P. J.; Fernã Ndez-Garcia, D.; Bolster, D.; Sanchez-Vila, X.

    2013-04-01

    Aquifer remediation is a challenging problem with environmental, social, and economic implications. As a general rule, pumping proceeds until the concentration of the target substance within the pumped water lies below a prespecified value. In this paper we estimate the a priori potential failure of the endpoint of remediation due to a rebound of concentrations driven by back diffusion. In many cases, it has been observed that once pumping ceases, a rebound in the concentration at the well takes place. For this reason, administrative approaches are rather conservative, and pumping is forced to last much longer than initially expected. While a number of physical and chemical processes might account for the presence of rebounding, we focus here on diffusion from low water mobility into high mobility zones. In this work we look specifically at the concentration rebound when pumping is discontinued while accounting for multiple mass transfer processes occurring at different time scales and parametric uncertainty. We aim to develop a risk-based optimal operation methodology that is capable of estimating the endpoint of remediation based on aquifer parameters characterizing the heterogeneous medium as well as pumping rate and initial size of the polluted area.

  7. Direct measurement of local material properties within living embryonic tissues

    NASA Astrophysics Data System (ADS)

    Serwane, Friedhelm; Mongera, Alessandro; Rowghanian, Payam; Kealhofer, David; Lucio, Adam; Hockenbery, Zachary; Campàs, Otger

    The shaping of biological matter requires the control of its mechanical properties across multiple scales, ranging from single molecules to cells and tissues. Despite their relevance, measurements of the mechanical properties of sub-cellular, cellular and supra-cellular structures within living embryos pose severe challenges to existing techniques. We have developed a technique that uses magnetic droplets to measure the mechanical properties of complex fluids, including in situ and in vivo measurements within living embryos ,across multiple length and time scales. By actuating the droplets with magnetic fields and recording their deformation we probe the local mechanical properties, at any length scale we choose by varying the droplets' diameter. We use the technique to determine the subcellular mechanics of individual blastomeres of zebrafish embryos, and bridge the gap to the tissue scale by measuring the local viscosity and elasticity of zebrafish embryonic tissues. Using this technique, we show that embryonic zebrafish tissues are viscoelastic with a fluid-like behavior at long time scales. This technique will enable mechanobiology and mechano-transduction studies in vivo, including the study of diseases correlated with tissue stiffness, such as cancer.

  8. PREDICTING TOXICOLOGICAL ENDPOINTS OF CHEMICALS USING QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIPS (QSARS)

    EPA Science Inventory

    Quantitative structure-activity relationships (QSARs) are being developed to predict the toxicological endpoints for untested chemicals similar in structure to chemicals that have known experimental toxicological data. Based on a very large number of predetermined descriptors, a...

  9. Overview: Progression-Free Survival as an Endpoint in Clinical Trials with Solid Tumors

    PubMed Central

    Korn, Ronald L.; Crowley, John J.

    2013-01-01

    Progression-free survival (PFS) is increasingly used as an important and even a primary endpoint in randomized cancer clinical trials in the evaluation of patients with solid tumors, because of both practical and clinical considerations. Although in its simplest form PFS is the time from randomization to a pre-defined endpoint, there are many factors that can influence the exact moment of when disease progression is recorded. In this overview, we review the circumstances that can devalue the use of PFS as a primary endpoint, and attempt to provide a pathway for a future desired state when PFS will become not just a secondary alternative to overall survival but rather an endpoint of choice. PMID:23669420

  10. Endpoint behavior of the pion distribution amplitude in QCD sum rules with nonlocal condensates

    SciTech Connect

    Mikhailov, S. V.; Pimikov, A. V.; Stefanis, N. G.

    2010-09-01

    Starting from the QCD sum rules with nonlocal condensates for the pion distribution amplitude, we derive another sum rule for its derivative and its ''integral derivatives''--defined in this work. We use this new sum rule to analyze the fine details of the pion distribution amplitude in the endpoint region x{approx}0. The results for endpoint-suppressed and flattop (or flatlike) pion distribution amplitudes are compared with those we obtained with differential sum rules by employing two different models for the distribution of vacuum-quark virtualities. We determine the range of values of the derivatives of the pion distribution amplitude and show that endpoint-suppressed distribution amplitudes lie within this range, while those with endpoint enhancement--flat-type or Chernyak-Zhitnitsky like--yield values outside this range.

  11. Potential of patient-reported outcomes as nonprimary endpoints in clinical trials

    PubMed Central

    2013-01-01

    Background The purpose of this research was to fully explore the impact of endpoint type (primary vs. nonprimary) on decisions related to patient-reported outcome (PRO) labeling claims supported by PRO measures and to determine if nonprimary PRO endpoints are being fully optimized. This review examines the use of PROs as both primary and nonprimary endpoints in support of demonstration of treatment benefit of new molecular entities (NMEs) and biologic license applications (BLAs) in the United States in the years 2000 to 2012. Methods All NMEs and BLAs approved by the Food and Drug Administration (FDA) between January 2000 and June 2012 were identified using the FDA Drug Approval Reports Web page. Generic products granted tentative approvals were excluded. For all identified products, medical review sections from publicly available drug approval packages were reviewed to identify PRO endpoint status. Product labels (indication, clinical trials sections) were reviewed to determine the number and type of PRO claim. Results A total of 308 NMEs/BLAs were identified. Of these, 70 NMEs/BLAs (23%) were granted PRO claims. The majority of product claims were for disease- or condition-specific signs and symptoms. Of the 70 products with PRO claims, a PRO was a primary endpoint for the vast majority (57 [81%]). A total of 19 of the 70 products were granted a PRO claim based on a nonprimary endpoint. While nonprimary endpoints were used most often to support claims of improved signs or symptoms, nonprimary endpoints were much more likely to support claims of higher order impacts. Conclusions Successful PRO labeling claims are typically based on primary endpoints assessing signs and symptoms. Based on this research, studies with PROs as primary endpoints are far more likely to facilitate positive regulatory review and acceptance of PROs in support of labeling claims. Although inclusion of PROs as nonprimary endpoints in clinical trials has its challenges, recent PRO labels

  12. Autonomous Sub-Pixel Satellite Track Endpoint Determination for Space Based Images

    SciTech Connect

    Simms, L M

    2011-03-07

    An algorithm for determining satellite track endpoints with sub-pixel resolution in spaced-based images is presented. The algorithm allows for significant curvature in the imaged track due to rotation of the spacecraft capturing the image. The motivation behind the subpixel endpoint determination is first presented, followed by a description of the methodology used. Results from running the algorithm on real ground-based and simulated spaced-based images are shown to highlight its effectiveness.

  13. Postexposure feeding depression: a new toxicity endpoint for use in laboratory studies with Daphnia magna.

    PubMed

    McWilliam, Ruth A; Baird, Donald J

    2002-06-01

    In situ bioassays with daphnids currently employ lethality as an endpoint, and although sublethal responses (reproduction and feeding rate) can be measured in the field, such endpoints pose major practical challenges. Previous studies have indicated that Daphnia magna exposed to toxic substances can exhibit delayed recovery in feeding behavior (postexposure feeding depression). This simple, robust response has the potential to be an ecologically relevant and potentially diagnostic endpoint. This study developed and tested the use of postexposure feeding depression as a toxicity endpoint in the laboratory environment. First, replicate numbers were manipulated to produce statistically reliable results. Second, postexposure feeding depression in D. magna was studied under laboratory conditions, by employing toxic substances with differing modes of action. Although most substances caused feeding inhibition during direct exposure, not all substances produced postexposure feeding depression. However, the use of lethality as a supplementary endpoint provided an alternative measure when no feeding depression was apparent after exposure. In combination, these endpoints offer a potentially more sensitive, ecologically relevant alternative to the use of lethality alone for in situ bioassay studies. PMID:12069303

  14. Evaluation of three soil toxicity tests used to monitor acceptable endpoints

    SciTech Connect

    Brinkmann, M.; Stroo, H.; Leuschner, A.; Leuteritz, D.; Stromberg, M.; Brourman, M.

    1995-12-31

    Three terrestrial toxicity tests were used to evaluate the efficacy of biological treatment of creosote and pentachlorophenol impacted soils at a Superfund site. Microtox, 5-day lettuce seed, and 14-day earthworm toxicity tests were performed on 10 soil samples at the beginning and end of 3 months of land treatment. Secondary endpoints of root length and earthworm weight loss were also evaluated. EC50 and LC50 values were calculated using a Trimmed Logit Statistical Program and compared to toxicity of 10 background samples collected from the site. Results for initial soils demonstrated toxicity with three of the five endpoints. End treatment results showed no measurable toxicity using all endpoints. Toxicity testing results are critical for obtaining regulatory approval for the full-scale treatment system. Post treatment closure requirements for the site will be based on bioassay results. Evaluation of the three tests used showed the Microtox test to be the most sensitive to this type of toxicity. Lettuce seed germination results were the least sensitive of the three primary endpoints chosen. Of the secondary endpoint criteria, root length demonstrated reliable EC50 values and showed toxicity trends similar to Microtox and earthworm tests. The earthworm weight loss endpoint was not a useful toxicity measurement at 14 days.

  15. Physiological and lavage fluid cytological and biochemical endpoints of toxicity in the rat

    SciTech Connect

    Lehnert, B.E.

    1992-01-01

    Exposure of the respiratory tract to toxic materials can result in a variety of physiologic disturbances that can serve as endpoints of toxicity. In addition to a brief review of commonly assessed physiologic endpoints, attention is given in the first component of this report to the use of both nose breathing and mouth'' breathing rats in toxicity studies that involve measurements of ventilatory functional changes in response to test atmospheres. Additionally, the usefulness of maximum oxygen consumption, or VO[sub 2max], as a physiologic endpoint of toxicity that uses exercising rats after exposure to test atmospheres is described, along with an introduction to post-exposure exercise as an important behavioral activity that can markedly impact on the severity of acute lung injury caused by pneumoedematogenic materials. The second component of this report focuses on bronchoalveolar lavage and cytological and biochemical endpoints that can be assessed in investigations of the toxicities of test materials. As will be shown herein, some of the biochemical endpoints of toxicity, especially, can sensitively detect subtle injury to the lower respiratory tract that may escape detection by changes in some other conventional endpoints of toxicity, including lung gravimetric increases and histopathological alterations.

  16. Physiological and lavage fluid cytological and biochemical endpoints of toxicity in the rat

    SciTech Connect

    Lehnert, B.E.

    1992-12-31

    Exposure of the respiratory tract to toxic materials can result in a variety of physiologic disturbances that can serve as endpoints of toxicity. In addition to a brief review of commonly assessed physiologic endpoints, attention is given in the first component of this report to the use of both nose breathing and ``mouth`` breathing rats in toxicity studies that involve measurements of ventilatory functional changes in response to test atmospheres. Additionally, the usefulness of maximum oxygen consumption, or VO{sub 2max}, as a physiologic endpoint of toxicity that uses exercising rats after exposure to test atmospheres is described, along with an introduction to post-exposure exercise as an important behavioral activity that can markedly impact on the severity of acute lung injury caused by pneumoedematogenic materials. The second component of this report focuses on bronchoalveolar lavage and cytological and biochemical endpoints that can be assessed in investigations of the toxicities of test materials. As will be shown herein, some of the biochemical endpoints of toxicity, especially, can sensitively detect subtle injury to the lower respiratory tract that may escape detection by changes in some other conventional endpoints of toxicity, including lung gravimetric increases and histopathological alterations.

  17. Exploring the relationship between the causal-inference and meta-analytic paradigms for the evaluation of surrogate endpoints.

    PubMed

    Van der Elst, Wim; Molenberghs, Geert; Alonso, Ariel

    2016-04-15

    Nowadays, two main frameworks for the evaluation of surrogate endpoints, based on causal-inference and meta-analysis, dominate the scene. Earlier work showed that the metrics of surrogacy introduced in both paradigms are related, although in a complex way that is difficult to study analytically. In the present work, this relationship is further examined using simulations and the analysis of a case study. The results indicate that the extent to which both paradigms lead to similar conclusions regarding the validity of the surrogate, depends on a complex interplay between multiple factors like the ratio of the between and within trial variability and the unidentifiable correlations between the potential outcomes. All the analyses were carried out using the newly developed R package Surrogate, which is freely available via CRAN. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26612787

  18. Sensitivity to censored-at-random assumption in the analysis of time-to-event endpoints.

    PubMed

    Lipkovich, Ilya; Ratitch, Bohdana; O'Kelly, Michael

    2016-05-01

    Over the past years, significant progress has been made in developing statistically rigorous methods to implement clinically interpretable sensitivity analyses for assumptions about the missingness mechanism in clinical trials for continuous and (to a lesser extent) for binary or categorical endpoints. Studies with time-to-event outcomes have received much less attention. However, such studies can be similarly challenged with respect to the robustness and integrity of primary analysis conclusions when a substantial number of subjects withdraw from treatment prematurely prior to experiencing an event of interest. We discuss how the methods that are widely used for primary analyses of time-to-event outcomes could be extended in a clinically meaningful and interpretable way to stress-test the assumption of ignorable censoring. We focus on a 'tipping point' approach, the objective of which is to postulate sensitivity parameters with a clear clinical interpretation and to identify a setting of these parameters unfavorable enough towards the experimental treatment to nullify a conclusion that was favorable to that treatment. Robustness of primary analysis results can then be assessed based on clinical plausibility of the scenario represented by the tipping point. We study several approaches for conducting such analyses based on multiple imputation using parametric, semi-parametric, and non-parametric imputation models and evaluate their operating characteristics via simulation. We argue that these methods are valuable tools for sensitivity analyses of time-to-event data and conclude that the method based on piecewise exponential imputation model of survival has some advantages over other methods studied here. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26997353

  19. Measuring the micromechanical properties of embryonic tissues.

    PubMed

    Chevalier, Nicolas R; Gazguez, Elodie; Dufour, Sylvie; Fleury, Vincent

    2016-02-01

    Local mechanical properties play an important role in directing embryogenesis, both at the cell (differentiation, migration) and tissue level (force transmission, organ formation, morphogenesis). Measuring them is a challenge as embryonic tissues are small (μm to mm) and soft (0.1-10kPa). We describe here how glass fiber cantilevers can be fabricated, calibrated and used to apply small forces (0.1-10μN), measure contractile activity and assess the bulk tensile elasticity of embryonic tissue. We outline how pressure (hydrostatic or osmotic) can be applied to embryonic tissue to quantify stiffness anisotropy. These techniques can be assembled at low cost and with a minimal amount of equipment. We then present a protocol to prepare tissue sections for local elasticity and adhesion measurements using the atomic force microscope (AFM). We compare AFM nanoindentation maps of native and formaldehyde fixed embryonic tissue sections and discuss how the local elastic modulus obtained by AFM compares to that obtained with other bulk measurement methods. We illustrate all of the techniques presented on the specific example of the chick embryonic digestive tract, emphasizing technical issues and common pitfalls. The main purpose of this report is to make these micromechanical measurement techniques accessible to a wide community of biologists and biophysicists. PMID:26255132

  20. Computational fluid dynamics endpoints to characterize obstructive sleep apnea syndrome in children

    PubMed Central

    Luo, Haiyan; Persak, Steven C.; Sin, Sanghun; McDonough, Joseph M.; Isasi, Carmen R.; Arens, Raanan

    2013-01-01

    Computational fluid dynamics (CFD) analysis may quantify the severity of anatomical airway restriction in obstructive sleep apnea syndrome (OSAS) better than anatomical measurements alone. However, optimal CFD model endpoints to characterize or assess OSAS have not been determined. To model upper airway fluid dynamics using CFD and investigate the strength of correlation between various CFD endpoints, anatomical endpoints, and OSAS severity, in obese children with OSAS and controls. CFD models derived from magnetic resonance images were solved at subject-specific peak tidal inspiratory flow; pressure at the choanae was set by nasal resistance. Model endpoints included airway wall minimum pressure (Pmin), flow resistance in the pharynx (Rpharynx), and pressure drop from choanae to a minimum cross section where tonsils and adenoids constrict the pharynx (dPTAmax). Significance of endpoints was analyzed using paired comparisons (t-test or Wilcoxon signed rank test) and Spearman correlation. Fifteen subject pairs were analyzed. Rpharynx and dPTAmax were higher in OSAS than control and most significantly correlated to obstructive apnea-hypopnea index (oAHI), r = 0.48 and r = 0.49, respectively (P < 0.01). Airway minimum cross-sectional correlation to oAHI was weaker (r = −0.39); Pmin was not significantly correlated. CFD model endpoints based on pressure drops in the pharynx were more closely associated with the presence and severity of OSAS than pressures including nasal resistance, or anatomical endpoints. This study supports the usefulness of CFD to characterize anatomical restriction of the pharynx and as an additional tool to evaluate subjects with OSAS. PMID:24265282

  1. The Biomarker-Surrogacy Evaluation Schema: a review of the biomarker-surrogate literature and a proposal for a criterion-based, quantitative, multidimensional hierarchical levels of evidence schema for evaluating the status of biomarkers as surrogate endpoints.

    PubMed

    Lassere, Marissa N

    2008-06-01

    There are clear advantages to using biomarkers and surrogate endpoints, but concerns about clinical and statistical validity and systematic methods to evaluate these aspects hinder their efficient application. Section 2 is a systematic, historical review of the biomarker-surrogate endpoint literature with special reference to the nomenclature, the systems of classification and statistical methods developed for their evaluation. In Section 3 an explicit, criterion-based, quantitative, multidimensional hierarchical levels of evidence schema - Biomarker-Surrogacy Evaluation Schema - is proposed to evaluate and co-ordinate the multiple dimensions (biological, epidemiological, statistical, clinical trial and risk-benefit evidence) of the biomarker clinical endpoint relationships. The schema systematically evaluates and ranks the surrogacy status of biomarkers and surrogate endpoints using defined levels of evidence. The schema incorporates the three independent domains: Study Design, Target Outcome and Statistical Evaluation. Each domain has items ranked from zero to five. An additional category called Penalties incorporates additional considerations of biological plausibility, risk-benefit and generalizability. The total score (0-15) determines the level of evidence, with Level 1 the strongest and Level 5 the weakest. The term ;surrogate' is restricted to markers attaining Levels 1 or 2 only. Surrogacy status of markers can then be directly compared within and across different areas of medicine to guide individual, trial-based or drug-development decisions. This schema would facilitate communication between clinical, researcher, regulatory, industry and consumer participants necessary for evaluation of the biomarker-surrogate-clinical endpoint relationship in their different settings. PMID:17925313

  2. Endpoints for Neural Connectivity Including Neurite Outgrowth, Synapse Formation, and Function

    EPA Science Inventory

    A strategy for alternative methods for developmental neurotoxicity testing (DNT) focuses on assessment of chemical effects on conserved neurodevelopmental processes. The development of the brain is an integrated series of steps from the commitment of embryonic cells to become neu...

  3. Scaffolding for Three-Dimensional Embryonic Vasculogenesis

    NASA Astrophysics Data System (ADS)

    Kraehenbuehl, Thomas P.; Aday, Sezin; Ferreira, Lino S.

    Biomaterial scaffolds have great potential to support efficient vascular differentiation of embryonic stem cells. Vascular cell fate-specific biochemical and biophysical cues have been identified and incorporated into three-dimensional (3D) biomaterials to efficiently direct embryonic vasculogenesis. The resulting vascular-like tissue can be used for regenerative medicine applications, further elucidation of biophysical and biochemical cues governing vasculogenesis, and drug discovery. In this chapter, we give an overview on the following: (1) developmental cues for directed differentiation of human embryonic stem cells (hESCs) into vascular cells, (2) 3D vascular differentiation in embryoid bodies (EBs), (3) preparation of 3D scaffolds for the vascular differentiation of hESCs, and (4) the most significant studies combining scaffolding and hESCs for development of vascular-like tissue.

  4. The Dirac form factor predicts the Pauli form factor in the Endpoint Model

    NASA Astrophysics Data System (ADS)

    Dagaonkar, Sumeet K.; Jain, Pankaj; Ralston, John P.

    2016-07-01

    We compute the momentum-transfer dependence of the proton Pauli form factor F2 in the Endpoint overlap Model. We find the model correctly reproduces the scaling of the ratio of F2 with the Dirac form factor F1 observed at the Jefferson Laboratory. The calculation uses the leading-power, leading-twist Dirac structure of the quark light-cone wave function and the same endpoint dependence previously determined from the Dirac form factor F1. There are no parameters and no adjustable functions in the Endpoint Model's prediction for the scaling behavior of F2. The model's predicted momentum dependence of the ratio F2(Q2)/F1(Q2) is quite insensitive to the endpoint wave function, which explains why the observed ratio scales like 1 / Q down to rather low momentum transfers. We also fit the magnitude of this ratio by adjusting the parameters of the wave function. The Endpoint Model appears to be the only comprehensive model consistent with all form factor information as well as reproducing fixed-angle proton-proton scattering at large momentum transfer. Any one of the processes is capable of predicting the others.

  5. Individualizing endpoints in randomized clinical trials to better inform individual patient care: the TARGET proposal.

    PubMed

    Iwashyna, Theodore J; Deane, Adam M

    2016-01-01

    In practice, critical care practitioners individualize treatments and goals of care for each patient in light of that patient's acute and chronic pathophysiology, as well as their beliefs and values. Yet critical care researchers routinely measure one endpoint for all patients during randomized clinical trials (RCTs), eschewing any such individualization. More recent methodology work has explored the possibility that enrollment criteria in RCTs can be individualized, as can data analysis plans. Here we propose that the specific endpoints of a RCT can be individualized-that is, different patients within a single RCT might have different secondary endpoints measured. If done rigorously and objectively, based on pre-randomization data, such individualization of endpoints may improve the bedside usefulness of information obtained during a RCT, while perhaps also improving the power and efficiency of any RCT. We discuss the theoretical underpinnings of this proposal in light of related innovations in RCT design such as sliding dichotomies. We discuss what a full elaboration of such individualization would require, and outline a pragmatic initial step towards the use of "individualized secondary endpoints" in a large RCT evaluating optimal enteral nutrition targets in the critically ill. PMID:27485596

  6. Pollutant threshold concentration determination in marine ecosystems using an ecological interaction endpoint.

    PubMed

    Wang, Changyou; Liang, Shengkang; Guo, Wenting; Yu, Hua; Xing, Wenhui

    2015-09-01

    The threshold concentrations of pollutants are determined by extrapolating single-species effect data to community-level effects. This assumes the most sensitive endpoint of the life cycle of individuals and the species sensitivity distribution from single-species toxic effect tests, thus, ignoring the ecological interactions. The uncertainties due to this extrapolation can be partially overcome using the equilibrium point of a customized ecosystem. This method incorporates ecological interactions and integrates the effects on growth, survival, and ingestion into a single effect measure, the equilibrium point excursion in the customized ecosystem, in order to describe the toxic effects on plankton. A case study showed that the threshold concentration of copper calculated with the endpoint of the equilibrium point was 10 μg L(-1), which is significantly different from the threshold calculated with a single-species endpoint. The endpoint calculated using this method provides a more relevant measure of the ecological impact than any single individual-level endpoint. PMID:25982547

  7. Arsenate (As V) in water: quantitative sensitivity relationships among biomarker, ecotoxicity and genotoxicity endpoints.

    PubMed

    Silva, Valéria C; Almeida, Sônia M; Resgalla, Charrid; Masfaraud, Jean-François; Cotelle, Sylvie; Radetski, Claudemir M

    2013-06-01

    It is useful to test ecotoxicity and genotoxicity endpoints in the environmental impact assessment. Here, we compare and discuss ecotoxicity and genotoxicity effects in organisms in response to exposure to arsenate (As V) in solution. Eco(geno)toxicity responses in Aliivibrio fischeri, Lytechinus variegatus, Daphnia magna, Skeletonema costatum and Vicia faba were analyzed by assessing different endpoints: biomass growth, peroxidase activity, mitotic index, micronucleus frequency, and lethality in accordance with the international protocols. Quantitative sensitivity relationships (QSR) between these endpoints were established in order to rank endpoint sensitivity. The results for the QSR values based on the lowest observed effect concentration (LOEC) ratios varied from 2 (for ratio of root peroxidase activity to leaf peroxidase activity) to 2286 (for ratio of higher plant biomass growth to root peroxidase activity). The QSR values allowed the following sensitivity ranking to be established: higher plant enzymatic activity>daphnids≈echinoderms>bacteria≈algae>higher plant biomass growth. The LOEC values for the mitotic index and micronucleus frequency (LOEC=0.25mgAsL(-1)) were similar to the lowest LOEC values observed in aquatic organisms. This approach to the QSR of different endpoints could form the basis for monitoring and predicting early effects of pollutants before they give rise to significant changes in natural community structures. PMID:23597676

  8. Evaluating a surrogate endpoint at three levels, with application to vaccine development

    PubMed Central

    Gilbert, Peter B.; Qin, Li; Self, Steven G.

    2009-01-01

    SUMMARY Identification of an immune response to vaccination that reliably predicts protection from clinically significant infection, i.e. an immunological surrogate endpoint, is a primary goal of vaccine research. Using this problem of evaluating an immunological surrogate as an illustration, we describe a hierarchy of three criteria for a valid surrogate endpoint and statistical analysis frameworks for evaluating them. Based on a placebo-controlled vaccine efficacy trial, the first level entails assessing the correlation of an immune response with a study endpoint in the study groups, and the second level entails evaluating an immune response as a surrogate for the study endpoint that can be used for predicting vaccine efficacy for a setting similar to that of the vaccine trial. We show that baseline covariates, innovative study design, and a potential outcomes formulation can be helpful for this assessment. The third level entails validation of a surrogate endpoint via meta-analysis, where the goal is to evaluate how well the immune response can be used to predict vaccine efficacy for new settings (building bridges). A simulated vaccine trial and two example vaccine trials are presented, one supporting that certain anti-influenza antibody levels are an excellent surrogate for influenza illness and another supporting that certain anti-HIV antibody levels are not useful as a surrogate for HIV infection. PMID:17979212

  9. A new proportion measure of the treatment effect captured by candidate surrogate endpoints.

    PubMed

    Kobayashi, Fumiaki; Kuroki, Manabu

    2014-08-30

    The use of surrogate endpoints is expected to play an important role in the development of new drugs, as they can be used to reduce the sample size and/or duration of randomized clinical trials. Biostatistical researchers and practitioners have proposed various surrogacy measures; however, (i) most of these surrogacy measures often fall outside the range [0,1] without any assumptions, (ii) these surrogacy measures do not provide a cut-off value for judging a surrogacy level of candidate surrogate endpoints, and (iii) most surrogacy measures are highly variable; thus, the confidence intervals are often unacceptably wide. In order to solve problems (i) and (ii), we propose a new surrogacy measure, a proportion of the treatment effect captured by candidate surrogate endpoints (PCS), on the basis of the decomposition of the treatment effect into parts captured and non-captured by the candidate surrogate endpoints. In order to solve problem (iii), we propose an estimation method based on the half-range mode method with the bootstrap distribution of the estimated surrogacy measures. Finally, through numerical experiments and two empirical examples, we show that the PCS with the proposed estimation method overcomes these difficulties. The results of this paper contribute to the reliable evaluation of how much of the treatment effect is captured by candidate surrogate endpoints. PMID:24782344

  10. Considerations for Development of Surrogate Endpoints for Antifracture Efficacy of New Treatments in Osteoporosis: A Perspective

    PubMed Central

    Bouxsein, Mary L; Delmas, Pierre D

    2008-01-01

    Because of the broad availability of efficacious osteoporosis therapies, conduct of placebo-controlled trials in subjects at high risk for fracture is becoming increasing difficult. Alternative trial designs include placebo-controlled trials in patients at low risk for fracture or active comparator studies, both of which would require enormous sample sizes and associated financial resources. Another more attractive alternative is to develop and validate surrogate endpoints for fracture. In this perspective, we review the concept of surrogate endpoints as it has been developed in other fields of medicine and discuss how it could be applied in clinical trials of osteoporosis. We outline a stepwise approach and possible study designs to qualify a biomarker as a surrogate endpoint in osteoporosis and review the existing data for several potential surrogate endpoints to assess their success in meeting the proposed criteria. Finally, we suggest a research agenda needed to advance the development of biomarkers as surrogate endpoints for fracture in osteoporosis trials. To ensure optimal development and best use of biomarkers to accelerate drug development, continuous dialog among the health professionals, industry, and regulators is of paramount importance. PMID:18318643

  11. Human arm posture prediction in response to isometric endpoint forces.

    PubMed

    Davoudabadi Farahani, Saeed; Andersen, Michael Skipper; de Zee, Mark; Rasmussen, John

    2015-11-26

    The ability to predict the musculoskeletal response to external loads has multiple applications for the design of machines with a human interface and for the prediction of outcomes of musculoskeletal interventions. In this study, we applied an inverse-inverse dynamics technique to investigate its ability to predict arm posture in response to isometric hand forces. For each subject, we made a three-dimensional musculoskeletal model using the AnyBody Modelling System (AMS). Then, we had each subject-specific model hold a weight anteriorly to the right shoulder joint at a distance of half of the arm length. We selected the glenohumeral abduction angle (GHAA) as the only free parameter. Subsequently, we used inverse-inverse dynamics to find the optimal GHAA that minimised a performance criterion with physiological constraints. In this study, we investigated the performance of two different objective functions: summation of squared muscle activity (SSMA) and summation of squared normalised joint torques (SSNJT). To validate the simulation results, arm posture responses to different isometric downward hand forces were measured for six healthy male subjects. Five trials were performed for each loading condition. The results showed that, with an increase in hand load, there was a reduced GHAA in all subjects. Another interesting finding was that self-selected postures for lighter tasks varied more than postures for heavier tasks for all subjects. To understand this, we investigated the curvature of the objective function as a function of the load and observed an increased curvature with increased load. This may explain the reduced intra-subject variations observed for increasing loads. PMID:26482735

  12. Embryonic Stem Cell Patents and Human Dignity

    PubMed Central

    Resnik, David B.

    2009-01-01

    This article examines the assertion that human embryonic stem cells patents are immoral because they violate human dignity. After analyzing the concept of human dignity and its role in bioethics debates, this article argues that patents on human embryos or totipotent embryonic stem cells violate human dignity, but that patents on pluripotent or multipotent stem cells do not. Since patents on pluripotent or multipotent stem cells may still threaten human dignity by encouraging people to treat embryos as property, patent agencies should carefully monitor and control these patents to ensure that patents are not inadvertently awarded on embryos or totipotent stem cells. PMID:17922198

  13. Effects of bisphenol A on the embryonic development of sea urchin (Paracentrotus lividus).

    PubMed

    Ozlem, Cakal Arslan; Hatice, Parlak

    2008-06-01

    Bisphenol A (BPA), is one of the most important industrial chemicals synthesized for diverse applications. In this study, tests for embryotoxic and spermiotoxic effects of BPA were utilized in the sperms and embryos of the sea urchin Paracentrotus lividus. The sperm and eggs of sea urchins were exposed to increasing concentrations of BPA (300-3500 microg/L) under static conditions. The endpoints were successful sperm fertilization, larval malformations, developmental arrest, and embryonic/larval mortality. BPA concentration (300 microg/L) had spermiotoxic and embryotoxic effects on this species. A dose-response related reduction was observed in fertilization success and significant increases in the number of larvae with skeleton malformations at the pluteus stage when the sperms were exposed BPA. The embryotoxicity of BPA is concentration-dependent and significant growth reduction at the early life stages and an increase in larval malformations as skeleton deformities at the pluteus stage were observed. It can be concluded that BPA adversely affects the reproduction and embryonic developmental stages of the P. lividus and this is of great ecological importance due to the hazard at the population level. PMID:18214894

  14. Cervical spinal cord injury: tailoring clinical trial endpoints to reflect meaningful functional improvements

    PubMed Central

    Bond, Lisa M.; McKerracher, Lisa

    2014-01-01

    Cervical spinal cord injury (SCI) results in partial to full paralysis of the upper and lower extremities. Traditional primary endpoints for acute SCI clinical trials are too broad to assess functional recovery in cervical subjects, raising the possibility of false positive outcomes in trials for cervical SCI. Endpoints focused on the recovery of hand and arm control (e.g., upper extremity motor score, motor level change) show the most potential for use as primary outcomes in upcoming trials of cervical SCI. As the field moves forward, the most reliable way to ensure meaningful clinical testing in cervical subjects may be the development of a composite primary endpoint that measures both neurological recovery and functional improvement. PMID:25317162

  15. Radiation acquisition and RBF neural network analysis on BOF end-point control

    NASA Astrophysics Data System (ADS)

    Zhao, Qi; Wen, Hong-yuan; Zhou, Mu-chun; Chen, Yan-ru

    2008-12-01

    There are some problems in Basic Oxygen Furnace (BOF) steelmaking end-point control technology at present. A new BOF end-point control model was designed, which was based on the character of carbon oxygen reaction in Basic Oxygen Furnace steelmaking process. The image capture and transformation system was established by Video for Windows (VFW) library function, which is a video software development package promoted by Microsoft Corporation. In this paper, the Radial Basic Function (RBF) neural network model was established by using the real-time acquisition information. The input parameters can acquire easily online and the output parameter is the end-point time, which can compare with the actual value conveniently. The experience results show that the predication result is ideal and the experiment results show the model can work well in the steelmaking adverse environment.

  16. Update of OECD DART guidelines with endocrine disruptor relevant endpoints: Practical considerations.

    PubMed

    Beekhuijzen, Manon; van Otterdijk, Francois; Wieland, Willemien; van Tuyl, Miranda; Rijcken, Robert Pels; Peter, Birgit; Emmen, Harry

    2016-09-01

    In 1998, the OECD initiated a high-priority project aimed at revising existing test guidelines and developing new test guidelines for screening of potential endocrine disruptors. In 2011, OECD 443 was adopted, and in 2015 OECD 421 and OECD 422 were updated with endocrine disruptor relevant endpoints. A feasibility study for the enhancement of OECD 414 with endocrine disruptor relevant endpoints is currently ongoing. The addition of these endpoints is considered crucial for gaining more information on endocrine disruptor potency of tested chemicals, however it should be noted that these additions have a major impact on the study designs and give rise to several practical challenges. The aim of this review is to discuss important aspects of these challenging study designs and to share our knowledge on their implementation in our laboratory. Together, this review can be used as guidance for other laboratories, study monitors and registration officers. PMID:27063183

  17. Amplification of endpoint structure for new particle mass measurement at the LHC

    SciTech Connect

    Cho, Won Sang; Kim, Jihn E.; Kim, Ji-Hun

    2010-05-01

    We introduce a new collider variable, M{sub CT2}, named as constransverse mass. It is a mixture of 'stransverse mass (M{sub T2})' and 'contransverse mass (M{sub CT})' variables, where the usual endpoint structure of M{sub T2} distribution can be amplified in the M{sub CT2} basis by a large Jacobian factor which is controlled by a trial missing particle mass. Thus, the M{sub CT2} projection of events increases our observability to measure several important endpoints from new particle decays, which are usually expected to be buried by irreducible backgrounds with various systematic uncertainties at the LHC. In this paper we explain the phenomenology of endpoint amplification in M{sub CT2} projection, and describe how one may employ this variable to measure several meaningful mass constraints of new particles.

  18. Deep inelastic scattering near the endpoint in soft-collinear effective theory

    SciTech Connect

    Chay, Junegone; Kim, Chul

    2007-01-01

    We apply the soft-collinear effective theory to deep inelastic scattering near the endpoint region. The forward scattering amplitude and the structure functions are shown to factorize as a convolution of the Wilson coefficients, the jet functions, and the parton distribution functions. The behavior of the parton distribution functions near the endpoint region is considered. It turns out that it evolves with the Altarelli-Parisi kernel even in the endpoint region, and the parton distribution function can be factorized further into a collinear part and the soft Wilson line. The factorized form for the structure functions is obtained by the two-step matching, and the radiative corrections or the evolution for each factorized part can be computed in perturbation theory. We present the radiative corrections of each factorized part to leading order in {alpha}{sub s}, including the zero-bin subtraction for the collinear part.

  19. Swimming speed alteration in the early developmental stages of Paracentrotus lividus sea urchin as ecotoxicological endpoint.

    PubMed

    Morgana, Silvia; Gambardella, Chiara; Falugi, Carla; Pronzato, Roberto; Garaventa, Francesca; Faimali, Marco

    2016-04-01

    Behavioral endpoints have been used for decades to assess chemical impacts at concentrations unlikely to cause mortality. With recently developed techniques, it is possible to investigate the swimming behavior of several organisms under laboratory conditions. The aims of this study were: i) assessing for the first time the feasibility of swimming speed analysis of the early developmental stage sea urchin Paracentrotus lividus by an automatic recording system ii) investigating any Swimming Speed Alteration (SSA) on P. lividus early stages exposed to a chemical reference; iii) identifying the most suitable stage for SSA test. Results show that the swimming speed of all the developmental stages was easily recorded. The swimming speed was inhibited as a function of toxicant concentration. Pluteus were the most appropriate stage for evaluating SSA in P. lividus as ecotoxicological endpoint. Finally, swimming of sea urchin early stages represents a sensitive endpoint to be considered in ecotoxicological investigations. PMID:26826671

  20. General Information about Childhood Central Nervous System Embryonal Tumors

    MedlinePlus

    ... System Embryonal Tumors Treatment (PDQ®)–Patient Version General Information About Childhood Central Nervous System Embryonal Tumors Go ... in patients with a high-risk tumor. The information from tests and procedures done to detect (find) ...

  1. Effect of Pre-Fixation Delay and Freezing on Mink Testicular Endpoints for Environmental Research

    PubMed Central

    Spörndly-Nees, Ellinor; Ekstedt, Elisabeth; Magnusson, Ulf; Fakhrzadeh, Azadeh; Luengo Hendriks, Cris L.; Holm, Lena

    2015-01-01

    There is growing interest in using wild animals to monitor the real-life cocktail effect of environmental chemicals on male reproduction. However, practical difficulties, such as long distances to the laboratory, generally prolong the time between euthanisation and specimen handling. For instance, tissue fixation is often performed on frozen material or on material where deterioration has started, which may affect tissue morphology. This study examined the effect of pre-fixation delay and freezing on mink testicular endpoints in order to determine robust endpoints in suboptimally handled specimens. Sexually mature farmed mink (n=30) selected at culling were divided into six groups and subjected to different time intervals between euthanisation and fixation or freezing: 0 hours (fixed immediately post mortem), 6 hours, 18 hours, 30 hours, 42 hours, or frozen 6 hours post mortem and thawed overnight. Unaffected endpoints when pre-fixation storage was extended to 30 hours included: area and diameter of the seminiferous tubules, length and weight of the testes, and acrosomes marked with Gata-4. Epithelial height, Sertoli cells marked with Gata-4 and cell morphology were affected endpoints after 6 hours of storage. Freezing the tissue prior to fixation severely altered cell morphology and reduced testicular weight, tubular diameter and area. Morphological changes seen after 6 hours included shredded germ cells and excess cytoplasm in seminiferous tubular lumen, chromatin rearrangements and increased germ cell death. Extended delay before fixation and freezing affected many endpoints in the mink testicular tissue. Some of these endpoints may mimic chemically induced effects, which is important to consider when evaluating specimens from wild animals for environmental toxicity. PMID:25933113

  2. Quantifying Variability in Four U.S. Streams Using a Long-Term Dataset: Patterns in Biotic Endpoints

    NASA Astrophysics Data System (ADS)

    Flinders, Camille A.; McLaughlin, Douglas B.; Ragsdale, Renee L.

    2015-08-01

    Effective water resources assessment and management requires quantitative information on the variability of ambient and biological conditions in aquatic communities. Although it is understood that natural systems are variable, robust estimates of long-term variation in community-based structure and function metrics are rare in U.S. waters. We used a multi-year, seasonally sampled dataset from multiple sites ( n = 5-6) in four streams (Codorus Creek, PA; Leaf River, MS; McKenzie and Willamette Rivers, OR) to examine spatial and temporal variation in periphyton chlorophyll a, and fish and macroinvertebrate metrics commonly used in bioassessment programs. Within-site variation of macroinvertebrate metrics and benthic chlorophyll a concentration showed coefficient of variation ranging from 16 to 136 %. Scale-specific variability patterns (stream-wide, season, site, and site-season patterns) in standardized biotic endpoints showed that within-site variability patterns extended across sites with variability greatest in chlorophyll a and lowest in Hilsenhoff's Biotic Index. Across streams, variance components models showed that variance attributed to the interaction of space and time and sample variance accounted for the majority of variation in macroinvertebrate metrics and chlorophyll a, while most variation in fish metrics was attributed to sample variance. Clear temporal patterns in measured endpoints were rare and not specific to any one stream or assemblage, while apparent shifts in metric variability related to point source discharges were seen only in McKenzie River macroinvertebrate metrics in the fall. Results from this study demonstrate the need to consider and understand spatial, seasonal, and longer term variability in the development of bioassessment programs and subsequent decisions.

  3. Order of the Roberge-Weiss endpoint (finite size transition) in QCD

    NASA Astrophysics Data System (ADS)

    D'Elia, Massimo; Sanfilippo, Francesco

    2009-12-01

    We consider the endpoint of the Roberge-Weiss (RW) first order transition line present for imaginary baryon chemical potentials. We remark that it coincides with the finite size transition relevant in the context of large Nc QCD and study its order in the theory with two degenerate flavors. The RW endpoint is first order in the limit of large and small quark masses, while it weakens for intermediate masses where it is likely in the Ising 3D universality class. Phenomenological implications and further speculations about the QCD phase diagram are discussed.

  4. A numerical method of finding potentiometric titration end-points by use of approximative spline functions.

    PubMed

    Ren, K

    1990-07-01

    A new numerical method of determining potentiometric titration end-points is presented. It consists in calculating the coefficients of approximative spline functions describing the experimental data (e.m.f., volume of titrant added). The end-point (the inflection point of the curve) is determined by calculating zero points of the second derivative of the approximative spline function. This spline function, unlike rational spline functions, is free from oscillations and its course is largely independent of random errors in e.m.f. measurements. The proposed method is useful for direct analysis of titration data and especially as a basis for construction of microcomputer-controlled automatic titrators. PMID:18964999

  5. Comparison of methods for accurate end-point detection of potentiometric titrations

    NASA Astrophysics Data System (ADS)

    Villela, R. L. A.; Borges, P. P.; Vyskočil, L.

    2015-01-01

    Detection of the end point in potentiometric titrations has wide application on experiments that demand very low measurement uncertainties mainly for certifying reference materials. Simulations of experimental coulometric titration data and consequential error analysis of the end-point values were conducted using a programming code. These simulations revealed that the Levenberg-Marquardt method is in general more accurate than the traditional second derivative technique used currently as end-point detection for potentiometric titrations. Performance of the methods will be compared and presented in this paper.

  6. Calculation of a velocity distribution from particle trajectory end-points.

    USGS Publications Warehouse

    Rasmussen, Lowell A.

    1983-01-01

    The longitudinal component of the velocity of a particle at or near a glacier surface is considered, its position as a function of time being termed its trajectory. Functional relationships are derived for obtaining the trajectory from the spatial distribution of velocity and for obtaining the velocity distribution from the trajectory. It is established that the trajectory end-points impose only an integral condition on the velocity distribution and that no individual point on the velocity distribution can be determined if only the end-points are known.-from Author

  7. Order of the Roberge-Weiss endpoint (finite size transition) in QCD

    SciTech Connect

    D'Elia, Massimo; Sanfilippo, Francesco

    2009-12-01

    We consider the endpoint of the Roberge-Weiss (RW) first order transition line present for imaginary baryon chemical potentials. We remark that it coincides with the finite size transition relevant in the context of large N{sub c} QCD and study its order in the theory with two degenerate flavors. The RW endpoint is first order in the limit of large and small quark masses, while it weakens for intermediate masses where it is likely in the Ising 3D universality class. Phenomenological implications and further speculations about the QCD phase diagram are discuss0008.

  8. ANALYSIS OF CHICKEN EMBRYONIC GONAD ESTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have sequenced 11,842 cDNA clones from the embryonic gonad cDNA library to generate 10,294 sequences. The EST data described in this paper have been submitted to the NCBI dbEST under accession numbers CV852525 CV862818. The unique sequences of the EST data resulted in a total of 4,384 sequences w...

  9. Orbital embryonal rhabdomyosarcoma with metastasis in a young dog.

    PubMed

    Kato, Y; Notake, H; Kimura, J; Murakami, M; Hirata, A; Sakai, H; Yanai, T

    2012-01-01

    A 2-year-old male Welsh corgi dog was brought to an animal hospital because of left upper eyelid enlargement with lachrymal gland protrusion. The lachrymal and orbital cavity mass was removed surgically. Microscopically, the orbital mass consisted of a mixture of large rhabdomyoblastic and small round tumour cells. Immunohistochemically, the rhabdomyoblastic cells expressed desmin and myoglobin and the small round cells expressed desmin, myogenin and MyoD1. A diagnosis of embryonal rhabdomyosarcoma (ERS) was made. One month later, multiple masses throughout the body were identified, in particular around the cervical region. One of these lesions was sampled and diagnosed as metastatic ERS. The dog died 84 days after the time of first admission. PMID:22304975

  10. Three-dimensional bioprinting of rat embryonic neural cells.

    PubMed

    Lee, Wonhye; Pinckney, Jason; Lee, Vivian; Lee, Jong-Hwan; Fischer, Krisztina; Polio, Samuel; Park, Je-Kyun; Yoo, Seung-Schik

    2009-05-27

    We present a direct cell printing technique to pattern neural cells in a three-dimensional (3D) multilayered collagen gel. A layer of collagen precursor was printed to provide a scaffold for the cells, and the rat embryonic neurons and astrocytes were subsequently printed on the layer. A solution of sodium bicarbonate was applied to the cell containing collagen layer as nebulized aerosols, which allowed the gelation of the collagen. This process was repeated layer-by-layer to construct the 3D cell-hydrogel composites. Upon characterizing the relationship between printing resolutions and the growth of printed neural cells, single/multiple layers of neural cell-hydrogel composites were constructed and cultured. The on-demand capability to print neural cells in a multilayered hydrogel scaffold offers flexibility in generating artificial 3D neural tissue composites. PMID:19369905

  11. Gene expression dynamics during embryonic development in rainbow trout

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The supply of maternal RNAs in fertilized egg and activation of embryonic genome during maternal-zygotic transition (MZT) are important for normal embryonic development. In order to identify genes and gene products that are essential in the regulation of embryonic development in rainbow trout, RNA-S...

  12. Sourcing human embryos for embryonic stem cell lines: problems & perspectives.

    PubMed

    Mehta, Rajvi H

    2014-11-01

    The ability to successfully derive human embryonic stem cells (hESC) lines from human embryos following in vitro fertilization (IVF) opened up a plethora of potential applications of this technique. These cell lines could have been successfully used to increase our understanding of human developmental biology, transplantation medicine and the emerging science of regenerative medicine. The main source for human embryos has been 'discarded' or 'spare' fresh or frozen human embryos following IVF. It is a common practice to stimulate the ovaries of women undergoing any of the assisted reproductive technologies (ART) and retrieve multiple oocytes which subsequently lead to multiple embryos. Of these, only two or maximum of three embryos are transferred while the rest are cryopreserved as per the decision of the couple. in case a couple does not desire to 'cryopreserve' their embryos then all the embryos remaining following embryo transfer can be considered 'spare' or if a couple is no longer in need of the 'cryopreserved' embryos then these also can be considered as 'spare'. But, the question raised by the ethicists is, "what about 'slightly' over-stimulating a woman to get a few extra eggs and embryos? The decision becomes more difficult when it comes to 'discarded' embryos. As of today, the quality of the embryos is primarily assessed based on morphology and the rate of development mainly judged by single point assessment. Despite many criteria described in the literature, the quality assessment is purely subjective. The question that arises is on the decision of 'discarding' embryos. What would be the criteria for discarding embryos and the potential 'use' of ESC derived from the 'abnormal appearing' embryos? This paper discusses some of the newer methods to procure embryos for the derivation of embryonic stem cell lines which will respect the ethical concerns but still provide the source material. PMID:25673530

  13. Sourcing human embryos for embryonic stem cell lines: Problems & perspectives

    PubMed Central

    Mehta, Rajvi H.

    2014-01-01

    The ability to successfully derive human embryonic stem cells (hESC) lines from human embryos following in vitro fertilization (IVF) opened up a plethora of potential applications of this technique. These cell lines could have been successfully used to increase our understanding of human developmental biology, transplantation medicine and the emerging science of regenerative medicine. The main source for human embryos has been ‘discarded’ or ‘spare’ fresh or frozen human embryos following IVF. It is a common practice to stimulate the ovaries of women undergoing any of the assisted reproductive technologies (ART) and retrieve multiple oocytes which subsequently lead to multiple embryos. Of these, only two or maximum of three embryos are transferred while the rest are cryopreserved as per the decision of the couple. In case a couple does not desire to ‘cryopreserve’ their embryos then all the embryos remaining following embryo transfer can be considered ‘spare’ or if a couple is no longer in need of the ‘cryopreserved’ embryos then these also can be considered as ‘spare’. But, the question raised by the ethicists is, “what about ‘slightly’ over-stimulating a woman to get a few extra eggs and embryos? The decision becomes more difficult when it comes to ‘discarded’ embryos. As of today, the quality of the embryos is primarily assessed based on morphology and the rate of development mainly judged by single point assessment. Despite many criteria described in the literature, the quality assessment is purely subjective. The question that arises is on the decision of ‘discarding’ embryos. What would be the criteria for discarding embryos and the potential ‘use’ of ESC derived from the ‘abnormal appearing’ embryos? This paper discusses some of the newer methods to procure embryos for the derivation of embryonic stem cell lines which will respect the ethical concerns but still provide the source material. PMID:25673530

  14. Group-Sequential Strategies in Clinical Trials with Multiple Co-Primary Outcomes

    PubMed Central

    Hamasaki, Toshimitsu; Asakura, Koko; Evans, Scott R; Sugimoto, Tomoyuki; Sozu, Takashi

    2015-01-01

    We discuss the decision-making frameworks for clinical trials with multiple co-primary endpoints in a group-sequential setting. The decision-making frameworks can account for flexibilities such as a varying number of analyses, equally or unequally spaced increments of information and fixed or adaptive Type I error allocation among endpoints. The frameworks can provide efficiency, i.e., potentially fewer trial participants, than the fixed sample size designs. We investigate the operating characteristics of the decision-making frameworks and provide guidance on constructing efficient group-sequential strategies in clinical trials with multiple co-primary endpoints. PMID:25844122

  15. 77 FR 49447 - Endpoints for Clinical Trials in Kidney Transplantation; Public Workshop

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-16

    ... HUMAN SERVICES Food and Drug Administration Endpoints for Clinical Trials in Kidney Transplantation... trials of drugs and therapeutic biologics in kidney transplantation. This public workshop is intended to... evaluate patient and allograft outcome in clinical trials of kidney transplantation. The meeting...

  16. 78 FR 73199 - Draft Guidance for Industry on Bioequivalence Studies With Pharmacokinetic Endpoints for Drugs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-05

    ...The Food and Drug Administration (FDA) is announcing the availability of a draft guidance for industry entitled ``Bioequivalence Studies With Pharmacokinetic Endpoints for Drugs Submitted Under an ANDA.'' This guidance provides recommendations to applicants planning to include bioequivalence (BE) information in abbreviated new drug applications (ANDAs) and ANDA supplements. The guidance......

  17. [Change of Regulatory Requirement on Cohort Grouping and Endpoint Seting for Intervertebral Fusion Device Clinical Trial].

    PubMed

    Guo Xiaolei

    2015-07-01

    Combining technical requirement from main international administration and status quo of China administration, current regulatory requirement on clinical trail of conventional intervertebral fusion devices has been simplified. Cervical, thoracic and lumbar cases can be grouped into the same cohort, and primary endpoints are mainly based on imageology rather than clinical score. This is an attempt to rationally lessen industrial burdensome. PMID:26665950

  18. Aggregate entropy scoring for quantifying activity across endpoints with irregular correlation structure.

    PubMed

    Zhang, Guozhu; Marvel, Skylar; Truong, Lisa; Tanguay, Robert L; Reif, David M

    2016-07-01

    Robust computational approaches are needed to characterize systems-level responses to chemical perturbations in environmental and clinical toxicology applications. Appropriate characterization of response presents a methodological challenge when dealing with diverse phenotypic endpoints measured using in vivo systems. In this article, we propose an information-theoretic method named Aggregate Entropy (AggE) and apply it to scoring multiplexed, phenotypic endpoints measured in developing zebrafish (Danio rerio) across a broad concentration-response profile for a diverse set of 1060 chemicals. AggE accurately identified chemicals with significant morphological effects, including single-endpoint effects and multi-endpoint responses that would have been missed by univariate methods, while avoiding putative false-positives that confound traditional methods due to irregular correlation structure. By testing AggE in a variety of high-dimensional real and simulated datasets, we have characterized its performance and suggested implementation parameters that can guide its application across a wide range of experimental scenarios. PMID:27132190

  19. Recent Developments in Whole Sediment Toxicity Identification Evaluations: Innovations in Manipulations and Endpoints

    EPA Science Inventory

    Whole sediment Toxicity Identification Evaluation (TIE) methods were developed primarily in the late 1990s and early 2000s in research programs dedicated to developing manipulations and endpoints to characterize and identify causes of toxicity to benthic freshwater and marine org...

  20. Can joint sound assess soft and hard endpoints of the Lachman test?: A preliminary study.

    PubMed

    Hattori, Koji; Ogawa, Munehiro; Tanaka, Kazunori; Matsuya, Ayako; Uematsu, Kota; Tanaka, Yasuhito

    2016-05-12

    The Lachman test is considered to be a reliable physical examination for anterior cruciate ligament (ACL) injury. Patients with a damaged ACL demonstrate a soft endpoint feeling. However, examiners judge the soft and hard endpoints subjectively. The purpose of our study was to confirm objective performance of the Lachman test using joint auscultation. Human and porcine knee joints were examined. Knee joint sound during the Lachman test (Lachman sound) was analyzed by fast Fourier transformation. As quantitative indices of Lachman sound, the peak sound as the maximum relative amplitude (acoustic pressure) and its frequency were used. The mean Lachman peak sound for healthy volunteer knees was 86.9 ± 12.9 Hz in frequency and -40 ± 2.5 dB in acoustic pressure. The mean Lachman peak sound for intact porcine knees was 84.1 ± 9.4 Hz and -40.5 ± 1.7 dB. Porcine knees with ACL deficiency had a soft endpoint feeling during the Lachman test. The Lachman peak sounds of porcine knees with ACL deficiency were dispersed into four distinct groups, with center frequencies of around 40, 160, 450, and 1600. The Lachman peak sound was capable of assessing soft and hard endpoints of the Lachman test objectively. PMID:27175472

  1. Developing ecosystem services-based assessment endpoints for determining ecological risks to estuarine environments

    EPA Science Inventory

    Current U.S. EPA ecological risk assessment (ERA) guidance defines an assessment endpoint (AE) as an explicit expression of the environmental value that is to be protected, and recommends that AEs are selected based on ecological relevance, susceptibility to known or potential st...

  2. Shape and Steepness of Toxicological Dose-Response Relationships of Continuous Endpoints

    EPA Science Inventory

    A re-analysis of a large number of historical dose-response data for continuous endpoints indicates that an exponential or a Hill model with four parameters both adequately describe toxicological dose-responses. The four parameters relate to the background response, the potency o...

  3. Coulometric Titration of Ethylenediaminetetraacetate (EDTA) with Spectrophotometric Endpoint Detection: An Experiment for the Instrumental Analysis Laboratory

    ERIC Educational Resources Information Center

    Williams, Kathryn R.; Young, Vaneica Y.; Killian, Benjamin J.

    2011-01-01

    Ethylenediaminetetraacetate (EDTA) is commonly used as an anticoagulant in blood-collection procedures. In this experiment for the instrumental analysis laboratory, students determine the quantity of EDTA in commercial collection tubes by coulometric titration with electrolytically generated Cu[superscript 2+]. The endpoint is detected…

  4. Predictive Signatures from ToxCast Data for Chronic, Developmental and Reproductive Toxicity Endpoints

    EPA Science Inventory

    The EPA ToxCast program is using in vitro assay data and chemical descriptors to build predictive models for in vivo toxicity endpoints. In vitro assays measure activity of chemicals against molecular targets such as enzymes and receptors (measured in cell-free and cell-based sys...

  5. QUANTITATIVE STRUCTURE ACTIVITY RELATIONSHIP (QSAR) MODELS TO PREDICT CHEMICAL TOXICITY FOR VARIOUS HEALTH ENDPOINTS

    EPA Science Inventory

    Although ranking schemes based on exposure and toxicity have been developed to aid in the prioritization of research funds for identifying chemicals of regulatory concern, there are significant gaps in the availability of experimental toxicity data for most health endpoints. Pred...

  6. 76 FR 51993 - Draft Guidance for Industry on Standards for Clinical Trial Imaging Endpoints; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-19

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry on Standards for Clinical Trial... entitled ``Standards for Clinical Trial Imaging Endpoints.'' The purpose of this draft guidance is to... products. The draft guidance describes standards sponsors can use to ensure that clinical trial...

  7. 78 FR 46351 - Trial Designs and Endpoints for Liver Disease Secondary to Nonalcoholic Steatohepatitis; Public...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ...The Food and Drug Administration's (FDA's) Center for Drug Evaluation and Research in cosponsorship with the American Association for the Study of Liver Diseases (AASLD) is announcing a 2-day public workshop entitled ``Trial Designs and Endpoints for Liver Disease Secondary to Nonalcoholic fatty liver disease (NAFLD).'' There are no approved treatments for NAFLD and its complications of......

  8. Detecting Blending End-Point Using Mean Squares Successive Difference Test and Near-Infrared Spectroscopy.

    PubMed

    Khorasani, Milad; Amigo, José M; Bertelsen, Poul; Van Den Berg, Frans; Rantanen, Jukka

    2015-08-01

    An algorithm based on mean squares successive difference test applied to near-infrared and principal component analysis scores was developed to monitor and determine the blending profile and to assess the end-point in the statistical stabile phase. Model formulations consisting of an active compound (acetylsalicylic acid), together with microcrystalline cellulose and two grades of calcium carbonate with dramatically different particle shapes, were prepared. The formulation comprising angular-shaped calcium carbonate reached blending end-point slower when compared with the formulation comprising equant-shaped calcium carbonate. Utilizing the ring shear test, this distinction in end-point could be related to the difference in flowability of the formulations. On the basis of the two model formulations, a design of experiments was conducted to characterize the blending process by studying the effect of CaCO3 grades and fill level of the bin on blending end-point. Calcium carbonate grades, fill level, and their interaction were shown to have a significant impact on the blending process. PMID:26094601

  9. Second critical endpoint in the peridotite-H2O system

    NASA Astrophysics Data System (ADS)

    Mibe, Kenji; Kanzaki, Masami; Kawamoto, Tatsuhiko; Matsukage, Kyoko N.; Fei, Yingwei; Ono, Shigeaki

    2007-03-01

    The second critical endpoint in the peridotite-H2O system has been determined using an X-ray radiography technique together with a Kawai-type, double-stage, multianvil system driven by DIA-type cubic press (SPEED-1500) installed at SPring-8, Japan. The pressure of the second critical endpoint was determined by the appearance and disappearance of round shape in the radiographic images with changing the experimental pressure. In the experiments up to 3.6 GPa, two fluid phases (i.e., aqueous fluid and hydrous silicate melt) were observed. At 4.0 GPa, however, we could not distinguish these two phases in the radiographic images. These observations indicate the second critical endpoint occurs at around 3.8 GPa and 1000°C (corresponding to a depth of ˜110 km) in the peridotite-H2O system. Our experimental results suggest that hydrous silicate melt and aqueous fluid in the Earth's mantle become indistinguishable from each other and that melting temperature of hydrous mantle peridotite can no longer be defined beyond this critical condition. This position of the second critical endpoint could explain the previously observed drastic changes in composition and connectivity of aqueous fluid in mantle peridotite at around 3-4 GPa and could play an important role in magmatism and chemical evolution of the Earth's interior.

  10. Ozone risk assessment utilities (ORAMUS) user's manual and tutorial : Volume 2, Chronic health endpoints.

    SciTech Connect

    Clemmons, M. A.; Jusko, M. J.; Whitfield, R. G.

    1998-12-16

    The primary purpose of this manual is to provide instructions on how to install and use the ORAMUS (Ozone Risk AssessMent UtilitieS) software. ORAMUS is a DOS-based software system that allows you to calculate and view risk estimates for health effects attributable to short- and long-term exposure to tropospheric ozone. The system combines exposure estimates with exposure-response relationships and then calculates and displays estimates of the overall risk in the form of probability distributions. ORAMUS allows you to select from three basic models: headcount risk, benchmark risk, and hospital admissions. It calculates a wide range of risk results for 27 air quality scenarios, 9 urban areas, 33 acute health endpoints, 4 chronic health endpoints, and 3 populations of interest. This manual is a tutorial designed to guide you through a series of steps that will familiarize you with the features of the system. The manual consists of two volumes. Volume 1 addresses acute health endpoints, and Volume 2 covers chronic health endpoints. Acute results were used during the National Ambient Air Quality Standards review process for ozone. Chronic results were not used.

  11. Ozone risk assessment utilities (ORAMUS) user's manual and tutorial : Volume 1, Acute health endpoints.

    SciTech Connect

    Clemmons, M. A.; Jusko, M. J.; Whitfield, R. G.

    1998-12-16

    The primary purpose of this manual is to provide instructions on how to install and use the ORAMUS (Ozone Risk AssessMent UtilitieS) software. ORAMUS is a DOS-based software system that allows you to calculate and view risk estimates for health effects attributable to short- and long-term exposure to tropospheric ozone. The system combines exposure estimates with exposure-response relationships and then calculates and displays estimates of the overall risk in the form of probability distributions. ORAMUS allows you to select from three basic models: headcount risk, benchmark risk, and hospital admissions. It calculates a wide range of risk results for 27 air quality scenarios, 9 urban areas, 33 acute health endpoints, 4 chronic health endpoints, and 3 populations of interest. This manual is a tutorial designed to guide you through a series of steps that will familiarize you with the features of the system. The manual consists of two volumes. Volume 1 addresses acute health endpoints, and Volume 2 covers chronic health endpoints. Acute results were used during the National Ambient Air Quality Standards review process for ozone. Chronic results were not used.

  12. Selecting surrogate endpoints for estimating pesticide effects on avian reproductive success

    EPA Science Inventory

    A Markov chain nest productivity model (MCnest) has been developed for projecting the effects of a specific pesticide-use scenario on the annual reproductive success of avian species of concern. A critical element in MCnest is the use of surrogate endpoints, defined as measured ...

  13. EFFECTS OF COPPER ON COMMUNITY, FUNCTIONAL, AND BEHAVIORAL ENDPOINTS IN AN ARTIFICIAL STREAM STUDY

    EPA Science Inventory

    A study of the effects of copper on biota and behavioral endpoints was carried out at the U.S. EPA's Experimental Stream Facility (ESF), Milford OH. The objective of the study was to identify relationships between structural (macrobenthos and periphyton indices), functional (inte...

  14. Alternate Endpoints for Deep Vadose Zone Environments: Challenges, Opportunities, and Progress

    SciTech Connect

    Wellman, Dawn M.; Freshley, Mark D.; Truex, Michael J.; Lee, Michelle H.

    2013-02-24

    Current requirements for site remediation and closure are standards-based and are often overly conservative, costly, and in some cases, technically impractical to achieve. Use of risk-informed alternate endpoints provide a means to achieve remediation goals that are permitted by regulations and are protective of human health and the environment. Alternate endpoints enable establishing a path for cleanup that may include intermediate remedial milestones and transition points and/or regulatory alternatives to standards-based remediation. A framework is presented that is centered around developing and refining conceptual models in conjunction with assessing risks and potential endpoints as part of a system-based assessment that integrates site data with scientific understanding of processes that control the distribution and transport of contaminants in the subsurface and pathways to receptors. This system based assessment and subsequent implementation of the remediation strategy with appropriate monitoring are targeted at providing a holistic approach to addressing risks to human health and the environment. This holistic approach also enables effective predictive analysis of contaminant behavior to provide defensible criteria and data for making long-term decisions. Developing and implementing an alternate endpoint-based approach for remediation and waste site closure presents a number of challenges and opportunities. Categories of these challenges include scientific and technical, regulatory, institutional, and budget and resource allocation issues. Opportunities exist for developing and implementing systems-based approaches with respect to supportive characterization, monitoring, predictive modeling, and remediation approaches.

  15. Alternate Endpoints for Deep Vadose Zone Environments: Challenges, Opportunities, and Progress - 13036

    SciTech Connect

    Wellman, Dawn M.; Freshley, Mark D.; Truex, Michael J.; Lee, M. Hope

    2013-07-01

    Current requirements for site remediation and closure are standards-based and are often overly conservative, costly, and in some cases, technically impractical to achieve. Use of risk-informed alternate endpoints provide a means to achieve remediation goals that are permitted by regulations and are protective of human health and the environment. Alternate endpoints enable establishing a path for cleanup that may include intermediate remedial milestones and transition points and/or regulatory alternatives to standards-based remediation. A framework is presented that is centered around developing and refining conceptual models in conjunction with assessing risks and potential endpoints as part of a system-based assessment that integrates site data with scientific understanding of processes that control the distribution and transport of contaminants in the subsurface and pathways to receptors. This system-based assessment and subsequent implementation of the remediation strategy with appropriate monitoring are targeted at providing a holistic approach to addressing risks to human health and the environment. This holistic approach also enables effective predictive analysis of contaminant behavior to provide defensible criteria and data for making long-term decisions. Developing and implementing an alternate endpoint-based approach for remediation and waste site closure presents a number of challenges and opportunities. Categories of these challenges include scientific and technical, regulatory, institutional, and budget and resource allocation issues. Opportunities exist for developing and implementing systems-based approaches with respect to supportive characterization, monitoring, predictive modeling, and remediation approaches. (authors)

  16. Deep Vadose Zone Remediation: Technical and Policy Challenges, Opportunities, and Progress in Achieving Cleanup Endpoints

    SciTech Connect

    Wellman, Dawn M.; Freshley, Mark D.; Truex, Michael J.; Lee, Michelle H.

    2013-02-24

    Current requirements for site remediation and closure are standards-based and are often overly conservative, costly, and in some cases, technically impractical. Use of risk-informed alternate endpoints provides a means to achieve remediation goals that are permitted by regulations and are protective of human health and the environment. Alternate endpoints enable the establishment of a path for cleanup that may include intermediate remedial milestones and transition points and/or regulatory alternatives to standards-based remediation. A framework is presented that is centered around developing and refining conceptual models in conjunction with assessing risks and potential endpoints as part of a system-based assessment that integrates site data with scientific understanding of processes that control the distribution and transport of contaminants in the subsurface and pathways to receptors. This system-based assessment and subsequent implementation of the remediation strategy with appropriate monitoring are targeted at providing a holistic approach to addressing risks to human health and the environment. This holistic approach also enables effective predictive analysis of contaminant behavior to provide defensible criteria and data for making long-term decisions. Developing and implementing an alternate endpoint-based approach for remediation and waste site closure presents a number of challenges and opportunities. Categories of these challenges include scientific and technical, regulatory, institutional, and budget and resource allocation issues. Opportunities exist for developing and implementing systems-based approaches with respect to supportive characterization, monitoring, predictive modeling, and remediation approaches.

  17. A novel test to compare two treatments based on endpoints involving both nonfatal and fatal events

    PubMed Central

    Potthoff, Richard F.; Halabi, Susan

    2015-01-01

    In a clinical trial comparing two treatment groups, one commonly-used endpoint is time to death. Another is time until the first nonfatal event (if there is one) or until death (if not). Both endpoints have drawbacks. The wrong choice may adversely affect the value of the study, by impairing power if deaths are too few (with the first endpoint) or by lessening the role of mortality if not (with the second endpoint). We propose a compromise that provides a simple test based on the time to death if the patient has died, or time since randomization augmented by an increment otherwise. The test applies the ordinary two-sample Wilcoxon statistic to these values. The formula for the increment (the same for experimental and control patients) must be specified before the trial starts. In the simplest (and perhaps most useful) case, the increment assumes only two values, according to whether or not the (surviving) patient had a nonfatal event. More generally, the increment depends on the time of the first nonfatal event, if any, and the time since randomization. The test has correct Type I error even though it does not handle censoring in a customary way. For conditions where investigators would face no easy (advance) choice between the two older tests, simulation results favor the new test. An example using a renal-cancer trial is presented. PMID:25894200

  18. Correlates of protection for rotavirus vaccines: Possible alternative trial endpoints, opportunities, and challenges

    PubMed Central

    Angel, Juana; Steele, A Duncan; Franco, Manuel A

    2014-01-01

    Rotavirus (RV) is a major vaccine-preventable killer of young children worldwide. Two RV vaccines are globally commercially available and other vaccines are in different stages of development. Due to the absence of a suitable correlate of protection (CoP), all RV vaccine efficacy trials have had clinical endpoints. These trials represent an important challenge since RV vaccines have to be introduced in many different settings, placebo-controlled studies are unethical due to the availability of licensed vaccines, and comparator assessments for new vaccines with clinical endpoints are very large, complex, and expensive to conduct. A CoP as a surrogate endpoint would allow predictions of vaccine efficacy for new RV vaccines and enable a regulatory pathway, contributing to the more rapid development of new RV vaccines. The goal of this review is to summarize experiences from RV natural infection and vaccine studies to evaluate potential CoP for use as surrogate endpoints for assessment of new RV vaccines, and to explore challenges and opportunities in the field. PMID:25483685

  19. LIFE CYCLE IMPACT ASSESSMENT WORKSHOP SUMMARY - MIDPOINTS VERSUS ENDPOINTS: THE SACRIFICES AND BENEFITS

    EPA Science Inventory

    On 5/25-26/2000 in Brighton, England, the third international workshop was held under the umbrella of UNEP addressing issues in Life Cycle Impact Assessment (LCIA). The workshop provided a forum for experts to discuss midpoint vs. endpoint modeling. Midpoints are considered to be...

  20. Population modelling to compare chronic external radiotoxicity between individual and population endpoints in four taxonomic groups.

    PubMed

    Alonzo, Frédéric; Hertel-Aas, Turid; Real, Almudena; Lance, Emilie; Garcia-Sanchez, Laurent; Bradshaw, Clare; Vives I Batlle, Jordi; Oughton, Deborah H; Garnier-Laplace, Jacqueline

    2016-02-01

    In this study, we modelled population responses to chronic external gamma radiation in 12 laboratory species (including aquatic and soil invertebrates, fish and terrestrial mammals). Our aim was to compare radiosensitivity between individual and population endpoints and to examine how internationally proposed benchmarks for environmental radioprotection protected species against various risks at the population level. To do so, we used population matrix models, combining life history and chronic radiotoxicity data (derived from laboratory experiments and described in the literature and the FREDERICA database) to simulate changes in population endpoints (net reproductive rate R0, asymptotic population growth rate λ, equilibrium population size Neq) for a range of dose rates. Elasticity analyses of models showed that population responses differed depending on the affected individual endpoint (juvenile or adult survival, delay in maturity or reduction in fecundity), the considered population endpoint (R0, λ or Neq) and the life history of the studied species. Among population endpoints, net reproductive rate R0 showed the lowest EDR10 (effective dose rate inducing 10% effect) in all species, with values ranging from 26 μGy h(-1) in the mouse Mus musculus to 38,000 μGy h(-1) in the fish Oryzias latipes. For several species, EDR10 for population endpoints were lower than the lowest EDR10 for individual endpoints. Various population level risks, differing in severity for the population, were investigated. Population extinction (predicted when radiation effects caused population growth rate λ to decrease below 1, indicating that no population growth in the long term) was predicted for dose rates ranging from 2700 μGy h(-1) in fish to 12,000 μGy h(-1) in soil invertebrates. A milder risk, that population growth rate λ will be reduced by 10% of the reduction causing extinction, was predicted for dose rates ranging from 24 μGy h(-1) in mammals to 1800 μGy h(-1) in

  1. Alternative Endpoints and Approaches Selected for the Remediation of Contaminated Groundwater at Complex Sites

    NASA Astrophysics Data System (ADS)

    Deeb, R. A.; Hawley, E.

    2011-12-01

    This presentation will focus on findings, statistics, and case studies from a recently-completed report for the Department of Defense's Environmental Security Technology Certification Program (ESTCP) (Project ER-0832) on alternative endpoints and alternative remedial strategies for groundwater remediation under a variety of Federal and state cleanup programs, including technical impracticability (TI) and other Applicable or Relevant and Appropriate Requirement (ARAR) waivers, state and local designations such as groundwater management zones, Alternate Concentration Limits (ACLs), use of monitored natural attenuation (MNA) over long timeframes, and more. The primary objective of the project was to provide environmental managers and regulators with tools, metrics, and information needed to evaluate alternative endpoints for groundwater remediation at complex sites. A statistical analysis of Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) sites receiving TI waivers will be presented as well as case studies of other types of alternative endpoints and alternative remedial strategies to illustrate the variety of approaches used at complex sites and the technical analyses used to predict and document cost, timeframe, and potential remedial effectiveness. Case studies provide examples of the flexible, site-specific, application of alternative endpoints and alternative remedial strategies that have been used in the past to manage and remediate groundwater contamination at complex sites. For example, at least 13 states consider some designation for groundwater containment in their corrective action policies, such as groundwater management zones, containment zones, and groundwater classification exemption areas. These designations typically indicate that groundwater contamination is present above permissible levels. Soil and groundwater within these zones are managed to protect human health and the environment. Lesson learned for the analyses

  2. Patient relevant endpoints in oncology: current issues in the context of early benefit assessment in Germany

    PubMed Central

    2014-01-01

    The German AMNOG healthcare reform includes a mandatory early-benefit-assessment (EBA) at launch. As per German social code, EBA is based on registration trials and includes evaluation of the patient-relevant effect of the new medicines compared to an appropriate comparator as defined by the Federal Joint Committee (G-BA). Current EBA decisions released have unveiled issues regarding the acceptance of some patient-relevant endpoints as G-BA and IQWiG are grading the endpoints, focusing on overall survival as the preferred endpoint in oncology. A taskforce of experienced German outcomes research, medical, health-technology assessment and biostatistics researchers in industry was appointed. After agreement on core assumptions, a draft position was prepared. Input on iterative versions was solicited from a panel of reviewers from industry and external stakeholders. Distinctive features of registration trials in oncology need to be considered when these studies form basis for EBA, especially in cancer-indications with long post-progression survival; and with several consecutive therapeutic options available post-progression. Ethical committees, caregivers and patients often demand cross-over-designs diluting the treatment-effect on overall survival. Regulatory authorities require evaluation of morbidity-related study endpoints including survival of patients without their disease getting worse (i.e., progression-free survival). Also, progression requires treatment-changes, another strong indicator for its relevance to patients. Based on specific guidelines and clinical trial programs that were developed to be consistent with regulatory guidance, endpoints in oncology are thoroughly evaluated in terms of their patient-relevance. This extensive knowledge and experience should be fully acknowledged during EBA when assessing the patient-relevant benefit of innovative medicines in oncology. JEL codes D61; H51; I18. PMID:24460706

  3. Linaclotide: Promising IBS-C Efficacy in an Era of Provisional Study Endpoints

    PubMed Central

    Sayuk, Gregory S.

    2013-01-01

    Recent disappointing developments in the pharmacotherapy of irritable bowel syndrome (IBS) have not dampened the enthusiasm surrounding linaclotide, a novel guanylate cyclase-C agonist for the management of constipation-predominant IBS (IBS-C). Two recent phase 3 studies reporting on a single, daily dose of linaclotide are presented in this issue of the American Journal of Gastroenterology. Importantly, these studies are the first to examine a provisional Food and Drug Administration (FDA) combined response endpoint for IBS-C, which mandates improvements of both abdominal pain and defecatory symptoms. Potential limitations of this FDA endpoint relate to a lack of inclusion of other potentially important IBS symptoms and an inability to directly compare findings with other recent IBS-C trials. Both studies successfully reached this endpoint in approximately one-third of study subjects, resulting in numbers needed to treat (NNT) of five to eight, to achieve an FDA responder. Individual symptom responses to linaclotide were seen in nearly 50% of participants, and potential explanations for these discrepancies when compared with the FDA endpoint are offered. Adequate relief measures also were assessed and, with NNTs of 3.4–6.8, compared favorably with other contemporary IBS-C studies. Overall, both linaclotide trials found the medication to be safe in terms of serious adverse events, though the secretagogue mechanism of action led to diarrhea in approximately one in five subjects. Together, these studies inspire several other important questions regarding linaclotide, including its role in the management of IBS-C relative to existing treatment options, such as lubiprostone. Greater clinical use of linaclotide will reveal whether the observed responses measured with the FDA provisional endpoint will translate into real-world experiences of improvement in IBS patients. “ In seeking absolute truth we aim at the unattainable and must be content with broken portions

  4. Linaclotide: promising IBS-C efficacy in an era of provisional study endpoints.

    PubMed

    Sayuk, Gregory S

    2012-11-01

    Recent disappointing developments in the pharmacotherapy of irritable bowel syndrome (IBS) have not dampened the enthusiasm surrounding linaclotide, a novel guanylate cyclase-C agonist for the management of constipation-predominant IBS (IBS-C). Two recent phase 3 studies reporting on a single, daily dose of linaclotide are presented in this issue of the American Journal of Gastroenterology. Importantly, these studies are the first to examine a provisional Food and Drug Administration (FDA) combined response endpoint for IBS-C, which mandates improvements of both abdominal pain and defecatory symptoms. Potential limitations of this FDA endpoint relate to a lack of inclusion of other potentially important IBS symptoms and an inability to directly compare findings with other recent IBS-C trials. Both studies successfully reached this endpoint in approximately one-third of study subjects, resulting in numbers needed to treat (NNT) of five to eight, to achieve an FDA responder. Individual symptom responses to linaclotide were seen in nearly 50% of participants, and potential explanations for these discrepancies when compared with the FDA endpoint are offered. Adequate relief measures also were assessed and, with NNTs of 3.4-6.8, compared favorably with other contemporary IBS-C studies. Overall, both linaclotide trials found the medication to be safe in terms of serious adverse events, though the secretagogue mechanism of action led to diarrhea in approximately one in five subjects. Together, these studies inspire several other important questions regarding linaclotide, including its role in the management of IBS-C relative to existing treatment options, such as lubiprostone. Greater clinical use of linaclotide will reveal whether the observed responses measured with the FDA provisional endpoint will translate into real-world experiences of improvement in IBS patients. PMID:23160292

  5. Short-term testing--are we looking at wrong endpoints?

    PubMed

    Ramel, C

    1988-01-01

    Short-term testing has been performed and interpreted on the basis of correlation between these tests and animal carcinogenicity. This empirical approach has been the only feasible one, due to a lack of knowledge of the actual genetic endpoints of relevance in carcinogenicity. However, the rapidly growing information on genetic alterations actually involved in carcinogenicity and in particular activation of oncogenes, provides facts of basic importance for the strategy of short-term testing. The presently used sets of short-term tests focus on standard genetic endpoints, mainly point mutations and chromosomal aberrations. Little attention has been paid in that connection to other endpoints, which have been shown or suspected to play an important role in carcinogenicity. These endpoints include gene amplification, transpositions, hypomethylation, polygene mutations and recombinogenic effects. Furthermore, indirect effects, for instance via radical generation and an imbalance of the nucleotide pool, may be of great significance for the carcinogenic and cocarcinogenic effects of many chemicals. Modern genetic and molecular technology has opened entirely new prospects for identifying genetic alterations in tumours and in its turn these prospects should be taken advantage of in order to build up more sophisticated batteries of assays, adapted to the genetic endpoints actually demonstrated to be involved in cancer induction. Development of new assay systems in accordance with the elucidation of genetic alterations in carcinogenicity will probably constitute one of the most important areas in genetic toxicology in the future. From a regulatory point of view the prerequisite for a development in this direction will be a flexibility of the handling of questions concerning short-term testing also at a bureaucratic level. PMID:3285184

  6. The Impact of Chemoembolization Endpoints on Survival in Hepatocellular Carcinoma Patients

    PubMed Central

    Jin, Brian; Wang, Dingxin; Lewandowski, Robert J.; Riaz, Ahsun; Ryu, Robert K.; Sato, Kent T.; Larson, Andrew C.; Salem, Riad; Omary, Reed A.

    2010-01-01

    OBJECTIVE To investigate the relationship between angiographic embolic endpoints of transarterial chemoembolization (TACE) and survival in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS This study retrospectively assessed 105 patients with surgically unresectable HCC who underwent TACE. Patients were classified according to a previously established subjective angiographic chemoembolization endpoint (SACE) scale. Only one patient was classified as SACE level 1 and thus excluded from all subsequent analysis. Survival was evaluated with Kaplan-Meier analysis. Multivariate analysis with Cox’s proportional hazard regression model was used to determine independent prognostic risk factors of survival. RESULTS Overall median survival was 21.1 months (95% confidence interval [CI], 15.9–26.4). Patients embolized to SACE levels 2 and 3 were aggregated and had a significantly higher median survival (25.6 months; 95% CI, 16.2–35.0) than patients embolized to SACE level 4 (17.1 months; 95% CI, 13.3–20.9) (p = 0.035). Multivariate analysis indicated that SACE level 4 (Hazard ratio [HR], 2.49; 95% CI, 1.41–4.42; p = 0.002), European Cooperative Oncology Group performance status > 0 (HR, 1.97; 95% CI, 1.15–3.37; p = 0.013), American Joint Committee on Cancer stage 3 or 4 (HR, 2.42; 95% CI, 1.27–4.60; p = 0.007), and Child-Pugh class B (HR, 1.94; 95% CI, 1.09–3.46; p = 0.025) were all independent negative prognostic indicators of survival. CONCLUSION Embolization to an intermediate, sub-stasis endpoint (SACE levels 2 and 3) during TACE improves survival compared to embolization to a higher, stasis endpoint (SACE level 4). Interventional oncologists should consider targeting these intermediate, sub-stasis angiographic endpoints during TACE. PMID:21427346

  7. Developmental derivation of embryonic and adult macrophages.

    PubMed

    Shepard, J L; Zon, L I

    2000-01-01

    The macrophage cell lineage continually arises from hematopoietic stem cells during embryonic, fetal, and adult life. Previous theories proposed that macrophages are the recent progeny of bone marrow-derived monocytes and that they function primarily in phagocytosis. More recently, however, observations have shown that the ontogeny of macrophages in early mouse and human embryos is different from that occurring during adult development, and that the embryonic macrophages do not follow the monocyte pathway. Fetal macrophages are thought to differentiate from yolk sac-derived primitive macrophages before the development of adult monocytes. Further support for a separate lineage of fetal macrophages has come from studies of several species, including chicken, zebrafish, Xenopus, Drosophila, and C. elegans. The presence of fetal macrophages in PU.1-null mice indicates their independence from monocyte precursors and their existence as an alternative macrophage lineage. PMID:10608497

  8. OCT guided microinjections for mouse embryonic research

    NASA Astrophysics Data System (ADS)

    Larin, Kirill V.; Syed, Saba H.; Coughlin, Andrew J.; Wang, Shang; West, Jennifer L.; Dickinson, Mary E.; Larina, Irina V.

    2013-02-01

    Optical coherence tomography (OCT) is gaining popularity as live imaging tool for embryonic research in animal models. Recently we have demonstrated that OCT can be used for live imaging of cultured early mouse embryos (E7.5-E10) as well as later stage mouse embryos in utero (E12.5 to the end of gestation). Targeted delivery of signaling molecules, drugs, and cells is a powerful approach to study normal and abnormal development, and image guidance is highly important for such manipulations. Here we demonstrate that OCT can be used to guide microinjections of gold nanoshell suspensions in live mouse embryos. This approach can potentially be used for variety of applications such as guided injections of contrast agents, signaling molecules, pharmacological agents, cell transplantation and extraction, as well as other image-guided micromanipulations. Our studies also reveal novel potential for gold nanoshells in embryonic research.

  9. Mechanically patterning the embryonic airway epithelium

    PubMed Central

    Varner, Victor D.; Gleghorn, Jason P.; Miller, Erin; Radisky, Derek C.; Nelson, Celeste M.

    2015-01-01

    Collections of cells must be patterned spatially during embryonic development to generate the intricate architectures of mature tissues. In several cases, including the formation of the branched airways of the lung, reciprocal signaling between an epithelium and its surrounding mesenchyme helps generate these spatial patterns. Several molecular signals are thought to interact via reaction-diffusion kinetics to create distinct biochemical patterns, which act as molecular precursors to actual, physical patterns of biological structure and function. Here, however, we show that purely physical mechanisms can drive spatial patterning within embryonic epithelia. Specifically, we find that a growth-induced physical instability defines the relative locations of branches within the developing murine airway epithelium in the absence of mesenchyme. The dominant wavelength of this instability determines the branching pattern and is controlled by epithelial growth rates. These data suggest that physical mechanisms can create the biological patterns that underlie tissue morphogenesis in the embryo. PMID:26170292

  10. Mechanically patterning the embryonic airway epithelium.

    PubMed

    Varner, Victor D; Gleghorn, Jason P; Miller, Erin; Radisky, Derek C; Nelson, Celeste M

    2015-07-28

    Collections of cells must be patterned spatially during embryonic development to generate the intricate architectures of mature tissues. In several cases, including the formation of the branched airways of the lung, reciprocal signaling between an epithelium and its surrounding mesenchyme helps generate these spatial patterns. Several molecular signals are thought to interact via reaction-diffusion kinetics to create distinct biochemical patterns, which act as molecular precursors to actual, physical patterns of biological structure and function. Here, however, we show that purely physical mechanisms can drive spatial patterning within embryonic epithelia. Specifically, we find that a growth-induced physical instability defines the relative locations of branches within the developing murine airway epithelium in the absence of mesenchyme. The dominant wavelength of this instability determines the branching pattern and is controlled by epithelial growth rates. These data suggest that physical mechanisms can create the biological patterns that underlie tissue morphogenesis in the embryo. PMID:26170292

  11. A trade-off between embryonic development rate and immune function of avian offspring is concealed by embryonic temperature

    USGS Publications Warehouse

    Martin, Thomas E.; Arriero, Elena; Majewska, Ania

    2011-01-01

    Long embryonic periods are assumed to reflect slower intrinsic development that are thought to trade off to allow enhanced physiological systems, such as immune function. Yet, the relatively rare studies of this trade-off in avian offspring have not found the expected trade-off. Theory and tests have not taken into account the strong extrinsic effects of temperature on embryonic periods of birds. Here, we show that length of the embryonic period did not explain variation in two measures of immune function when temperature was ignored, based on studies of 34 Passerine species in tropical Venezuela (23 species) and north temperate Arizona (11 species). Variation in immune function was explained when embryonic periods were corrected for average embryonic temperature, in order to better estimate intrinsic rates of development. Immune function of offspring trades off with intrinsic rates of embryonic development once the extrinsic effects of embryonic temperatures are taken into account.

  12. Metabolic circadian rhythms in embryonic turtles.

    PubMed

    Loudon, Fiona Kay; Spencer, Ricky-John; Strassmeyer, Alana; Harland, Karen

    2013-07-01

    Oviparous species are model organisms for investigating embryonic development of endogenous physiological circadian rhythms without the influence of maternal biorhythms. Recent studies have demonstrated that heart rates and metabolic rates of embryonic turtles are not constant or always maximal and can be altered in response to the presence of embryos at a more advanced stage of development within the nest. A first step in understanding the physiological mechanisms underpinning these responses in embryonic ectothermic organisms is to develop metabolic profiles (e.g., heart rate) at different temperatures throughout incubation. Heart beat and rhythmic patterns or changes in development may represent important signals or cues within a nest and may be vital to coordinate synchronous hatching well in advance of the final stages of incubation. We developed baseline embryonic heart-rate profiles of embryos of the short-necked Murray River turtle (Emydura macquarii) to determine the stage of embryogenesis that metabolic circadian rhythms become established, if at all. Eggs were incubated at constant temperatures (26°C and 30°C) and heart rates were monitored at 6-h intervals over 24 h every 7-11 days until hatching. Circadian heart rate rhythms were detected at the mid-gestation period and were maintained until hatching. Heart rates throughout the day varied by up to 20% over 24 h and were not related to time of day. This study demonstrated that endogenous metabolic circadian rhythms in developing embryos in turtle eggs establish earlier in embryogenesis than those documented in other vertebrate taxa during embryogenesis. Early establishment of circadian rhythms in heart rates may be critical for communication among embryos and synchrony in hatching and emergence from the nest. PMID:23652198

  13. Hedgehog Signalling in the Embryonic Mouse Thymus

    PubMed Central

    Saldaña, José Ignacio; Crompton, Tessa

    2016-01-01

    T cells develop in the thymus, which provides an essential environment for T cell fate specification, and for the differentiation of multipotent progenitor cells into major histocompatibility complex (MHC)-restricted, non-autoreactive T cells. Here we review the role of the Hedgehog signalling pathway in T cell development, thymic epithelial cell (TEC) development, and thymocyte–TEC cross-talk in the embryonic mouse thymus during the last week of gestation. PMID:27504268

  14. Isolation of Murine Embryonic Hemogenic Endothelial Cells.

    PubMed

    Fang, Jennifer S; Gritz, Emily C; Marcelo, Kathrina L; Hirschi, Karen K

    2016-01-01

    The specification of hemogenic endothelial cells from embryonic vascular endothelium occurs during brief developmental periods within distinct tissues, and is necessary for the emergence of definitive HSPC from the murine extra embryonic yolk sac, placenta, umbilical vessels, and the embryonic aorta-gonad-mesonephros (AGM) region. The transient nature and small size of this cell population renders its reproducible isolation for careful quantification and experimental applications technically difficult. We have established a fluorescence-activated cell sorting (FACS)-based protocol for simultaneous isolation of hemogenic endothelial cells and HSPC during their peak generation times in the yolk sac and AGM. We demonstrate methods for dissection of yolk sac and AGM tissues from mouse embryos, and we present optimized tissue digestion and antibody conjugation conditions for maximal cell survival prior to identification and retrieval via FACS. Representative FACS analysis plots are shown that identify the hemogenic endothelial cell and HSPC phenotypes, and describe a methylcellulose-based assay for evaluating their blood forming potential on a clonal level. PMID:27341393

  15. Gene expression analysis of the embryonic subplate

    PubMed Central

    Oeschger, Franziska M.; Wang, Wei-Zhi; Lee, Sheena; García-Moreno, Fernando; Goffinet, André M.; Arbones, Mariona; Rakic, Sonia; Molnár, Zoltán

    2015-01-01

    The subplate layer of the cerebral cortex is comprised of a heterogeneous population of cells and contains some of the earliest-generated neurons. In the embryonic brain, subplate cells contribute to the guidance and areal targeting of thalamocortical axons. At later stages, they are involved in the maturation and plasticity of the cortical circuitry and the establishment of functional modules. We aimed to further characterize the embryonic murine subplate population by establishing a gene expression profile at embryonic day 15.5 using laser capture microdissection and microarrays. The microarray identified over 300 transcripts with higher expression in the subplate compared to the cortical plate at this stage. Using quantitative RT-PCR, in situ hybridization and immunohistochemistry, we have confirmed specific expression in the E15.5 subplate for 13 selected genes which have not been previously associated with this compartment (Abca8a, Cdh10, Cdh18, Csmd3, Gabra5, Kcnt2, Ogfrl1, Pls3, Rcan2, Sv2b, Slc8a2, Unc5c and Zdhhc2). In the reeler mutant, the expression of the majority of these genes (9 out of 13) was shifted in accordance with the altered position of subplate. These genes belong to several functional groups and likely contribute to the maturation and electrophysiological properties of subplate cells and to axonal growth and guidance. PMID:21862448

  16. Mechanical signaling coordinates the embryonic heartbeat.

    PubMed

    Chiou, Kevin K; Rocks, Jason W; Chen, Christina Yingxian; Cho, Sangkyun; Merkus, Koen E; Rajaratnam, Anjali; Robison, Patrick; Tewari, Manorama; Vogel, Kenneth; Majkut, Stephanie F; Prosser, Benjamin L; Discher, Dennis E; Liu, Andrea J

    2016-08-01

    In the beating heart, cardiac myocytes (CMs) contract in a coordinated fashion, generating contractile wave fronts that propagate through the heart with each beat. Coordinating this wave front requires fast and robust signaling mechanisms between CMs. The primary signaling mechanism has long been identified as electrical: gap junctions conduct ions between CMs, triggering membrane depolarization, intracellular calcium release, and actomyosin contraction. In contrast, we propose here that, in the early embryonic heart tube, the signaling mechanism coordinating beats is mechanical rather than electrical. We present a simple biophysical model in which CMs are mechanically excitable inclusions embedded within the extracellular matrix (ECM), modeled as an elastic-fluid biphasic material. Our model predicts strong stiffness dependence in both the heartbeat velocity and strain in isolated hearts, as well as the strain for a hydrogel-cultured CM, in quantitative agreement with recent experiments. We challenge our model with experiments disrupting electrical conduction by perfusing intact adult and embryonic hearts with a gap junction blocker, β-glycyrrhetinic acid (BGA). We find this treatment causes rapid failure in adult hearts but not embryonic hearts-consistent with our hypothesis. Last, our model predicts a minimum matrix stiffness necessary to propagate a mechanically coordinated wave front. The predicted value is in accord with our stiffness measurements at the onset of beating, suggesting that mechanical signaling may initiate the very first heartbeats. PMID:27457951

  17. Human embryonic stem cells and lung regeneration

    PubMed Central

    Varanou, A; Page, C P; Minger, S L

    2008-01-01

    Human embryonic stem cells are pluripotent cells derived from the inner cell mass of preimplantation stage embryos. Their unique potential to give rise to all differentiated cell types has generated great interest in stem cell research and the potential that it may have in developmental biology, medicine and pharmacology. The main focus of stem cell research has been on cell therapy for pathological conditions with no current methods of treatment, such as neurodegenerative diseases, cardiac pathology, retinal dysfunction and lung and liver disease. The overall aim is to develop methods of application either of pure cell populations or of whole tissue parts to the diseased organ under investigation. In the field of pulmonary research, studies using human embryonic stem cells have succeeded in generating enriched cultures of type II pneumocytes in vitro. On account of their potential of indefinite proliferation in vitro, embryonic stem cells could be a source of an unlimited supply of cells available for transplantation and for use in gene therapy. Uncovering the ability to generate such cell types will expand our understanding of biological processes to such a degree that disease understanding and management could change dramatically. PMID:18724383

  18. Embryonic development of Pelteobagrus fulvidraco (Richardson, 1846)

    NASA Astrophysics Data System (ADS)

    Wang, Weimin; Abbas, Khalid; Yan, Ansheng

    2006-12-01

    For production enhancement and procedure upgrade, the developmental phases of laboratory-reared eggs of catfish Pelteobagrus fulvidraco were investigated. Twenty mature females and 10 males were collected from Dadongmen wholesale fisheries market in Wuhan City on May 8, 2003. Zygotes were stripped from mature fish after hormone-induced ovulation, fertilized, and incubated through whole embryonic development. The fertilized eggs were stocked in density of 100 eggs/L in white square tanks of 10 L. Incubation water was dechlorinated tap water with continuous aeration. The tanks were lit directly with 60 W fluorescent bulbs with a 12 light: 12 dark photoperiod. Water temperature, dissolved oxygen and pH were 29.0±0.5°C, 6.7±0.4 mg/L and 7.4±2, respectively. The results showed that the eggs of P. fulvidraco were yellow, sticky and contained much yolk. The mean diameter of fertilized eggs was 2.03 mm. At the water temperature of 29.0±0.5°C, the ontogenesis spent about 33 h after fertilization. From fertilization to hatching, the embryonic development can be divided into 30 40 phases, which varies in the emphasis and direction of development. The detailed embryonic movement was also described.

  19. Gene expression analysis of the embryonic subplate.

    PubMed

    Oeschger, Franziska M; Wang, Wei-Zhi; Lee, Sheena; García-Moreno, Fernando; Goffinet, André M; Arbonés, Maria L; Rakic, Sonja; Molnár, Zoltán

    2012-06-01

    The subplate layer of the cerebral cortex is comprised of a heterogeneous population of cells and contains some of the earliest-generated neurons. In the embryonic brain, subplate cells contribute to the guidance and areal targeting of thalamocortical axons. At later developmental stages, they are predominantly involved in the maturation and plasticity of the cortical circuitry and the establishment of functional modules. We aimed to further characterize the embryonic murine subplate population by establishing a gene expression profile at embryonic day (E) 15.5 using laser capture microdissection and microarrays. The microarray identified over 300 transcripts with higher expression in the subplate compared with the cortical plate at this stage. Using quantitative reverse transcription-polymerase chain reaction, in situ hybridization (ISH), and immunohistochemistry (IHC), we have confirmed specific expression in the E15.5 subplate for 13 selected genes, which have not been previously associated with this compartment (Abca8a, Cdh10, Cdh18, Csmd3, Gabra5, Kcnt2, Ogfrl1, Pls3, Rcan2, Sv2b, Slc8a2, Unc5c, and Zdhhc2). In the reeler mutant, the expression of the majority of these genes (9 of 13) was shifted in accordance with the altered position of subplate. These genes belong to several functional groups and likely contribute to synapse formation and axonal growth and guidance in subplate cells. PMID:21862448

  20. From teratocarcinomas to embryonic stem cells.

    PubMed Central

    Andrews, Peter W

    2002-01-01

    The recent derivation of human embryonic stem (ES) cell lines, together with results suggesting an unexpected degree of plasticity in later, seemingly more restricted, stem cells (so-called adult stem cells), have combined to focus attention on new opportunities for regenerative medicine, as well as for understanding basic aspects of embryonic development and diseases such as cancer. Many of the ideas that are now discussed have a long history and much has been underpinned by the earlier studies of teratocarcinomas, and their embryonal carcinoma (EC) stem cells, which present a malignant surrogate for the normal stem cells of the early embryo. Nevertheless, although the potential of EC and ES cells to differentiate into a wide range of tissues is now well attested, little is understood of the key regulatory mechanisms that control their differentiation. Apart from the intrinsic biological interest in elucidating these mechanisms, a clear understanding of the molecular process involved will be essential if the clinical potential of these cells is to be realized. The recent observations of stem-cell plasticity suggest that perhaps our current concepts about the operation of cell regulatory pathways are inadequate, and that new approaches for analysing complex regulatory networks will be essential. PMID:12028783

  1. Isolation of Murine Embryonic Hemogenic Endothelial Cells

    PubMed Central

    Marcelo, Kathrina L.; Hirschi, Karen K.

    2016-01-01

    The specification of hemogenic endothelial cells from embryonic vascular endothelium occurs during brief developmental periods within distinct tissues, and is necessary for the emergence of definitive HSPC from the murine extra embryonic yolk sac, placenta, umbilical vessels, and the embryonic aorta-gonad-mesonephros (AGM) region. The transient nature and small size of this cell population renders its reproducible isolation for careful quantification and experimental applications technically difficult. We have established a fluorescence-activated cell sorting (FACS)-based protocol for simultaneous isolation of hemogenic endothelial cells and HSPC during their peak generation times in the yolk sac and AGM. We demonstrate methods for dissection of yolk sac and AGM tissues from mouse embryos, and we present optimized tissue digestion and antibody conjugation conditions for maximal cell survival prior to identification and retrieval via FACS. Representative FACS analysis plots are shown that identify the hemogenic endothelial cell and HSPC phenotypes, and describe a methylcellulose-based assay for evaluating their blood forming potential on a clonal level. PMID:27341393

  2. Combined functional and anatomical diagnostic endpoints for assessing arteriovenous fistula dysfunction

    PubMed Central

    Rajabi-Jaghargh, Ehsan; Banerjee, Rupak K

    2015-01-01

    Failure of arteriovenous fistulas (AVF) to mature and thrombosis in matured fistulas have been the major causes of morbidity and mortality in hemodialysis patients. Stenosis, which occurs due to adverse remodeling in AVFs, is one of the major underlying factors under both scenarios. Early diagnosis of a stenosis in an AVF can provide an opportunity to intervene in a timely manner for either assisting the maturation process or avoiding the thrombosis. The goal of surveillance strategies was to supplement the clinical evaluation (i.e., physical examination) of the AVF for better and earlier diagnosis of a developing stenosis. Surveillance strategies were mainly based on measurement of functional hemodynamic endpoints, including blood flow (Qa) to the vascular access and venous access pressure (VAP). As the changes in arterial pressure (MAP) affects the level of VAP, the ratio of VAP to MAP (VAPR = VAP/MAP) was used for diagnosis. A Qa < 400-500 mL/min or a VAPR > 0.55 is considered sign of significant stenosis, which requires immediate intervention. However, due to the complex nature of AVFs, the surveillance strategies have failed to consistently detect stenosis under different scenarios. VAPR has been primarily developed to detect outflow stenosis in arteriovenous grafts, and it hasn’t been successful in accurate diagnosis of outflow lesions in AVFs. Similarly, AVFs can maintain relatively high blood flow despite the presence of a significant outflow stenosis and thus, Qa has been found to be a better predictor of only inflow lesions. Similar shortcomings have been reported in the detection of functional severity of coronary stenosis using diagnostic endpoints that were based on either flow or pressure. This limitation has been associated with the fact that both pressure and flow change in the presence of a stenosis and thus, hemodynamic diagnostic endpoints that employ only one of these parameters are inherently prone to inaccuracies. Recent attempts have

  3. Dopamine Receptors in Human Embryonic Stem Cell Neurodifferentiation

    PubMed Central

    Belinsky, Glenn S.; Sirois, Carissa L.; Rich, Matthew T.; Short, Shaina M.; Moore, Anna R.; Gilbert, Sarah E.

    2013-01-01

    We tested whether dopaminergic drugs can improve the protocol for in vitro differentiation of H9 human embryonic stem cells (hESCs) into dopaminergic neurons. The expression of 5 dopamine (DA) receptor subtypes (mRNA and protein) was analyzed at each protocol stage (1, undifferentiated hESCs; 2, embryoid bodies [EBs]; 3, neuroepithelial rosettes; 4, expanding neuroepithelium; and 5, differentiating neurons) and compared to human fetal brain (gestational week 17–19). D2-like DA receptors (D2, D3, and D4) predominate over the D1-like receptors (D1 and D5) during derivation of neurons from hESCs. D1 was the receptor subtype with the lowest representation in each protocol stage (Stages 1–5). D1/D5-agonist SKF38393 and D2/D3/D4-agonist quinpirole (either alone or combined) evoked Ca2+ responses, indicating functional receptors in hESCs. To identify when receptor activation causes a striking effect on hESC neurodifferentiation, and what ligands and endpoints are most interesting, we varied the timing, duration, and drug in the culture media. Dopaminergic agonists or antagonists were administered either early (Stages 1–3) or late (Stages 4–5). Early DA exposure resulted in more neuroepithelial colonies, more neuronal clusters, and more TH+ clusters. The D1/D5 antagonist SKF83566 had a strong effect on EB morphology and the expression of midbrain markers. Late exposure to DA resulted in a modest increase in TH+ neuron clusters (∼75%). The increase caused by DA did not occur in the presence of dibutyryl cAMP (dbcAMP), suggesting that DA acts through the cAMP pathway. However, a D2-antagonist (L741) decreased TH+ cluster counts. Electrophysiological parameters of the postmitotic neurons were not significantly affected by late DA treatment (Stages 4–5). The mRNA of mature neurons (VGLUT1 and GAD1) and the midbrain markers (GIRK2, LMX1A, and MSX1) were lower in hESCs treated by DA or a D2-antagonist. When hESCs were neurodifferentiated on PA6 stromal cells, DA also

  4. The influence of water quality on the embryonic survivorship of the Oregon spotted frog (Rana pretiosa) in British Columbia, Canada.

    PubMed

    McKibbin, René; Dushenko, William T; vanAggelen, Graham; Bishop, Christine A

    2008-05-20

    In Canada, the Oregon spotted frog (Rana pretiosa) is a critically endangered species with only three known populations and an estimated breeding population of less than 400 located in isolated sites in the extreme south-west corner of British Columbia. Floating Nitex cages were used to assess embryonic survivorship in two populations of Oregon spotted frogs from 2002-2005. One population, near Aldergrove, BC experienced declines in population size while the other population, at Maria Slough, increased during the period 1997-2001. During embryo development, we measured trace metals, nutrients and physical parameters in the water at each site. These were used to test the hypothesis that water quality parameters were correlated with embryonic survivorship. During the study period in the declining population at Aldergrove R. pretiosa bred at two distinct sub sites (A and B) located 500 m apart within the wetland. Mean embryonic survivorship varied from 9% to 36% at sub site A and from 78% to 88% at sub site B whereas in the population in Maria Slough, the mean embryonic survivorship varied from 77% to 84%. Sulphate was the only water chemistry variable that differed significantly between the two study sites and was the highest at Maria Slough. A weak significant positive correlation was found between chloride and embryonic survivorship and conductivity and embryonic survivorship. A multiple regression model found conductivity was the only significant variable. We concluded that natural water chemistry conditions of low chloride and consequently low conductivity may be contributing to low embryonic survivorship in the population of R. pretiosa at MD Aldergrove, BC. PMID:18336868

  5. The calorimetric spectrum of the electron-capture decay of 163Ho. The spectral endpoint region

    NASA Astrophysics Data System (ADS)

    De Rújula, A.; Lusignoli, M.

    2016-05-01

    The electron-neutrino mass (or masses and mixing angles) may be directly measurable in weak electron-capture decays. The favoured experimental technique is "calorimetric". The optimal nuclide is 163Ho, and several experiments (ECHo, HOLMES and NuMECS) are currently studying its decay. The most relevant range of the calorimetric-energy spectrum extends for the last few hundred eV below its endpoint. It has not yet been well measured. We explore the theory, mainly in the cited range, of electron capture in 163Ho decay. A so far neglected process turns out to be most relevant: electron-capture accompanied by the shake-off of a second electron. Our two main conclusions are very encouraging: the counting rate close to the endpoint may be more than an order of magnitude larger than previously expected; the "pile-up" problem may be significantly reduced.

  6. Development of drugs for celiac disease: review of endpoints for Phase 2 and 3 trials

    PubMed Central

    Gottlieb, Klaus; Dawson, Jill; Hussain, Fez; Murray, Joseph A.

    2015-01-01

    Celiac disease is a lifelong disorder for which there is currently only one known, effective treatment: a gluten-free diet. New treatment approaches have recently emerged; several drugs are in Phase 2 trials and results appear promising; however, discussion around regulatory endpoints is in its infancy. We will briefly discuss the drugs that are under development and then shift our attention to potential trial endpoints, such as patient-reported outcomes, histology, serology, gene expression analysis and other tests. We will outline the differing requirements for proof-of-concept Phase 2 trials and Phase 3 registration trials, with a particular emphasis on current thinking in regulatory agencies. We conclude our paper with recommendations and a glossary of regulatory terms, to enable readers who are less familiar with regulatory language to take maximum advantage of this review. PMID:25725041

  7. Emerging treatments in management of prostate cancer: biomarker validation and endpoints for immunotherapy clinical trial design

    PubMed Central

    Slovin, Susan F

    2014-01-01

    The rapidly emerging field of immunotherapy and the development of novel immunologic agents that have been approved in melanoma and successfully studied in lung cancer, kidney cancer, and prostate cancer have mandated that there be uniformity in clinical trial analysis beyond conventional survival endpoints and imaging. This includes some measure of determining whether the immunologic target is hit and how the treatment has impacted on the immune system in toto. While melanoma is leading the field towards these ends, there is some doubt that not all of the recent successes with immune therapies, for example, checkpoint inhibitors, will be effective for every cancer, and that the toxicities may also be different depending on the malignancy. This review serves to elucidate the current issues facing clinical investigators who perform immunologic trials targeted at patients with prostate cancer and discusses the challenges in assessing the right immunologic endpoints to demonstrate biologic/immunologic targeting leading to clinical benefit.

  8. Development of drugs for celiac disease: review of endpoints for Phase 2 and 3 trials.

    PubMed

    Gottlieb, Klaus; Dawson, Jill; Hussain, Fez; Murray, Joseph A

    2015-05-01

    Celiac disease is a lifelong disorder for which there is currently only one known, effective treatment: a gluten-free diet. New treatment approaches have recently emerged; several drugs are in Phase 2 trials and results appear promising; however, discussion around regulatory endpoints is in its infancy. We will briefly discuss the drugs that are under development and then shift our attention to potential trial endpoints, such as patient-reported outcomes, histology, serology, gene expression analysis and other tests. We will outline the differing requirements for proof-of-concept Phase 2 trials and Phase 3 registration trials, with a particular emphasis on current thinking in regulatory agencies. We conclude our paper with recommendations and a glossary of regulatory terms, to enable readers who are less familiar with regulatory language to take maximum advantage of this review. PMID:25725041

  9. Mind the gap: Concerns using endpoints from endocrine screening assays in risk assessment.

    PubMed

    Wheeler, James R; Weltje, Lennart; Green, Richard M

    2014-08-01

    Endocrine screening assays not only provide mechanistic information on the potential of a substance to interact with the endocrine system, but also data potentially relevant for risk assessment. However, these screening assays have a number of limitations that should be considered before the direct use of such data for risk assessment purposes. This paper discusses the limitations that should be considered for both human and environmental risk assessment. A proposal is made to provide an objective and transparent process in order to consider which endpoint(s) might be incorporated into a risk assessment, and when more definitive studies may be of value. The proposal is complemented with an easy-to-follow flowchart to aid industry scientists and regulators when evaluating the relevance of these data. Such an approach is necessary to ensure the appropriate use of screening data to further our understanding of the eco/toxicological profile of substances undergoing screening. PMID:24887212

  10. Roberge-Weiss endpoint in N{sub f}=2 QCD

    SciTech Connect

    Bonati, Claudio; Cossu, Guido; D'Elia, Massimo; Sanfilippo, Francesco

    2011-03-01

    We present the results of extensive simulations regarding the critical behavior at the endpoint of the Roberge-Weiss transition for N{sub f}=2 QCD. We confirm early evidence, presented in Ref. [M. D'Elia and F. Sanfilippo, Phys. Rev. D 80, 111501(R) (2009).], according to which the Roberge-Weiss endpoint is first order in the limit of large or small quark masses, and second order for intermediate masses. A systematic study of the transition strength as a function of the quark mass in the first order regions, permits us to estimate the tricritical values of the quark mass separating the second order region from the first order ones.

  11. Analysis of Cardiomyocyte Development using Immunofluorescence in Embryonic Mouse Heart

    PubMed Central

    Wilsbacher, Lisa D.; Coughlin, Shaun R.

    2015-01-01

    During heart development, the generation of myocardial-specific structural and functional units including sarcomeres, contractile myofibrils, intercalated discs, and costameres requires the coordinated assembly of multiple components in time and space. Disruption in assembly of these components leads to developmental heart defects. Immunofluorescent staining techniques are used commonly in cultured cardiomyocytes to probe myofibril maturation, but this ex vivo approach is limited by the extent to which myocytes will fully differentiate in culture, lack of normal in vivo mechanical inputs, and absence of endocardial cues. Application of immunofluorescence techniques to the study of developing mouse heart is desirable but more technically challenging, and methods often lack sufficient sensitivity and resolution to visualize sarcomeres in the early stages of heart development. Here, we describe a robust and reproducible method to co-immunostain multiple proteins or to co-visualize a fluorescent protein with immunofluorescent staining in the embryonic mouse heart and use this method to analyze developing myofibrils, intercalated discs, and costameres. This method can be further applied to assess cardiomyocyte structural changes caused by mutations that lead to developmental heart defects. PMID:25866997

  12. Stochastic Cell Fate Progression in Embryonic Stem Cells

    NASA Astrophysics Data System (ADS)

    Zou, Ling-Nan; Doyle, Adele; Jang, Sumin; Ramanathan, Sharad

    2013-03-01

    Studies on the directed differentiation of embryonic stem (ES) cells suggest that some early developmental decisions may be stochastic in nature. To identify the sources of this stochasticity, we analyzed the heterogeneous expression of key transcription factors in single ES cells as they adopt distinct germ layer fates. We find that under sufficiently stringent signaling conditions, the choice of lineage is unambiguous. ES cells flow into differentiated fates via diverging paths, defined by sequences of transitional states that exhibit characteristic co-expression of multiple transcription factors. These transitional states have distinct responses to morphogenic stimuli; by sequential exposure to multiple signaling conditions, ES cells are steered towards specific fates. However, the rate at which cells travel down a developmental path is stochastic: cells exposed to the same signaling condition for the same amount of time can populate different states along the same path. The heterogeneity of cell states seen in our experiments therefore does not reflect the stochastic selection of germ layer fates, but the stochastic rate of progression along a chosen developmental path. Supported in part by the Jane Coffin Childs Fund

  13. Mouse submandibular gland morphogenesis: a paradigm for embryonic signal processing.

    PubMed

    Melnick, M; Jaskoll, T

    2000-01-01

    Signal processing is the sine qua non of embryogenesis. At its core, any single signal transduction pathway may be understood as classic Information Theory, adapted as an open system such that, because of networking, the "receiver" is presented with more information than was initially signaled by the "source". Over 40 years ago, Waddington presented his "Epigenetic Landscape" as a metaphor for the hierarchical nature of embryogenesis. Mathematically, Waddington's landscape may be modeled as a neural net. The "black box" of the neural net is an interacting network of signal transduction pathways (using hormones, growth factors, cytokines, neurotransmitters, and others) which inform the Boolean logic gates. An emerging theme in developmental biology is that defined sets of epigenetic circuits are used in multiple places, at multiple times, for similar and sometimes different purposes during organogenesis. As we show here, submandibular gland embryonic and fetal development is a splendid paradigm of these epigenetic circuits and their phenotypic outcomes, such as branching and lumen formation. PMID:12002815

  14. Kinetic titration with differential thermometric determination of the end-point.

    PubMed

    Sajó, I

    1968-06-01

    A method has been described for the determination of concentrations below 10(-4)M by applying catalytic reactions and using thermometric end-point determination. A reference solution, identical with the sample solution except for catalyst, is titrated with catalyst solution until the rates of reaction become the same, as shown by a null deflection on a galvanometer connected via bridge circuits to two opposed thermistors placed in the solutions. PMID:18960338

  15. Improvement of end-point detection in the non-aqueous titration of sulphacetamide sodium.

    PubMed

    Soliman, S A; Belal, S; Bediar, M

    1984-04-01

    The sluggish end-point in the non-aqueous titration of sulphacetamide sodium in glacial acetic acid can be improved by addition of acetic anhydride to the titration medium, and selective determination of sulphacetamide sodium in presence of phenylephrine hydrochloride in eye drops then becomes possible. A mixture of sulphacetamide sodium and the antihistamine drug phenyltoloxamine dihydrogen citrate can also be analysed. PMID:18963589

  16. Clinical usefulness and relevance of intermediate endpoints for cytotoxic neoadjuvant therapy.

    PubMed

    Fontanella, Caterina; Loibl, Sibylle; von Minckwitz, Gunter

    2015-11-01

    Intermediate endpoints are surrogate markers of treatment efficacy assessed earlier than the true outcome of interest. Tumor response after systemic neoadjuvant therapy is considered a suitable intermediate endpoint, especially for specific breast cancer subtypes. Response can be evaluated either after only 1 cycle of treatment by clinical evaluation or at the end of the planned neoadjuvant treatment by histomorphologic examination of all surgically removed tissues from the breast and regional nodes. Although several meta-analyses showed a lower risk of death among patients who attain a pathologic complete response (pCR) compared with patients with residual tumor in breast and/or lymph nodes after neoadjuvant therapy, a statistically significant linkage between increased pCR rate by a specific treatment and improvement of survival by the same treatment has not been demonstrated yet. Therefore, formal surrogacy of pCR is not established. Moreover, the better definition of pCR is still an open issue: a large pooled analysis demonstrated that patients who attained ypT0 ypN0 (no invasive or non-invasive residual cancer in breast and nodes) experienced longer DFS (p < 0.001) compared with patients who attained ypTis ypN0 (no invasive residual in breast and nodes irrespective of residual non-invasive disease). Nevertheless, the Food and Drug Administration (FDA) recently allowed using pCR as a surrogate endpoint for accelerated approval process. Several meta-analyses demonstrated the greatest prognostic value of pCR in more aggressive breast cancer subtypes (i.e. triple-negative, HER2-positive, or high grade breast cancer). Usefulness of an earlier intermediate endpoints was prospectively demonstrated in the GeparTrio trial in which patients showing an early response achieved 4-times more frequently a pCR than those without early response. PMID:26279131

  17. Feasibility of Using Distal Endpoints for In-room PET Range Verification of Proton Therapy

    PubMed Central

    Grogg, Kira; Zhu, Xuping; Min, Chul Hee; Winey, Brian; Bortfeld, Thomas; Paganetti, Harald; Shih, Helen A.; El Fakhri, Georges

    2013-01-01

    In an effort to verify the dose delivery in proton therapy, Positron Emission Tomography (PET) scans have been employed to measure the distribution of β+ radioactivity produced from nuclear reactions of the protons with native nuclei. Because the dose and PET distributions are difficult to compare directly, the range verification is currently carried out by comparing measured and Monte Carlo (MC) simulation predicted PET distributions. In order to reduce the reliance on MC, simulated PET (simPET) and dose distal endpoints were compared to explore the feasibility of using distal endpoints for in-room PET range verification. MC simulations were generated for six head and neck patients with corrections for radiological decay, biological washout, and PET resolution. One-dimensional profiles of the dose and simPET were examined along the direction of the beam and covering the cross section of the beam. The chosen endpoints of the simPET (x-intercept of the linear fit to the distal falloff) and planned dose (20–50% of maximum dose) correspond to where most of the protons are below the threshold energy for the nuclear reactions. The difference in endpoint range between the distal surfaces of the dose and MC-PET were compared and the spread of range differences were assessed. Among the six patients, the mean difference between MC-PET and dose depth was found to be −1.6 mm to +0.5 mm between patients, with a standard deviation of 1.1 to 4.0 mm across the individual beams. In clinical practice, regions with deviations beyond the safety margin need to be examined more closely and can potentially lead to adjustments to the treatment plan. PMID:24464031

  18. Energy metabolism and biotransformation as endpoints to pre-screen hepatotoxicity using a liver spheroid model

    SciTech Connect

    Xu Jinsheng . E-mail: jinsheng.xu@uwe.ac.uk; Purcell, Wendy M.

    2006-10-15

    The current study investigated liver spheroid culture as an in vitro model to evaluate the endpoints relevant to the status of energy metabolism and biotransformation after exposure to test toxicants. Mature rat liver spheroids were exposed to diclofenac, galactosamine, isoniazid, paracetamol, m-dinitrobenzene (m-DNB) and 3-nitroaniline (3-NA) for 24 h. Pyruvate uptake, galactose biotransformation, lactate release and glucose secretion were evaluated after exposure. The results showed that pyruvate uptake and lactate release by mature liver spheroids in culture were maintained at a relatively stable level. These endpoints, together with glucose secretion and galactose biotransformation, were related to and could reflect the status of energy metabolism and biotransformation in hepatocytes. After exposure, all of the test agents significantly reduced glucose secretion, which was shown to be the most sensitive endpoint of those evaluated. Diclofenac, isoniazid, paracetamol and galactosamine reduced lactate release (P < 0.01), but m-DNB increased lactate release (P < 0.01). Diclofenac, isoniazid and paracetamol also reduced pyruvate uptake (P < 0.01), while galactosamine had little discernible effect. Diclofenac, galactosamine, paracetamol and m-DNB also reduced galactose biotransformation (P < 0.01), by contrast, isoniazid did not. The metabolite of m-DNB, 3-NA, which served as a negative control, did not cause significant changes in lactate release, pyruvate uptake or galactose biotransformation. It is concluded that pyruvate uptake, galactose biotransformation, lactate release and glucose secretion can be used as endpoints for evaluating the status of energy metabolism and biotransformation after exposure to test agents using the liver spheroid model to pre-screen hepatotoxicity.

  19. Muscle Synergies Heavily Influence the Neural Control of Arm Endpoint Stiffness and Energy Consumption

    PubMed Central

    Inouye, Joshua M.; Valero-Cuevas, Francisco J.

    2016-01-01

    Much debate has arisen from research on muscle synergies with respect to both limb impedance control and energy consumption. Studies of limb impedance control in the context of reaching movements and postural tasks have produced divergent findings, and this study explores whether the use of synergies by the central nervous system (CNS) can resolve these findings and also provide insights on mechanisms of energy consumption. In this study, we phrase these debates at the conceptual level of interactions between neural degrees of freedom and tasks constraints. This allows us to examine the ability of experimentally-observed synergies—correlated muscle activations—to control both energy consumption and the stiffness component of limb endpoint impedance. In our nominal 6-muscle planar arm model, muscle synergies and the desired size, shape, and orientation of endpoint stiffness ellipses, are expressed as linear constraints that define the set of feasible muscle activation patterns. Quadratic programming allows us to predict whether and how energy consumption can be minimized throughout the workspace of the limb given those linear constraints. We show that the presence of synergies drastically decreases the ability of the CNS to vary the properties of the endpoint stiffness and can even preclude the ability to minimize energy. Furthermore, the capacity to minimize energy consumption—when available—can be greatly affected by arm posture. Our computational approach helps reconcile divergent findings and conclusions about task-specific regulation of endpoint stiffness and energy consumption in the context of synergies. But more generally, these results provide further evidence that the benefits and disadvantages of muscle synergies go hand-in-hand with the structure of feasible muscle activation patterns afforded by the mechanics of the limb and task constraints. These insights will help design experiments to elucidate the interplay between synergies and the

  20. Quantitative 4D Transcatheter Intraarterial Perfusion MR Imaging as a Method to Standardize Angiographic Chemoembolization Endpoints

    PubMed Central

    Jin, Brian; Wang, Dingxin; Lewandowski, Robert J.; Ryu, Robert K.; Sato, Kent T.; Larson, Andrew C.; Salem, Riad; Omary, Reed A.

    2011-01-01

    PURPOSE We aimed to test the hypothesis that subjective angiographic endpoints during transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) exhibit consistency and correlate with objective intraprocedural reductions in tumor perfusion as determined by quantitative four dimensional (4D) transcatheter intraarterial perfusion (TRIP) magnetic resonance (MR) imaging. MATERIALS AND METHODS This prospective study was approved by the institutional review board. Eighteen consecutive patients underwent TACE in a combined MR/interventional radiology (MR-IR) suite. Three board-certified interventional radiologists independently graded the angiographic endpoint of each procedure based on a previously described subjective angiographic chemoembolization endpoint (SACE) scale. A consensus SACE rating was established for each patient. Patients underwent quantitative 4D TRIP-MR imaging immediately before and after TACE, from which mean whole tumor perfusion (Fρ) was calculated. Consistency of SACE ratings between observers was evaluated using the intraclass correlation coefficient (ICC). The relationship between SACE ratings and intraprocedural TRIP-MR imaging perfusion changes was evaluated using Spearman’s rank correlation coefficient. RESULTS The SACE rating scale demonstrated very good consistency among all observers (ICC = 0.80). The consensus SACE rating was significantly correlated with both absolute (r = 0.54, P = 0.022) and percent (r = 0.85, P < 0.001) intraprocedural perfusion reduction. CONCLUSION The SACE rating scale demonstrates very good consistency between raters, and significantly correlates with objectively measured intraprocedural perfusion reductions during TACE. These results support the use of the SACE scale as a standardized alternative method to quantitative 4D TRIP-MR imaging to classify patients based on embolic endpoints of TACE. PMID:22021520

  1. Establishing Good Practices for Exposure–Response Analysis of Clinical Endpoints in Drug Development

    PubMed Central

    Overgaard, RV; Ingwersen, SH; Tornøe, CW

    2015-01-01

    This tutorial aims at promoting good practices for exposure–response (E-R) analyses of clinical endpoints in drug development. The focus is on practical aspects of E-R analyses to assist modeling scientists with a process of performing such analyses in a consistent manner across individuals and projects and tailored to typical clinical drug development decisions. This includes general considerations for planning, conducting, and visualizing E-R analyses, and how these are linked to key questions. PMID:26535157

  2. Polysilicon planarization and plug recess etching in a decoupled plasma source chamber using two endpoint techniques

    NASA Astrophysics Data System (ADS)

    Kaplita, George A.; Schmitz, Stefan; Ranade, Rajiv; Mathad, Gangadhara S.

    1999-09-01

    The planarization and recessing of polysilicon to form a plug are processes of increasing importance in silicon IC fabrication. While this technology has been developed and applied to DRAM technology using Trench Storage Capacitors, the need for such processes in other IC applications (i.e. polysilicon studs) has increased. Both planarization and recess processes usually have stringent requirements on etch rate, recess uniformity, and selectivity to underlying films. Additionally, both processes generally must be isotropic, yet must not expand any seams that might be present in the polysilicon fill. These processes should also be insensitive to changes in exposed silicon area (pattern factor) on the wafer. A SF6 plasma process in a polysilicon DPS (Decoupled Plasma Source) reactor has demonstrated the capability of achieving the above process requirements for both planarization and recess etch. The SF6 process in the decoupled plasma source reactor exhibited less sensitivity to pattern factor than in other types of reactors. Control of these planarization and recess processes requires two endpoint systems to work sequentially in the same recipe: one for monitoring the endpoint when blanket polysilicon (100% Si loading) is being planarized and one for monitoring the recess depth while the plug is being recessed (less than 10% Si loading). The planarization process employs an optical emission endpoint system (OES). An interferometric endpoint system (IEP), capable of monitoring lateral interference, is used for determining the recess depth. The ability of using either or both systems is required to make these plug processes manufacturable. Measuring the recess depth resulting from the recess process can be difficult, costly and time- consuming. An Atomic Force Microscope (AFM) can greatly alleviate these problems and can serve as a critical tool in the development of recess processes.

  3. Comprehensive Review on the Surrogate Endpoints of Efficacy Proposed or Hypothesized in the Scientific Community Today.

    PubMed

    von Minckwitz, Gunter; Fontanella, Caterina

    2015-05-01

    An intermediate endpoint is a surrogate marker of treatment efficacy assessed earlier than the true outcome of interest. A suitable intermediate endpoint in neoadjuvant trials of specific breast cancer subtypes is pathological complete response (pCR) rate, defined as no invasive (+/-noninvasive) residual cancer in breast and nodes at surgery. On the basis of available evidence, Food and Drug Administration the US allowed to use of pCR as a surrogate endpoint for accelerated approval process. However, surrogacy to long-term outcome remains an unresolved issue. Literature data provide indications that triple-negative, HER2-positive, and high-grade hormone receptor-positive breast cancer subtypes achieved the highest pCR rate; the prognostic impact of pCR on survival is established only for these aggressive subtypes. In the German experience, early response after two to four cycles of neoadjuvant treatment strongly correlated with both pCR rate and long-term outcome. Therefore, early response may be considered a predictive marker for pCR and used for driving clinical trial design. PMID:26063882

  4. Sensitivity Enhancement of RF Plasma Etch Endpoint Detection With K-means Cluster Analysis

    NASA Astrophysics Data System (ADS)

    Lee, Honyoung; Jang, Haegyu; Lee, Hak-Seung; Chae, Heeyeop

    2015-09-01

    Plasma etching process is the core process in semiconductor fabrication, and the etching endpoint detection is one of the essential FDC (Fault Detection and Classification) for yield management and mass production. In general, Optical emission spectrocopy (OES) has been used to detect endpoint because OES can be a non-invasive and real-time plasma monitoring tool. In OES, the trend of a few sensitive wavelengths is traced. However, in case of small-open area etch endpoint detection (ex. contact etch), it is at the boundary of the detection limit because of weak signal intensities of reaction reactants and products. Furthemore, the various materials covering the wafer such as photoresist, dielectric materials, and metals make the analysis of OES signals complicated. In this study, full spectra of optical emission signals were collected and the data were analyzed by a data-mining approach, modified K-means cluster analysis. The K-means cluster analysis is modified suitably to analyze a thousand of wavelength variables from OES. This technique can improve the sensitivity of EPD for small area oxide layer etching processes: about 1.0% oxide area. This technique is expected to be applied to various plasma monitoring applications including fault detections as well as EPD. Plasma Etch, EPD, K-means Cluster Analysis.

  5. End-point impedance measurements across dominant and nondominant hands and robotic assistance with directional damping.

    PubMed

    Erden, Mustafa Suphi; Billard, Aude

    2015-06-01

    The goal of this paper is to perform end-point impedance measurements across dominant and nondominant hands while doing airbrush painting and to use the results for developing a robotic assistance scheme. We study airbrush painting because it resembles in many ways manual welding, a standard industrial task. The experiments are performed with the 7 degrees of freedom KUKA lightweight robot arm. The robot is controlled in admittance using a force sensor attached at the end-point, so as to act as a free-mass and be passively guided by the human. For impedance measurements, a set of nine subjects perform 12 repetitions of airbrush painting, drawing a straight-line on a cartoon horizontally placed on a table, while passively moving the airbrush mounted on the robot's end-point. We measure hand impedance during the painting task by generating sudden and brief external forces with the robot. The results show that on average the dominant hand displays larger impedance than the nondominant in the directions perpendicular to the painting line. We find the most significant difference in the damping values in these directions. Based on this observation, we develop a "directional damping" scheme for robotic assistance and conduct a pilot study with 12 subjects to contrast airbrush painting with and without robotic assistance. Results show significant improvement in precision with both dominant and nondominant hands when using robotic assistance. PMID:25148680

  6. Resummation of large endpoint corrections to color-octet J/{psi} photoproduction

    SciTech Connect

    Fleming, Sean; Leibovich, Adam K.; Mehen, Thomas

    2006-12-01

    An unresolved problem in J/{psi} phenomenology is a systematic understanding of the differential photoproduction cross section, d{sigma}/dz[{gamma}+p{yields}J/{psi}+X], where z=E{sub {psi}}/E{sub {gamma}} in the proton rest frame. In the nonrelativistic QCD (NRQCD) factorization formalism, fixed-order perturbative calculations of color-octet mechanisms suffer from large perturbative and nonperturbative corrections that grow rapidly in the endpoint region, z{yields}1. In this paper, NRQCD and soft collinear effective theory are combined to resum these large corrections to the color-octet photoproduction cross section. We derive a factorization theorem for the endpoint differential cross section involving the parton distribution function and the color-octet J/{psi} shape functions. A one-loop matching calculation explicitly confirms our factorization theorem at next-to-leading order. Large perturbative corrections are resummed using the renormalization group. The calculation of the color-octet contribution to d{sigma}/dz is in qualitative agreement with data. Quantitative tests of the universality of color-octet matrix elements require improved knowledge of shape functions entering these calculations as well as resummation of the color-singlet contribution which accounts for much of the total cross section and also peaks near the endpoint.

  7. Resummation of Large Endpoint Corrections to Color-Octet J/psi Photoproduction

    SciTech Connect

    Sean Fleming; Adam K. Leibovich; Thomas Mehen

    2006-07-27

    An unresolved problem in J/{psi} phenomenology is a systematic understanding of the differential photoproduction cross section, d{sigma}/dz [{gamma} + p {yields} J/{psi} + X], where z = E{sub {psi}}/E{sub {gamma}} in the proton rest frame. In the non-relativistic QCD (NRQCD) factorization formalism, fixed-order perturbative calculations of color-octet mechanisms suffer from large perturbative and nonperturbative corrections that grow rapidly in the endpoint region, z {yields} 1. In this paper, NRQCD and soft collinear effective theory are combined to resum these large corrections to the color-octet photoproduction cross section. We derive a factorization theorem for the endpoint differential cross section involving the parton distribution function and the color-octet J/{psi} shape functions. A one loop matching calculation explicitly confirms our factorization theorem at next-to-leading order. Large perturbative corrections are resummed using the renormalization group. The calculation of the color-octet contribution to d{sigma}/dz is in qualitative agreement with data. Quantitative tests of the universality of color-octet matrix elements require improved knowledge of shape functions entering these calculations as well as resummation of the color-singlet contribution which accounts for much of the total cross section and also peaks near the endpoint.

  8. Meeting patient expectations in migraine treatment: what are the key endpoints?

    PubMed

    Antonaci, Fabio; Sances, Grazia; Guaschino, Elena; De Cillis, Ilaria; Bono, Giorgio; Nappi, Giuseppe

    2008-08-01

    Clinical outcomes of migraine treatment are generally based on two major endpoints: acute pain resolution and effects on quality of life (QOL). Resolution of acute pain can be evaluated in a number of ways, each increasingly challenging to achieve; pain relief, pain freedom at 2 h, sustained pain-freedom, and SPF plus no adverse events (SNAE, the most challenging). QOL questionnaires help assess the burden of migraine and identify optimal treatments. Pain resolution and improved QOL form the basis of the ultimate target-meeting patient expectations, to achieve patient satisfaction. To achieve this, it is crucial to choose appropriate endpoints that reflect realistic treatment goals for individual patients. Moreover, SNAE can help discriminate between triptans, with almotriptan having the highest SNAE score. Kaplan-Meier plots are also relevant when evaluating migraine treatments. The use of symptomatic medication may lead to the paradoxical development of medication-overuse headache. In general practice, patients should use simple tools for pain measurement (e.g. headache diary) and a QOL questionnaire. A composite endpoint of pain resolution and QOL restoration would constitute a step forward in migraine management. PMID:18607535

  9. The Genetic and Epigenetic Journey of Embryonic Stem Cells into Mature Neural Cells

    PubMed Central

    Olynik, Brendan M.; Rastegar, Mojgan

    2012-01-01

    Epigenetic changes occur throughout life from embryonic development into adulthood. This results in the timely expression of developmentally important genes, determining the morphology and identity of different cell types and tissues within the body. Epigenetics regulate gene expression and cellular morphology through multiple mechanisms without alteration in the underlying DNA sequences. Different epigenetic mechanisms include chromatin condensation, post-translational modification of histone proteins, DNA cytosine marks, and the activity of non-coding RNA molecules. Epigenetics play key roles in development, stem cell differentiation, and have high impact in human disease. In this review, we will discuss our current knowledge about these epigenetic mechanisms, with a focus on histone and DNA marks. We will then talk about the genetics and epigenetics of embryonic stem cell self-renewal and differentiation into neural stem cells, and further into specific neuronal cell types. PMID:22629283

  10. Directed Differentiation of Embryonic Stem Cells Using a Bead-Based Combinatorial Screening Method

    PubMed Central

    Tarunina, Marina; Hernandez, Diana; Johnson, Christopher J.; Rybtsov, Stanislav; Ramathas, Vidya; Jeyakumar, Mylvaganam; Watson, Thomas; Hook, Lilian; Medvinsky, Alexander; Mason, Chris; Choo, Yen

    2014-01-01

    We have developed a rapid, bead-based combinatorial screening method to determine optimal combinations of variables that direct stem cell differentiation to produce known or novel cell types having pre-determined characteristics. Here we describe three experiments comprising stepwise exposure of mouse or human embryonic cells to 10,000 combinations of serum-free differentiation media, through which we discovered multiple novel, efficient and robust protocols to generate a number of specific hematopoietic and neural lineages. We further demonstrate that the technology can be used to optimize existing protocols in order to substitute costly growth factors with bioactive small molecules and/or increase cell yield, and to identify in vitro conditions for the production of rare developmental intermediates such as an embryonic lymphoid progenitor cell that has not previously been reported. PMID:25251366

  11. Clinical trial design principles and endpoint definitions for transcatheter mitral valve repair and replacement: part 2: endpoint definitions: A consensus document from the Mitral Valve Academic Research Consortium.

    PubMed

    Stone, Gregg W; Adams, David H; Abraham, William T; Kappetein, Arie Pieter; Généreux, Philippe; Vranckx, Pascal; Mehran, Roxana; Kuck, Karl-Heinz; Leon, Martin B; Piazza, Nicolo; Head, Stuart J; Filippatos, Gerasimos; Vahanian, Alec S

    2015-08-01

    Mitral regurgitation (MR) is one of the most prevalent valve disorders and has numerous aetiologies, including primary (organic) MR, due to underlying degenerative/structural mitral valve (MV) pathology, and secondary (functional) MR, which is principally caused by global or regional left ventricular remodelling and/or severe left atrial dilation. Diagnosis and optimal management of MR requires integration of valve disease and heart failure specialists, MV cardiac surgeons, interventional cardiologists with expertise in structural heart disease, and imaging experts. The introduction of trans- catheter MV therapies has highlighted the need for a consensus approach to pragmatic clinical trial design and uniform endpoint definitions to evaluate outcomes in patients with MR. The Mitral Valve Academic Research Consortium is a collaboration between leading academic research organizations and physician-scientists specializing in MV disease from the United States and Europe. Three in-person meetings were held in Virginia and New York during which 44 heart failure, valve, and imaging experts, MV surgeons and interventional cardiologists, clinical trial specialists and statisticians, and representatives from the U.S. Food and Drug Administration considered all aspects of MV pathophysiology, prognosis, and therapies, culminating in a 2-part document describing consensus recommendations for clinical trial design (Part 1) and endpoint definitions (Part 2) to guide evaluation of transcatheter and surgical therapies for MR. The adoption of these recommendations will afford robustness and consistency in the comparative effectiveness evaluation of new devices and approaches to treat MR. These principles may be useful for regulatory assessment of new transcatheter MV devices, as well as for monitoring local and regional outcomes to guide quality improvement initiatives. PMID:26170468

  12. Transcriptomics-based identification of developmental toxicants through their interference with cardiomyocyte differentiation of embryonic stem cells

    SciTech Connect

    Dartel, Dorien A.M. van; Pennings, Jeroen L.A.; Schooten, Frederik J. van; Piersma, Aldert H.

    2010-03-15

    The embryonic stem cell test (EST) predicts developmental toxicity based on the inhibition of cardiomyocyte differentiation of embryonic stem cells (ESC). The subjective endpoint, the long culture duration together with the undefined applicability domain and related predictivity need further improvement to facilitate implementation of the EST into regulatory strategies. These aspects may be improved by studying gene expression changes in the ESC differentiation cultures and their modulation by compound exposure using transcriptomics. Here, we tested the developmental toxicants monobutyl phthalate and 6-aminonicotinamide. ESC were allowed to differentiated, and cardiomyocyte differentiation was assessed after 10 days of culture. RNA of solvent controls was collected after 0, 24, 48, 72 and 96 h of exposure, and RNA of developmental-toxicant-exposed cultures was collected after 24 and 96 h. Samples were hybridized to DNA microarrays, and 1355 genes were found differentially expressed among the unexposed experimental groups. These regulated genes were involved in differentiation-related processes, and Principal Component Analysis (PCA) based on these genes showed that the unexposed experimental groups appeared in chronological order in the PCA, which can therefore be regarded as a continuous representation of the differentiation track. The developmental-toxicant-exposed cultures appeared to deviate significantly from this differentiation track, which confirms the compound-modulating effects on the differentiation process. The incorporation of transcriptomics in the EST is expected to provide a more informative and improved endpoint in the EST as compared with morphology, allowing early detection of differentiation modulation. Furthermore, this approach may improve the definition of the applicability domain and predictivity of the EST.

  13. Role of patient-reported outcomes and other efficacy endpoints in the drug approval process in Europe (2008-2012).

    PubMed

    Bansal, Dipika; Bhagat, Anil; Schifano, Fabrizio; Gudala, Kapil

    2015-12-01

    The present study aimed at systematically reviewing the role and extent of patient-reported outcomes (PROs) usage within the package of scientific evidence considered for marketing authorization (MA). All regulatory information published by the European Medicines Agency (EMA) for products authorized between January 2008 and December 2012 and appearing in the European Public Assessment Report (EPAR) database was examined for efficacy endpoints. The endpoints here considered included: PROs, clinician reported outcomes (CROs), and laboratory reported outcomes (LROs). LROs were the most frequently reported endpoints. Out of the 180 products here selected, 99 (55%), 67 (37%), and 30 (17%), respectively, used LROs, CROs and PROs as primary endpoints (PEs). PROs as any endpoints were used in 82 (46%) products. Out of these, PROs were documented as PE in 30 (37%), with 27 (33%) products having used PROs both as primary and non-PEs. PRO usage was most frequently identified with nervous system and antineoplastic agents. During the study period, the use of all the three types of endpoints appeared to be static. Both the regulatory bodies and the industry should ensure complete and clear reporting of all endpoints used, including PROs, to improve transparency. PMID:26031612

  14. An opportunity to refocus on the 'humane' in experimental endpoints: moving beyond Directive 2010/63/EU.

    PubMed

    Ashall, Vanessa; Millar, Kate

    2013-09-01

    Humane endpoints are a core refinement concept in animal experimentation. This paper identifies an urgent requirement for individuals and institutions to refocus on humane endpoints as part of the transposition of Directive 2010/63/EU into the national laws of the Member States, and to go beyond their legal construction when setting new guidance or applying humane endpoints in practice. It will be argued that requirements for humane endpoints within the Directive appear not to promote recent advances in best practice, but seem reliant on a narrow and potentially outdated definition of the term. We describe progress that has been made in encouraging change in the construction and application of humane endpoints, and suggest that Directive 2010/63/EU does not sufficiently acknowledge the conceptual complexity of this refinement strategy. For example, a useful development representing recent consensual views of best practice has been proposed by an EU consortium (in 2012). A complex approach to humane endpoints may place additional demands on institutions and raise challenges that would, unfortunately, not need to be overcome in order to remain within the Directive's current requirements regarding humane endpoints. We argue that there is now a need for a practical tool to help structure appropriate ethical reflection during research planning and experimentation, in order to facilitate best practice in the application of this important refinement concept. PMID:24168135

  15. Relationship between Intrauterine Bacterial Infection and Early Embryonic Developmental Arrest

    PubMed Central

    Yan, Shao-Fei; Liu, Xin-Yan; Cheng, Yun-Fei; Li, Zhi-Yi; Ou, Jie; Wang, Wei; Li, Feng-Qin

    2016-01-01

    Background: Early embryonic developmental arrest is the most commonly understudied adverse outcome of pregnancy. The relevance of intrauterine infection to spontaneous embryonic death is rarely studied and remains unclear. This study aimed to investigate the relationship between intrauterine bacterial infection and early embryonic developmental arrest. Methods: Embryonic chorion tissue and uterine swabs for bacterial detection were obtained from 33 patients who underwent artificial abortion (control group) and from 45 patients who displayed early embryonic developmental arrest (trial group). Results: Intrauterine bacterial infection was discovered in both groups. The infection rate was 24.44% (11/45) in the early embryonic developmental arrest group and 9.09% (3/33) in the artificial abortion group. Classification analysis revealed that the highest detection rate for Micrococcus luteus in the early embryonic developmental arrest group was 13.33% (6/45), and none was detected in the artificial abortion group. M. luteus infection was significantly different between the groups (P < 0.05 as shown by Fisher's exact test). In addition, no correlation was found between intrauterine bacterial infection and history of early embryonic developmental arrest. Conclusions: M. luteus infection is related to early embryonic developmental arrest and might be one of its causative factors. PMID:27270541

  16. Embryonic myogenesis pathways in muscle regeneration.

    PubMed

    Zhao, Po; Hoffman, Eric P

    2004-02-01

    Embryonic myogenesis involves the staged induction of myogenic regulatory factors and positional cues that dictate cell determination, proliferation, and differentiation into adult muscle. Muscle is able to regenerate after damage, and muscle regeneration is generally thought to recapitulate myogenesis during embryogenesis. There has been considerable progress in the delineation of myogenesis pathways during embryogenesis, but it is not known whether the same signaling pathways are relevant to muscle regeneration in adults. Here, we defined the subset of embryogenesis pathways induced in muscle regeneration using a 27 time-point in vivo muscle regeneration series. The embryonic Wnt (Wnt1, 3a, 7a, 11), Shh pathway, and the BMP (BMP2, 4, 7) pathway were not induced during muscle regeneration. Moreover, antagonists of Wnt signaling, sFRP1, sFRP2, and sFRP4 (secreted frizzled-related proteins) were significantly up-regulated, suggesting active inhibition of the Wnt pathway. The pro-differentiation FGFR4 pathway was transiently expressed at day 3, commensurate with expression of MyoD, Myogenin, Myf5, and Pax7. Protein verification studies showed fibroblast growth factor receptor 4 (FGFR4) protein to be strongly expressed in differentiating myoblasts and newly formed myotubes. We present evidence that FGF6 is likely the key ligand for FGFR4 during muscle regeneration, and further suggest that FGF6 is released from necrotic myofibers where it is then sequestered by basal laminae. We also confirmed activation of Notch1 in the regenerating muscle. Finally, known MyoD coactivators (MEF2A, p/CIP, TCF12) and repressors (Twist, Id2) were strongly induced at appropriate time points. Taken together, our results suggest that embryonic positional signals (Wnt, Shh, and BMP) are not induced in postnatal muscle regeneration, whereas cell-autonomous factors (Pax7, MRFs, FGFR4) involving muscle precursor proliferation and differentiation are recapitulated by muscle regeneration. PMID

  17. MULTIPLE-ENDPOINT MUTAGENESIS WITH CHINESE HAMSTER OVARY (CHO) CELLS: EVALUATION WITH EIGHT CARCINOGENIC AND NON-CARCINOGENIC COMPOUNDS

    EPA Science Inventory

    Using Chinese hamster ovary (CHO) cells in culture, the authors have defined an assay, CHO/HGPRT, to quantify mutagen-induced cytotoxicity and mutations at the hypoxanthine-guanine phosphoribosyltransferase (hgprt) locus. This assay permits elucidation of the structure-activity r...

  18. The use of multiple endpoints to assess cellular responses to environmental contaminants in the interstitial marine ciliate Euplotes crassus.

    PubMed

    Gomiero, A; Sforzini, S; Dagnino, A; Nasci, C; Viarengo, A

    2012-06-15

    This paper presents the results of investigations on the suitability of Euplotes crassus, an interstitial marine ciliate, to be used as model organism in ecotoxicology and thereafter to evaluate the toxicity of estuarine and coastal sediments upon laboratory exposure. Nowadays, anthropogenic activities have resulted in accumulation of metals and organic pollutants in the environment as well as in the food chain hence leading to serious ecological and human health problems. This may pose a risk to benthic and epibenthic organisms and it is crucial to discover toxicity tests that will identify adverse effects of sediment-associated chemicals on benthic organisms. Due to their nature as a eukaryotic cell/organism and their position in the food web, ciliated protozoa are suitable models for evaluating the effects of pollution on aquatic communities. Lethal and sublethal effects of exposure to inorganic and organic pollutants were tested on the cell mortality, replication rate, lysosomal membrane stability and endocytosis rate of E. crassus. Increasing nominal concentrations of individual and mixtures of mercury, copper, and benzo(a)pyrene were investigated in this study as they might be bioavailable in naturally occurring polluted sites. A significant decrease in the mean replication rate (p<0.05) was found after 24h exposures to m/μM concentrations of all tested pollutants. At the same time, significant decreases of lysosomal membrane stability (p<0.05) were observed for Cu (5 μM), Hg (10 nM), and B(a)P (200 nM). Among the entire suite of tests, endocytosis rate test demonstrated the highest sensitivity. Exposures to binary mixtures of all studied pollutants were performed showing both inorganic-organic and inorganic-inorganic additive and/or antagonist effects. Moreover, medium salinity was also varied to mimic estuarine-like environmental conditions linking biological response to ionic strengths. Under these conditions significant increases of both endocytosis rate and lysosomal membrane stability were observed and related to the increment of some Hg- and Cu-related toxic complexes. The studied biomarkers were always able to discriminate between the effects of organic and inorganic pollutants. Together with the short time and simplicity of the test procedures, results obtained in this study indicate that E. crassus is a promising and convenient bioindicator for evaluating the toxicity of different environmental matrixes like pore water, sediments and wastewaters--polluted by metals and organic pollutants. PMID:22459342

  19. Nonhomologous DNA end joining and chromosome aberrations in human embryonic lung fibroblasts treated with environmental pollutants.

    PubMed

    Rossner, Pavel; Rossnerova, Andrea; Beskid, Olena; Tabashidze, Nana; Libalova, Helena; Uhlirova, Katerina; Topinka, Jan; Sram, Radim J

    2014-01-01

    In order to evaluate the ability of a representative polycyclic aromatic hydrocarbon (PAH) and PAH-containing complex mixtures to induce double strand DNA breaks (DSBs) and repair of damaged DNA in human embryonic lung fibroblasts (HEL12469 cells), we investigated the effect of benzo[a]pyrene (B[a]P) and extractable organic matter (EOM) from ambient air particles <2.5μm (PM2.5) on nonhomologous DNA end joining (NHEJ) and induction of stable chromosome aberrations (CAs). PM2.5 was collected in winter and summer 2011 in two Czech cities differing in levels and sources of air pollutants. The cells were treated for 24h with the following concentrations of tested chemicals: B[a]P: 1μM, 10μM, 25μM; EOMs: 1μg/ml, 10μg/ml, 25μg/ml. We tested several endpoints representing key steps leading from DSBs to the formation of CAs including histone H2AX phosphorylation, levels of proteins Ku70, Ku80 and XRCC4 participating in NHEJ, in vitro ligation activity of nuclear extracts of the HEL12469 cells and the frequency of stable CAs assessed by whole chromosome painting of chromosomes 1, 2, 4, 5, 7 and 17 using fluorescence in situ hybridization. Our results show that 25μM of B[a]P and most of the tested doses of EOMs induced DSBs as indicated by H2AX phosphorylation. DNA damage was accompanied by induction of XRCC4 expression and an increased frequency of CAs. Translocations most frequently affected chromosome 7. We observed only a weak induction of Ku70/80 expression as well as ligation activity of nuclear extracts. In summary, our data suggest the induction of DSBs and NHEJ after treatment of human embryonic lung fibroblasts with B[a]P and complex mixtures containing PAHs. PMID:24694657

  20. Comparison of an automated pattern analysis machine vision time-lapse system with traditional endpoint measurements in the analysis of cell growth and cytotoxicity.

    PubMed

    Toimela, Tarja; Tähti, Hanna; Ylikomi, Timo

    2008-07-01

    Machine vision is an application of computer vision. It both collects visual information and interprets the images. Although the machine obviously does not 'see' in the same sense that humans do, it is possible to acquire visual information and to create programmes to identify relevant image features in an effective and consistent manner. Machine vision is widely applied in industrial automation, but here we describe how we have used it to monitor and interpret data from cell cultures. The machine vision system used (Cell-IQ) consisted of an inbuilt atmosphere-controlled incubator, where cell culture plates were placed during the test. Artificial intelligence (AI) software, which uses machine vision technology, took care of the follow-up analysis of cellular morphological changes. Basic endpoint and staining methods to evaluate the condition of the cells, were conducted in parallel to the machine vision analysis. The results showed that the automated system for pattern analysis of morphological changes yielded comparable results to those obtained by conventional methods. The inbuilt software analysis offers a promising way of evaluating cell growth and various cell phases. The continuous follow-up and label-free analysis, as well as the possibility of measuring multiple parameters simultaneously from the same cell population, were major advantages of this system, as compared to conventional endpoint measurement methodology. PMID:18662095

  1. Generation and application of mammalian haploid embryonic stem cells.

    PubMed

    Bai, M; Wu, Y; Li, J

    2016-09-01

    Haploid cells contain one set of chromosomes and are amenable for genetic analyses. In mammals, haploidy exists only in gametes. An intriguing question is whether haploid cells can be derived from gametes. Recently, by application of haploid cell enrichment using fluorescence-activated cell sorting, stable haploid embryonic stem cells (haESCs) have been successfully derived from oocyte-derived parthenogenetic and sperm-derived androgenetic embryos from several species. Whilst both parthenogenetic and androgenetic (AG)-haESCs enable whole-genome genetic screening at the cellular level, such as screening of drug resistance or disease-related genes, AG-haESCs, after intracytoplasmic injection into oocytes, can also be used to produce alive semi-cloned mice. Nevertheless, one major drawback associated with wild-type AG-haESCs is the very low birth rate of healthy semi-cloned mice. Of interest, after inhibiting the expression of two paternally imprinted genes (H19 and Gtl2) in AG-haESCs by removal of their differentially DNA methylated regions, double-knockout AG-haESCs can efficiently and stably support the generation of healthy semi-cloned pups. Importantly, double-knockout AG-haESCs are feasible for multiple genetic manipulations, followed by efficient generation of semi-cloned mice carrying multiple genetic traits; thus they could be used to validate candidate loci that have been identified in genome-wide association studies of multigenic diseases by generation of mouse models carrying multiple alterations. Of note, by combining a CRISPR-Cas9 library and double-knockout AG-haESCs, semi-cloned mice carrying different mutant genes can be efficiently generated in one step, enabling functional mutagenic screening in mice. HaESCs, therefore, provide a powerful tool for genetic analyses in mammals at both the cellular and organismal levels. PMID:27138065

  2. Chromosomal Aneuploidies and Early Embryonic Developmental Arrest

    PubMed Central

    Maurer, Maria; Ebner, Thomas; Puchner, Manuela; Mayer, Richard Bernhard; Shebl, Omar; Oppelt, Peter; Duba, Hans-Christoph

    2015-01-01

    Background Selecting the best embryo for transfer, with the highest chance of achieving a vital pregnancy, is a major goal in current in vitro fertilization (IVF) technology. The high rate of embryonic developmental arrest during IVF treatment is one of the limitations in achieving this goal. Chromosomal abnormalities are possibly linked with chromosomal arrest and selection against abnormal fertilization products. The objective of this study was to evaluate the frequency and type of chromosomal abnormalities in preimplantation embryos with developmental arrest. Materials and Methods This cohort study included blastomeres of embryos with early developmental arrest that were biopsied and analyzed by fluorescence in-situ hybridization (FISH) with probes for chromosomes 13, 16, 18, 21 and 22. Forty-five couples undergoing IVF treatment were included, and 119 arrested embryos were biopsied. All probes were obtained from the Kinderwunsch Zentrum, Linz, Austria, between August 2009 and August 2011. Results Of these embryos, 31.6% were normal for all chromosomes tested, and 68.4% were abnormal. Eleven embryos were uniformly aneuploid, 20 were polyploid, 3 were haploid, 11 displayed mosaicism and 22 embryos exhibited chaotic chromosomal complement. Conclusion Nearly 70% of arrested embryos exhibit chromosomal errors, making chromosomal abnormalities a major cause of embryonic arrest and may be a further explanation for the high developmental failure rates during culture of the embryos in the IVF setting. PMID:26644858

  3. Mechanical signaling coordinates the embryonic heart

    NASA Astrophysics Data System (ADS)

    Chiou, Kevin; Rocks, Jason; Prosser, Benjamin; Discher, Dennis; Liu, Andrea

    The heart is an active material which relies on robust signaling mechanisms between cells in order to produce well-timed, coordinated beats. Heart tissue is composed primarily of active heart muscle cells (cardiomyocytes) embedded in a passive extracellular matrix. During a heartbeat, cardiomyocyte contractions are coordinated across the heart to form a wavefront that propagates through the tissue to pump blood. In the adult heart, this contractile wave is coordinated via intercellular electrical signaling.Here we present theoretical and experimental evidence for mechanical coordination of embryonic heartbeats. We model cardiomyocytes as mechanically excitable Eshelby inclusions embedded in an overdamped elastic-fluid biphasic medium. For physiological parameters, this model replicates recent experimental measurements of the contractile wavefront which are not captured by electrical signaling models. We additionally challenge our model by pharmacologically blocking gap junctions, inhibiting electrical signaling between myocytes. We find that while adult hearts stop beating almost immediately after gap junctions are blocked, embryonic hearts continue beating even at significantly higher concentrations, providing strong support for a mechanical signaling mechanism.

  4. Proteome analysis of chick embryonic cerebrospinal fluid.

    PubMed

    Parada, Carolina; Gato, Angel; Aparicio, Mariano; Bueno, David

    2006-01-01

    During early stages of embryo development, the brain cavity is filled with embryonic cerebrospinal fluid (E-CSF), a complex fluid containing different protein fractions that contributes to the regulation of the survival, proliferation and neurogenesis of the neuroectodermal stem cells. Using 2-DE, protein sequencing and database searches, we identified and analyzed the proteome of the E-CSF from chick embryos (Gallus gallus). We identified 26 different gene products, including proteins related to the extracellular matrix, proteins associated with the regulation of osmotic pressure and metal transport, proteins related to cell survival, MAP kinase activators, proteins involved in the transport of retinol and vitamin D, antioxidant and antimicrobial proteins, intracellular proteins and some unknown proteins. Most of these gene products are involved in the regulation of developmental processes during embryogenesis in systems other than E-CSF. Interestingly, 14 of them are also present in adult human CSF proteome, and it has been reported that they are altered in the CSF of patients suffering neurodegenerative diseases and/or neurological disorders. Understanding these molecules and the mechanisms they control during embryonic neurogenesis is a key contribution to the general understanding of CNS development, and may also contribute to greater knowledge of these human diseases. PMID:16287170

  5. Multiple-input, multiple-output system identification for characterization of limb stiffness dynamics.

    PubMed

    Perreault, E J; Kirsch, R F; Acosta, A M

    1999-05-01

    This study presents time-domain and frequency-domain, multiple-input, multiple-output (MIMO) linear system identification techniques that can be used to estimate the dynamic endpoint stiffness of a multijoint limb. The stiffness of a joint or limb arises from a number of physiological mechanisms and is thought to play a fundamental role in the control of posture and movement. Estimates of endpoint stiffness can therefore be used to characterize its modulation during physiological tasks and may provide insight into how the nervous system normally controls motor behavior. Previous MIMO stiffness estimates have focused upon the static stiffness components only or assumed simple parametric models with elastic, viscous, and inertial components. The method presented here captures the full stiffness dynamics during a relatively short experimental trial while assuming only that the system is linear for small perturbations. Simulation studies were performed to investigate the performance of this approach under typical experimental conditions. It was found that a linear MIMO description of endpoint stiffness dynamics was sufficient to describe the displacement responses to small stochastic force perturbations. Distortion of these linear estimates by nonlinear centripetal and Coriolis forces was virtually undetectable for these perturbations. The system identification techniques were also found to be robust in the presence of significant output measurement noise and input coupling. These results indicate that the approach described here will allow the estimation of endpoint stiffness dynamics in an experimentally efficient manner with minimal assumptions about the specific form of these properties. PMID:10365425

  6. What is Normal? A Characterization of the Values and Variabilty in Reproductive Endpoints of the Fathead Minnow, Pimephales promelas

    EPA Science Inventory

    Jensen et al. investigated aspects of the normal reproductive biology of the fathead minnow (FHM, P. promelas), and subsequent studies have generated a large amount of additional reproductive data for endpoints such as plasma steroid hormone and vitellogenin concentrations, spa...

  7. Use of ITS to develop a methodology for determining mammographic X-ray spectrum end-point energies

    SciTech Connect

    Napolitano, M.E.; Hertel, N.E.; Trueblood, J.H.

    1995-12-31

    Quality control of mammography is very important. The kilovoltage across the X-ray tube affects low-level contrast and image quality, which are important in detecting masses and calcifications in mammography. Creating an easily reproducible method to determine the end-point energy, or peak kilovoltage, of the X-ray beam is important to provide consistent, high standards for all mammography units. Currently, the end-point energy is routinely measured at all mammography sites, but different measuring devices and methods are used. Use of a phantom, or test object, which records the results on film for centralized analysis of the end-point energy would be useful. A phantom with foils of different elements and various thicknesses embedded in acrylic is proposed for use with the film as a detector to determine the end-point energy.

  8. Alternative Endpoints and Approaches for the Remediation of Contaminated Groundwater at Complex Sites - 13426

    SciTech Connect

    Deeb, Rula A.; Hawley, Elisabeth L.

    2013-07-01

    The goal of United States (U.S.) Department of Energy's (DOE)'s environmental remediation programs is to restore groundwater to beneficial use, similar to many other Federal and state environmental cleanup programs. Based on past experience, groundwater remediation to pre-contamination conditions (i.e., drinking water standards or non-detectable concentrations) can be successfully achieved at many sites. At a subset of the most complex sites, however, complete restoration is not likely achievable within the next 50 to 100 years using today's technology. This presentation describes several approaches used at complex sites in the face of these technical challenges. Many complex sites adopted a long-term management approach, whereby contamination was contained within a specified area using active or passive remediation techniques. Consistent with the requirements of their respective environmental cleanup programs, several complex sites selected land use restrictions and used risk management approaches to accordingly adopt alternative cleanup goals (alternative endpoints). Several sites used long-term management designations and approaches in conjunction with the alternative endpoints. Examples include various state designations for groundwater management zones, technical impracticability (TI) waivers or greater risk waivers at Superfund sites, and the use of Monitored Natural Attenuation (MNA) or other passive long-term management approaches over long time frames. This presentation will focus on findings, statistics, and case studies from a recently-completed report for the Department of Defense's Environmental Security Technology Certification Program (ESTCP) (Project ER-0832) on alternative endpoints and approaches for groundwater remediation at complex sites under a variety of Federal and state cleanup programs. The primary objective of the project was to provide environmental managers and regulators with tools, metrics, and information needed to evaluate

  9. Nanog: a new recruit to the embryonic stem cell orchestra.

    PubMed

    Cavaleri, Fatima; Schöler, Hans R

    2003-05-30

    In this issue of Cell, and add a new transcriptional operating system to the known Oct4 and Stat3 systems required for early embryonal stem cell potency and self-renewal. Nanog, a homeobox transcription factor, plays a crucial role in the second embryonic cell fate specification following formation of the blastocyst. PMID:12787492

  10. Embryonic transcriptome analysis of the Caribbean fruit fly, Anastrepha suspensa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The embryonic transcriptome of the Caribbean fruit fly, Anastrepha suspensa, was sequenced by 454 pyrosequencing in an effort to isolate embryonic promoters and genes involved in programmed cell death. A cDNA library was constructed from total RNA pooled from various time points in embryogenesis usi...

  11. Regulatory aspects of Phase 3 endpoints for new inhaled antibiotics for cystic fibrosis patients with chronic Pseudomonas aeruginosa infections.

    PubMed

    Montgomery, Alan Bruce; Abuan, Tammy; Yeager, Melissa A

    2012-08-01

    Available regulatory guidelines for developing inhaled anti-infective therapies offer general advice, but specific guidance often provides conflicting and outdated advice in regard to clinical trial design. For instance, the availability of two approved drugs makes the conduct of placebo-controlled trials longer than 28 days problematic. Comparator drugs require use per the product label, making comparator trials difficult to blind as taste, foaming, regimen, device, and delivery time differences are present. Currently, there is no consensus on the most appropriate endpoints for evaluation of aerosolized antimicrobials. FEV(1) is a surrogate endpoint that it is a predictor of mortality--it is standardized, reproducible, noninvasive, simple, and inexpensive to perform but small statistically significant changes may not be clinically important. FEV(1) improvement also has a ceiling effect in patients with mild lung function impairment and spirometry cannot be reliably done in patients under the age of 6 years. A patient-reported outcome is a promising clinical endpoint. However, there is not currently an accepted tool that can be used as a primary endpoint for the FDA or the EMA, although the latter recognizes the CFQ-R as a validated secondary endpoint and the FDA grandfathered acceptance of the CFQ-R respiratory domain in the pivotal aztreonam for inhalation study. Exacerbations are an important clinical endpoint that reflects morbidity and are a major driver of cost of care, but they occur infrequently and a standardized definition has not been reached. Furthermore, an exacerbation endpoint may fail even with an otherwise effective antibiotic therapy. Regulatory authorities will have a difficult time approving any new inhaled antibiotic based on one clinical endpoint alone. PMID:22857271

  12. Determination of Endpoint Energy and Bremsstrahlung Spectra for High-Energy Radiation-Therapy Beams

    NASA Astrophysics Data System (ADS)

    Landry, Danny Joe

    Few attempts have been made to experimentally determine thick-target bremsstrahlung spectra of megavoltage therapy beams. For spectral studies using the Compton scattering technique, sodium iodine (NaI) detectors with relatively poor energy resolution have been used. Other experimental techniques for determining spectra are generally not suited for a clinical environment with the inherent time and space constraints. To gather more spectral information than previously obtained in the region near the endpoint energy, the use of a high-resolution intrinsic-germanium (Ge) detector was proposed. A response function matrix was determined from experimentally obtained pulse height distributions on the multichannel analyzer. The distributions were for nine various monoenergetic sources between 280 adn 1525 keV. The response function was used to convert the measured pulse height distributions to photon flux spectra using an iterative approximation technique with a computer. Photon flux spectra from the Sagittaire Linear Accelerator were obtained at average-electron endpoint energies of 15, 20, and 25 MeV. Two spectra were measured at the 25 MeV setting; one spectrum was measured along the central axis and one spectrum at 4(DEGREES) off axis. Photon spectra were also obtained for a Van de Graaff generator at the nominal endpoint energies of 2.2, 2.35, and 2.5 MeV. The results for both the linac and the Van de Graaff generator were compared with theoretical spectra and previously measured spectra where available. Also, photon spectra from a Theratron-80 (('60)Co) unit were determined for three field sizes and for a 10 x 10 cm. field with a lucite tray or a 45(DEGREES) wedge in the beam. The resulting spectra were compared to previously measured ('60)Co spectra.

  13. The Oral HIV/AIDS Research Alliance: updated case definitions of oral disease endpoints.

    PubMed

    Shiboski, C H; Patton, L L; Webster-Cyriaque, J Y; Greenspan, D; Traboulsi, R S; Ghannoum, M; Jurevic, R; Phelan, J A; Reznik, D; Greenspan, J S

    2009-07-01

    The Oral HIV/AIDS Research Alliance (OHARA) is part of the AIDS Clinical Trials Group (ACTG), the largest HIV clinical trials organization in the world. Its main objective is to investigate oral complications associated with HIV/AIDS as the epidemic is evolving, in particular, the effects of antiretrovirals on oral mucosal lesion development and associated fungal and viral pathogens. The OHARA infrastructure comprises: the Epidemiologic Research Unit (at the University of California San Francisco), the Medical Mycology Unit (at Case Western Reserve University) and the Virology/Specimen Banking Unit (at the University of North Carolina). The team includes dentists, physicians, virologists, mycologists, immunologists, epidemiologists and statisticians. Observational studies and clinical trials are being implemented at ACTG-affiliated sites in the US and resource-poor countries. Many studies have shared end-points, which include oral diseases known to be associated with HIV/AIDS measured by trained and calibrated ACTG study nurses. In preparation for future protocols, we have updated existing diagnostic criteria of the oral manifestations of HIV published in 1992 and 1993. The proposed case definitions are designed to be used in large-scale epidemiologic studies and clinical trials, in both US and resource-poor settings, where diagnoses may be made by non-dental healthcare providers. The objective of this article is to present updated case definitions for HIV-related oral diseases that will be used to measure standardized clinical end-points in OHARA studies, and that can be used by any investigator outside of OHARA/ACTG conducting clinical research that pertains to these end-points. PMID:19594839

  14. Early analysis of surrogate endpoints for metastatic melanoma in immune checkpoint inhibitor trials.

    PubMed

    Petrelli, Fausto; Coinu, Andrea; Cabiddu, Mary; Borgonovo, Karen; Ghilardi, Mara; Lonati, Veronica; Barni, Sandro

    2016-06-01

    Recent major phase III trials led to the approval of immune checkpoint inhibitors (ipilimumab, pembrolizumab, and nivolumab) in metastatic malignant melanoma (MM). We aim to assess whether median progression-free survival, and 1 and 2-year overall survival (OS) rates are reliable surrogate endpoints for median OS through a meta-analysis of published trials involving immunotherapy. A systematic literature search in PubMed, EMBASE, Web of Science, and SCOPUS of published phase II to III trials with immunotherapy as the treatment for MM was conducted. Adjusted weighted linear regression was used to calculate Pearson correlations (R) between surrogates and median OS, and between treatment effects on surrogates and median OS. A total of 13 studies involving 3373 patients with MM were identified. The correlation of progression-free survival with OS was not significant (R = 0.45, P = .11). Conversely, the correlation between 1-year OS and median OS was very strong (R = 0.93, 95% confidence interval [CI] 0.84-0.96, P < .00001), as was the correlation between 2-year OS and OS (R = 0.79, 95% CI 0.51-0.91, P = .0001). The correlation between the treatment effects on 1-year OS and OS was also significant (R = -0.86, 95% CI -0.3 to 0.97, P = .01). Similar results were obtained for 2-year OS. According to the available study data, 1-year OS rate could be regarded as a potential surrogate for median OS in novel immunotherapy trials of metastatic MM. Waiting for ongoing studies (e.g., pembrolizumab), we suggest that this intermediate endpoint could be considered as a potential primary endpoint in future clinical trials. PMID:27368007

  15. Early analysis of surrogate endpoints for metastatic melanoma in immune checkpoint inhibitor trials

    PubMed Central

    Petrelli, Fausto; Coinu, Andrea; Cabiddu, Mary; Borgonovo, Karen; Ghilardi, Mara; Lonati, Veronica; Barni, Sandro

    2016-01-01

    Abstract Recent major phase III trials led to the approval of immune checkpoint inhibitors (ipilimumab, pembrolizumab, and nivolumab) in metastatic malignant melanoma (MM). We aim to assess whether median progression-free survival, and 1 and 2-year overall survival (OS) rates are reliable surrogate endpoints for median OS through a meta-analysis of published trials involving immunotherapy. A systematic literature search in PubMed, EMBASE, Web of Science, and SCOPUS of published phase II to III trials with immunotherapy as the treatment for MM was conducted. Adjusted weighted linear regression was used to calculate Pearson correlations (R) between surrogates and median OS, and between treatment effects on surrogates and median OS. A total of 13 studies involving 3373 patients with MM were identified. The correlation of progression-free survival with OS was not significant (R = 0.45, P = .11). Conversely, the correlation between 1-year OS and median OS was very strong (R = 0.93, 95% confidence interval [CI] 0.84–0.96, P < .00001), as was the correlation between 2-year OS and OS (R = 0.79, 95% CI 0.51–0.91, P = .0001). The correlation between the treatment effects on 1-year OS and OS was also significant (R = −0.86, 95% CI −0.3 to 0.97, P = .01). Similar results were obtained for 2-year OS. According to the available study data, 1-year OS rate could be regarded as a potential surrogate for median OS in novel immunotherapy trials of metastatic MM. Waiting for ongoing studies (e.g., pembrolizumab), we suggest that this intermediate endpoint could be considered as a potential primary endpoint in future clinical trials. PMID:27368007

  16. Integration of Mutation and Chromosomal Damage Endpoints into 28-Day Repeat Dose Toxicology Studies

    PubMed Central

    Dertinger, Stephen D.; Phonethepswath, Souk; Franklin, Dean; Weller, Pamela; Torous, Dorothea K.; Bryce, Steven M.; Avlasevich, Svetlana; Bemis, Jeffrey C.; Hyrien, Ollivier; Palis, James; MacGregor, James T.

    2010-01-01

    Two endpoints of genetic toxicity, mutation at the X-linked Pig-a gene and chromosomal damage in the form of micronucleated reticulocytes (MN-RETs), were evaluated in blood samples obtained from 28-day repeat-dosing studies typical of those employed in toxicity evaluations. Male Wistar Han rats were treated at 24-h intervals on days 1 through 28 with one of five prototypical genotoxicants: N-ethyl-N-nitrosourea, 7,12-dimethyl-12-benz[a]anthracene, 4-nitroquinoline-1-oxide (4NQO), benzo(a)pyrene, and N-methyl-N-nitrosourea. Flow cytometric scoring of CD59-negative erythrocytes (indicative of glycosylphosphatidylinositol anchor deficiency and hence Pig-a mutation) was performed using blood specimens obtained on days −1, 15, 29, and 56. Blood specimens collected on days 4 and 29 were evaluated for MN-RET frequency using flow cytometry–based MicroFlow Kits. With the exception of 4NQO, each chemical induced significant increases in the frequency of MN-RETs on days 4 and 29. All five agents increased the frequency of mutant phenotype (CD59 negative) reticulocytes (RETs) and erythrocytes. Mutation responses in RETs occurred earlier than in erythrocytes and tended to peak, or nearly peak, at day 29. In contrast, the mutant phenotype erythrocyte responses were modest on day 29 and required additional time to reach their maximal value. The observed kinetics were expected based on the known turnover of RETs and erythrocytes. The data show that RETs can serve as an appropriate indicator cell population for 28-day studies. Collectively, these data suggest that blood-based genotoxicity endpoints can be effectively incorporated into routine toxicology studies, a strategy that would reduce animal usage while providing valuable genetic toxicity information within the context of other toxicological endpoints. PMID:20202993

  17. The Sleep Apnea cardioVascular Endpoints (SAVE) Trial: Rationale, Ethics, Design, and Progress

    PubMed Central

    Antic, Nick A.; Heeley, Emma; Anderson, Craig S.; Luo, Yuanming; Wang, Jiguang; Neal, Bruce; Grunstein, Ron; Barbe, Ferran; Lorenzi-Filho, Geraldo; Huang, Shaoguang; Redline, Susan; Zhong, Nanshan; McEvoy, R. Doug

    2015-01-01

    The Sleep Apnea cardioVascular Endpoints (SAVE) study is an ongoing investigator-initiated and conducted, international, multicenter, open, blinded endpoint, randomized controlled trial that was designed to determine whether treatment of obstructive sleep apnea (OSA) with continuous positive airways pressure (CPAP) can reduce the risk of serious cardiovascular (CV) events in patients with established CV disease (clinical trial registration NCT00738179). The results of this study will have important implications for the provision of health care to patients with sleep apnea around the world. The SAVE study has brought together respiratory, sleep, CV and stroke clinicians-scientists in an interdisciplinary collaboration with industry and government sponsorship to conduct an ambitious clinical trial. Following its launch in Australia and China in late 2008, the recruitment network expanded across 89 sites that included New Zealand, India, Spain, USA, and Brazil for a total of 2,717 patients randomized by December 2013. These patients are being followed until December 2015 so that the average length of follow-up of the cohort will be over 4 y. This article describes the rationale for the SAVE study, considerations given to the design including how various cultural and ethical challenges were addressed, and progress in establishing and maintaining the recruitment network, patient follow-up, and adherence to CPAP and procedures. The assumptions underlying the original trial sample size calculation and why this was revised downward in 2012 are also discussed. Clinical Trials Registration Number: NCT00738179. Australia New Zealand Clinical Trials Registry Number: ACTRN12608000409370. Citation: Antic NA, Heeley E, Anderson CS, Luo Y, Wang J, Neal B, Grunstein R, Barbe F, Lorenzi-Filho G, Huang S, Redline S, Zhong N, McEvoy RD. The sleep apnea cardiovascular endpoints (SAVE) trial: rationale, ethics, design, and progress. SLEEP 2015;38(8):1247–1257. PMID:25669180

  18. Use of behavioral endpoints to determine protective concentrations of the insecticide fonofos for bluegill (Lepomis macrochirus)

    USGS Publications Warehouse

    Fairchild, J.F.; Little, E.E.

    1999-01-01

    This research compared the results of laboratory and mesocosm studies to determine the effectiveness of using behavioral measures of sublethal exposure to define environmental concentration ranges that are protective of free-ranging populations of bluegill (Lepomis macrochirus) exposed to the organophophate insecticide fonofos. Thirty-day laboratory chronic studies were conducted to determine the relative sensitivity of standard (e.g. survival and growth) and non-standard behavioral (e.g. swimming capacity, feeding efficiency, and aggression) endpoints in predicting concentrations of fonofos protective of bluegill growth and survival. The lowest observable effect concentration (LOECs) for the standard measures of survival and growth was 5.6 ??g/L. Two behavioral endpoints were of similar sensitivity to the standard measures: swimming capacity, LOEC of 5.6 ??g/L; and prey strike frequency, LOEC of 5.6 ??g/L. However, aggressive interactions were ten-fold more sensitive than swimming or feeding behavior with a LOEC occurring at 0.6 ??g/L. Lab results were compared to an aquatic mesocosm study which exposed adult and juvenile bluegill to a 9.41 ??g/L concentration of fonofos. The dissipation half-life of fonofos was 5 days in 0.1 hectare aquatic mesocosms. Significant mortality among caged bluegill occurred within 4 days of exposure at 9.41 ??g/L. However, the 9.41 ??g/L concentration of fonofos had no statistically significant effects on survival, growth, reproduction, or total biomass of free-ranging populations of bluegill. We conclude from these studies that laboratory data can accurately estimate concentrations that are lethal in the field and that the use of behavioral endpoints can provide ecologically relevant, yet conservative estimates of concentrations that are protective of field populations.

  19. Application of molecular endpoints in early life stage salmonid environmental biomonitoring.

    PubMed

    Marlatt, Vicki L; Sherrard, Ryan; Kennedy, Chris J; Elphick, James R; Martyniuk, Christopher J

    2016-04-01

    Molecular endpoints can enhance existing whole animal bioassays by more fully characterizing the biological impacts of aquatic pollutants. Laboratory and field studies were used to examine the utility of adopting molecular endpoints for a well-developed in situ early life stage (eyed embryo to onset of swim-up fry) salmonid bioassay to improve diagnostic assessments of water quality in the field. Coastal cutthroat trout (Oncorhynchus clarki clarki) were exposed in the laboratory to the model metal (zinc, 40μg/L) and the polycyclic aromatic hydrocarbon (pyrene, 100μg/L) in water to examine the resulting early life stage salmonid responses. In situ field exposures and bioassays were conducted in parallel to evaluate the water quality of three urban streams in British Columbia (two sites with anthropogenic inputs and one reference site). The endpoints measured in swim-up fry included survival, deformities, growth (weight and length), vitellogenin (vtg) and metallothionein (Mt) protein levels, and hepatic gene expression (e.g., metallothioneins [mta and mtb], endocrine biomarkers [vtg and estrogen receptors, esr] and xenobiotic-metabolizing enzymes [cytochrome P450 1A3, cyp1a3 and glutathione transferases, gstk]). No effects were observed in the zinc treatment, however exposure of swim-up fry to pyrene resulted in decreased survival, deformities and increased estrogen receptor alpha (er1) mRNA levels. In the field exposures, xenobiotic-metabolizing enzymes (cyp1a3, gstk) and zinc transporter (zntBigM103) mRNA were significantly increased in swim-up fry deployed at the sites with more anthropogenic inputs compared to the reference site. Cluster analysis revealed that gene expression profiles in individuals from the streams receiving anthropogenic inputs were more similar to each other than to the reference site. Collectively, the results obtained in this study suggest that molecular endpoints may be useful, and potentially more sensitive, indicators of site

  20. Adverse effect of agroecosystem pond water on biological endpoints of common toad (Rhinella arenarum) tadpoles.

    PubMed

    Babini, María Selene; Bionda, Clarisa de Lourdes; Salas, Nancy Edith; Martino, Adolfo Ludovico

    2016-08-01

    Chemical prroducts used in farming and wastes from livestock can contaminate pond water in agroecosystems due to runoff. Amphibians using these ponds for breeding are probably exposed to pollutants, and serious consequences might be observed afterward at the population level. Assessment biological endpoints of anuran to water quality give a realistic estimate of the probability of occurrence of adverse effects and provide an early warning signal. In this study, the ecotoxicity of agroecosystem ponds from the south of Córdoba province, Argentina, was investigated. Ponds in four sites with different degrees of human disturbance were selected: three agroecosystems (A1, A2, A3) and a site without crops or livestock (SM). The effect of pond water quality on the biological endpoint of Rhinella arenarum tadpoles was examined using microcosms with pond water from sites. Biological endpoints assessed were as follows: mortality, growth, development, morphological abnormalities (in body shape, gut, and labial tooth row formula), behavior, and blood cell parameters (micronucleus and nuclear abnormalities). Results indicated that water from agroecosystems has adverse effect on early life stage of R. arenarum. High mortality and fewer metamorphs were recorded in the A1 and A3 treatments. Tadpoles and metamorphs from A1 and A2 treatments had lower body condition. Tadpoles from A1 and A3 showed the highest prevalence of morphological abnormalities. The lowest amount of tadpoles feeding and the highest percentage of tadpoles swimming on the surface were observed in treatments with agroecosystem pond water. The higher frequencies of micronuclei and nuclear abnormalities were recorded in tadpoles from A1, A2, and A3 treatments. We check the sensitivity of the biological endpoints of R. arenarum tadpoles like early warning indicators of water quality. We found that the poor water quality of agroecosystem ponds has impact on the health of the tadpoles, and this could affect the

  1. Regulation of the Embryonic Cell Cycle During Mammalian Preimplantation Development.

    PubMed

    Palmer, N; Kaldis, P

    2016-01-01

    The preimplantation development stage of mammalian embryogenesis consists of a series of highly conserved, regulated, and predictable cell divisions. This process is essential to allow the rapid expansion and differentiation of a single-cell zygote into a multicellular blastocyst containing cells of multiple developmental lineages. This period of development, also known as the germinal stage, encompasses several important developmental transitions, which are accompanied by dramatic changes in cell cycle profiles and dynamics. These changes are driven primarily by differences in the establishment and enforcement of cell cycle checkpoints, which must be bypassed to facilitate the completion of essential cell cycle events. Much of the current knowledge in this area has been amassed through the study of knockout models in mice. These mouse models are powerful experimental tools, which have allowed us to dissect the relative dependence of the early embryonic cell cycles on various aspects of the cell cycle machinery and highlight the extent of functional redundancy between members of the same gene family. This chapter will explore the ways in which the cell cycle machinery, their accessory proteins, and their stimuli operate during mammalian preimplantation using mouse models as a reference and how this allows for the usually well-defined stages of the cell cycle to be shaped and transformed during this unique and critical stage of development. PMID:27475848

  2. The New Federalism: State Policies Regarding Embryonic Stem Cell Research.

    PubMed

    Acosta, Nefi D; Golub, Sidney H

    2016-09-01

    Stem cell policy in the United States is an amalgam of federal and state policies. The scientific development of human pluripotent embryonic stem cells (ESCs) triggered a contentious national stem cell policy debate during the administration of President George W. Bush. The Bush "compromise" that allowed federal funding to study only a very limited number of ESC derived cell lines did not satisfy either the researchers or the patient advocates who saw great medical potential being stifled. Neither more restrictive legislation nor expansion of federal funding proved politically possible and the federal impasse opened the door for a variety of state-based experiments. In 2004, California became the largest and most influential state venture into stem cell research by passing "Prop 71," a voter initiative that created a new stem cell agency and funded it with $3 billion. Several states followed suit with similar programs to protect the right of investigators to do stem cell research and in some cases to invest state funding in such projects. Other states devised legislation to restrict stem cell research and in five states, criminal penalties were included. Thus, the US stem cell policy is a patchwork of multiple, often conflicting, state and federal policies. PMID:27587447

  3. Adrenergic DNA damage of embryonic pluripotent cells via β2 receptor signalling

    PubMed Central

    Sun, Fan; Ding, Xu-Ping; An, Shi-Min; Tang, Ya-Bin; Yang, Xin-Jie; Teng, Lin; Zhang, Chun; Shen, Ying; Chen, Hong-Zhuan; Zhu, Liang

    2015-01-01

    Embryonic pluripotent cells are sensitive to genotoxicity though they need more stringent genome integrity to avoid compromising multiple cell lineages and subsequent generations. However it remains unknown whether the cells are susceptible to adrenergic stress which can induce somatic cell genome lesion. We have revealed that adrenergic stress mediators cause DNA damage of the cells through the β2 adrenergic receptor/adenylate cyclase/cAMP/PKA signalling pathway involving an induction of intracellular reactive oxygen species (ROS) accumulation. The adrenergic stress agonists adrenaline, noradrenaline, and isoprenaline caused DNA damage and apoptosis of embryonic stem (ES) cells and embryonal carcinoma stem cells. The effects were mimicked by β2 receptor-coupled signalling molecules and abrogated by selective blockade of β2 receptors and inhibition of the receptor signalling pathway. RNA interference targeting β2 receptors of ES cells conferred the cells the ability to resist the DNA damage and apoptosis. In addition, adrenergic stimulation caused a consistent accumulation of ROS in the cells and the effect was abrogated by β2 receptor blockade; quenching of ROS reversed the induced DNA damage. This finding will improve the understanding of the stem cell regulatory physiology/pathophysiology in an adrenergic receptor subtype signalling mechanism. PMID:26516061

  4. Triennial Reproduction Symposium: influence of follicular characteristics at ovulation on early embryonic survival.

    PubMed

    Geary, T W; Smith, M F; MacNeil, M D; Day, M L; Bridges, G A; Perry, G A; Abreu, F M; Atkins, J A; Pohler, K G; Jinks, E M; Madsen, C A

    2013-07-01

    Reproductive failure in livestock can result from failure to fertilize the oocyte or embryonic loss during gestation. Although fertilization failure occurs, embryonic mortality represents a greater contribution to reproductive failure. Reproductive success varies among species and production goals but is measured as a binomial trait (i.e., pregnancy), derived by the success or failure of multiple biological steps. This review focuses primarily on follicular characteristics affecting oocyte quality, fertilization, and embryonic health that lead to pregnancy establishment in beef cattle. When estrous cycles are manipulated with assisted reproductive technologies and ovulation is induced, duration of proestrus (i.e., interval from induced luteolysis to induced ovulation), ovulatory follicle growth rate, and ovulatory follicle size are factors that affect the maturation of the follicle and oocyte at induced ovulation. The most critical maturational component of the ovulatory follicle is the production of sufficient estradiol to prepare follicular cells for luteinization and progesterone synthesis and prepare the uterus for pregnancy. The exact roles of estradiol in oocyte maturation remain unclear, but cows that have lesser serum concentrations of estradiol have decreased fertilization rates and decreased embryo survival on d 7 after induced ovulation. When length of proestrus is held constant, perhaps the most practical follicular measure of fertility is ovulatory follicle size because it is an easily measured attribute of the follicle that is highly associated with its ability to produce estradiol. PMID:23230106

  5. The zinc finger transcription factor 191 is required for early embryonic development and cell proliferation

    SciTech Connect

    Li Jianzhong; Chen Xia; Yang Hua; Wang Shuiliang; Guo Baoyu; Yu Long; Wang Zhugang; Fu Jiliang . E-mail: fu825@mail.tongji.edu.cn

    2006-12-10

    Human zinc finger protein 191 (ZNF191/ZNF24) was cloned and characterized as a SCAN family member, which shows 94% identity to its mouse homologue zinc finger protein 191 (Zfp191). ZNF191 can specifically interact with an intronic polymorphic TCAT repeat (HUMTH01) in the tyrosine hydroxylase (TH) gene. Allelic variations of HUMTH01 have been stated to have a quantitative silencing effect on TH gene expression and to correlate with quantitative and qualitative changes in the binding by ZNF191. Zfp191 is widely expressed during embryonic development and in multiple tissues and organs in adult. To investigate the functions of Zfp191 in vivo, we have used homologous recombination to generate mice that are deficient in Zfp191. Heterozygous Zfp191 {sup +/-} mice are normal and fertile. Homozygous Zfp191 {sup -/-} embryos are severely retarded in development and die at approximately 7.5 days post-fertilization. Unexpectedly, in Zfp191 {sup -/-} and Zfp191 {sup +/-} embryos, TH gene expression is not affected. Blastocyst outgrowth experiments and the RNA interference-mediated knockdown of ZNF191 in cultured cells revealed an essential role for Zfp191 in cell proliferation. In further agreement with this function, no viable Zfp191 {sup -/-} cell lines were obtained by derivation of embryonic stem (ES) cells from blastocysts of Zfp191 {sup +/-} intercrosses or by forced homogenotization of heterozygous ES cells at high concentrations of G418. These data show that Zfp191 is indispensable for early embryonic development and cell proliferation.

  6. Early embryonic intra-cardiac flow fields at three idealized ventricular morphologies

    NASA Astrophysics Data System (ADS)

    Pekkan, Kerem; Jamaly, Mohammad; Kara, Burak; Keller, Bradley; Sotiropoulos, Fotis

    2009-11-01

    Pulsatile 3D multiple inlet/outlet flow within tiny (100-300μm dia) embryonic ventricles feature distinct intra-cardiac flow streams whose role in regulating the morphogenesis of spiral aorto-pulmonary septum has long been debated. The low Re number flow regimes limit mixing of these streams as replicated in our flow-visualization experiments with chick embryos. A state-of-the art high-resolution immersed boundary CFD solver which was developed for complex patient-specific cardiovascular internal flow problems is applied and optimized for this problem. Idealized tubular ventricles at 3 major embryonic stages (straight, C- and D- loops) are created by our sketch-based anatomical editing tool. CFD results are validated with PIV measurements acquired from a micro-fabricated C-loop stage replica and in vivo flow vis data from confocal microscopy. This model provided the inlet velocity profile for arterial models and flow fields at the inner curvature of embryonic hearts for different ventricular topologies are compared for off-design modes.

  7. An Integrated Transcriptome Atlas of Embryonic Hair Follicle Progenitors, Their Niche, and the Developing Skin.

    PubMed

    Sennett, Rachel; Wang, Zichen; Rezza, Amélie; Grisanti, Laura; Roitershtein, Nataly; Sicchio, Cristina; Mok, Ka Wai; Heitman, Nicholas J; Clavel, Carlos; Ma'ayan, Avi; Rendl, Michael

    2015-09-14

    Defining the unique molecular features of progenitors and their niche requires a genome-wide, whole-tissue approach with cellular resolution. Here, we co-isolate embryonic hair follicle (HF) placode and dermal condensate cells, precursors of adult HF stem cells and the dermal papilla/sheath niche, along with lineage-related keratinocytes and fibroblasts, Schwann cells, melanocytes, and a population inclusive of all remaining skin cells. With next-generation RNA sequencing, we define gene expression patterns in the context of the entire embryonic skin, and through transcriptome cross-comparisons, we uncover hundreds of enriched genes in cell-type-specific signatures. Axon guidance signaling and many other pathway genes are enriched in multiple signatures, implicating these factors in driving the large-scale cellular rearrangements necessary for HF formation. Finally, we share all data in an interactive, searchable companion website. Our study provides an overarching view of signaling within the entire embryonic skin and captures a molecular snapshot of HF progenitors and their niche. PMID:26256211

  8. Sample Size Considerations in Clinical Trials when Comparing Two Interventions using Multiple Co-Primary Binary Relative Risk Contrasts

    PubMed Central

    Ando, Yuki; Hamasaki, Toshimitsu; Evans, Scott R.; Asakura, Koko; Sugimoto, Tomoyuki; Sozu, Takashi; Ohno, Yuko

    2015-01-01

    The effects of interventions are multi-dimensional. Use of more than one primary endpoint offers an attractive design feature in clinical trials as they capture more complete characterization of the effects of an intervention and provide more informative intervention comparisons. For these reasons, multiple primary endpoints have become a common design feature in many disease areas such as oncology, infectious disease, and cardiovascular disease. More specifically in medical product development, multiple endpoints are utilized as co-primary to evaluate the effect of the new interventions. Although methodologies to address continuous co-primary endpoints are well-developed, methodologies for binary endpoints are limited. In this paper, we describe power and sample size determination for clinical trials with multiple correlated binary endpoints, when relative risks are evaluated as co-primary. We consider a scenario where the objective is to evaluate evidence for superiority of a test intervention compared with a control intervention, for all of the relative risks. We discuss the normal approximation methods for power and sample size calculations and evaluate how the required sample size, power and Type I error vary as a function of the correlations among the endpoints. Also we discuss a simple, but conservative procedure for appropriate sample size calculation. We then extend the methods allowing for interim monitoring using group-sequential methods. PMID:26167243

  9. Engineering tissue from human embryonic stem cells

    PubMed Central

    Metallo, CM; Azarin, SM; Ji, L; De Pablo, JJ; Palecek, SP

    2008-01-01

    Abstract Recent advances in human embryonic stem cell (hESC) biology now offer an alternative cell source for tissue engineers, as these cells are capable of proliferating indefinitely and differentiating to many clinically relevant cell types. Novel culture methods capable of exerting spatial and temporal control over the stem cell microenvironment allow for more efficient expansion of hESCs, and significant advances have been made toward improving our understanding of the biophysical and biochemical cues that direct stem cell fate choices. Effective production of lineage specific progenitors or terminally differentiated cells enables researchers to incorporate hESC derivatives into engineered tissue constructs. Here, we describe current efforts using hESCs as a cell source for tissue engineering applications, highlighting potential advantages of hESCs over current practices as well as challenges which must be overcome. PMID:18194458

  10. Human embryonic stem cells: preclinical perspectives

    PubMed Central

    Deb, Kaushik Dilip; Sarda, Kanchan

    2008-01-01

    Human embryonic stem cells (hESCs) have been extensively discussed in public and scientific communities for their potential in treating diseases and injuries. However, not much has been achieved in turning them into safe therapeutic agents. The hurdles in transforming hESCs to therapies start right with the way these cells are derived and maintained in the laboratory, and goes up-to clinical complications related to need for patient specific cell lines, gender specific aspects, age of the cells, and several post transplantation uncertainties. The different types of cells derived through directed differentiation of hESC and used successfully in animal disease and injury models are described briefly. This review gives a brief outlook on the present and the future of hESC based therapies, and talks about the technological advances required for a safe transition from laboratory to clinic. PMID:18230169

  11. Embryonal brain tumors and developmental control genes

    SciTech Connect

    Aguzzi, A.

    1995-12-31

    Cell proliferation in embryogenesis and neoplastic transformation is thought to be controlled by similar sets of regulatory genes. This is certainly true for tumors of embryonic origin, such as Ewing sarcoma, Wilms` tumor and retinoblastoma, in which developmental control genes are either activated as oncogenes to promote proliferation, or are inactivated to eliminate their growth suppressing function. However, to date little is known about the genetic events underlying the pathogenesis of medulloblastoma, the most common brain tumor in children, which still carries an unfavourable prognosis. None of the common genetic alterations identified in other neuroectodermal tumors, such as mutation of the p53 gene or amplification of tyrosine kinase receptor genes, could be uncovered as key events in the formation of medulloblastoma. The identification of regulatory genes which are expressed in this pediatric brain tumor may provide an alternative approach to gain insight into the molecular aspects of tumor formation.

  12. Metabolic differentiation in the embryonic retina.

    PubMed

    Agathocleous, Michalis; Love, Nicola K; Randlett, Owen; Harris, Julia J; Liu, Jinyue; Murray, Andrew J; Harris, William A

    2012-08-01

    Unlike healthy adult tissues, cancers produce energy mainly by aerobic glycolysis instead of oxidative phosphorylation. This adaptation, called the Warburg effect, may be a feature of all dividing cells, both normal and cancerous, or it may be specific to cancers. It is not known whether, in a normally growing tissue during development, proliferating and postmitotic cells produce energy in fundamentally different ways. Here we show in the embryonic Xenopus retina in vivo, that dividing progenitor cells depend less on oxidative phosphorylation for ATP production than non-dividing differentiated cells, and instead use glycogen to fuel aerobic glycolysis. The transition from glycolysis to oxidative phosphorylation is connected to the cell differentiation process. Glycolysis is indispensable for progenitor proliferation and biosynthesis, even when it is not used for ATP production. These results suggest that the Warburg effect can be a feature of normal proliferation in vivo, and that the regulation of glycolysis and oxidative phosphorylation is critical for normal development. PMID:22750943

  13. Embryonic and adult stem cell therapy.

    PubMed

    Brignier, Anne C; Gewirtz, Alan M

    2010-02-01

    There are many types of stem cells. All share the characteristics of being able to self-renew and to give rise to differentiated progeny. Over the last decades, great excitement has been generated by the prospect of being able to exploit these properties for the repair, improvement, and/or replacement of damaged organs. However, many hurdles, both scientific and ethical, remain in the path of using human embryonic stem cells for tissue-engineering purposes. In this report we review current strategies for isolating, enriching, and, most recently, inducing the development of human pluripotent stem cells. In so doing, we discuss the scientific and ethical issues associated with this endeavor. Finally, progress in the use of stem cells as therapies for type 1 diabetes mellitus, congestive heart failure, and various neurologic and immunohematologic disorders, and as vehicles for the delivery of gene therapy, is briefly discussed. PMID:20061008

  14. Will embryonic stem cells change health policy?

    PubMed

    Sage, William M

    2010-01-01

    Embryonic stem cells are actively debated in political and public policy arenas. However, the connections between stem cell innovation and overall health care policy are seldom elucidated. As with many controversial aspects of medical care, the stem cell debate bridges to a variety of social conversations beyond abortion. Some issues, such as translational medicine, commercialization, patient and public safety, health care spending, physician practice, and access to insurance and health care services, are core health policy concerns. Other issues, such as economic development, technologic progress, fiscal politics, and tort reform, are only indirectly related to the health care system but are frequently seen through a health care lens. These connections will help determine whether the stem cell debate reaches a resolution, and what that resolution might be. PMID:20579256

  15. Debating restrictions on embryonic stem cell research.

    PubMed

    McClain, Colleen

    2009-09-01

    This study investigates the emotional and behavioral effects of interpersonal online communication, focusing on the controversy surrounding the loosening of restrictions on human embryonic stem cell research. The issue, central to national and statewide elections in 2008, generated heated debate among candidates and voters and evoked strong emotional sentiments among partisans. Using the theory of affective intelligence, this study proposes a predictive model connecting levels of enthusiasm and anxiety with behavioral and information-seeking outcomes. Cognitive appraisal theory is also employed to provide a role for political emotion in accounting for interactive media effects. To investigate the ways that online deliberation may influence discussions surrounding stem cell research, a between-subjects experimental study was conducted that systematically varied the tone of feedback received (reinforcing or challenging) and type of interaction (synchronous or asynchronous) experienced by users. Results indicate that emotional responses play a significant role in predicting behavioral intentions arising from the user-to-user interactive experience. PMID:20205522

  16. Observations on the source of embryonic myocardioblasts.

    PubMed Central

    Morris, E W

    1976-01-01

    The light and electron microscopic appearance of mesenchymal and myoblastic tissue in the embryonic heart is described. The similarity in the morphological appearance of all mesenchymal cells is pointed out, whether they occur in atrioventricular cushion tissue, the ridge tissue of the bulbus, cordis, sub-epicardial tissue or in mesenchyme elsewhere in the embryo. Cells intermediate in their ultrastructure between mesenchymal cells and myoblasts are found. The significance of such cells is discussed and the suggestion made that their appearance is consistent with their representing stages in the differentiation of mesenchymal cells into myoblasts. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 PMID:1254531

  17. Imprinted expression in cystic embryoid bodies shows an embryonic and not an extra-embryonic pattern

    PubMed Central

    Kulinski, Tomasz M.; Casari, M. Rita T.; Guenzl, Philipp M.; Wenzel, Daniel; Andergassen, Daniel; Hladik, Anastasiya; Datlinger, Paul; Farlik, Matthias; Theussl, H. -Christian; Penninger, Josef M.; Knapp, Sylvia; Bock, Christoph; Barlow, Denise P.; Hudson, Quanah J.

    2015-01-01

    A large subset of mammalian imprinted genes show extra-embryonic lineage (EXEL) specific imprinted expression that is restricted to placental trophectoderm lineages and to visceral yolk sac endoderm (ysE). Isolated ysE provides a homogenous in vivo model of a mid-gestation extra-embryonic tissue to examine the mechanism of EXEL-specific imprinted gene silencing, but an in vitro model of ysE to facilitate more rapid and cost-effective experiments is not available. Reports indicate that ES cells differentiated into cystic embryoid bodies (EBs) contain ysE, so here we investigate if cystic EBs model ysE imprinted expression. The imprinted expression pattern of cystic EBs is shown to resemble fetal liver and not ysE. To investigate the reason for this we characterized the methylome and transcriptome of cystic EBs in comparison to fetal liver and ysE, by whole genome bisulphite sequencing and RNA-seq. Cystic EBs show a fetal liver pattern of global hypermethylation and low expression of repeats, while ysE shows global hypomethylation and high expression of IAPEz retroviral repeats, as reported for placenta. Transcriptome analysis confirmed that cystic EBs are more similar to fetal liver than ysE and express markers of early embryonic endoderm. Genome-wide analysis shows that ysE shares epigenetic and repeat expression features with placenta. Contrary to previous reports, we show that cystic EBs do not contain ysE, but are more similar to the embryonic endoderm of fetal liver. This explains why cystic EBs reproduce the imprinted expression seen in the embryo but not that seen in the ysE. PMID:25912690

  18. Embryonic development of the cricket Gryllus bimaculatus.

    PubMed

    Donoughe, Seth; Extavour, Cassandra G

    2016-03-01

    Extensive research into Drosophila melanogaster embryogenesis has improved our understanding of insect developmental mechanisms. However, Drosophila development is thought to be highly divergent from that of the ancestral insect and arthropod in many respects. We therefore need alternative models for arthopod development that are likely to be more representative of basally-branching clades. The cricket Gryllus bimaculatus is such a model, and currently has the most sophisticated functional genetic toolkit of any hemimetabolous insect. The existing cricket embryonic staging system is fragmentary, and it is based on morphological landmarks that are not easily visible on a live, undissected egg. To address this problem, here we present a complementary set of "egg stages" that serve as a guide for identifying the developmental progress of a cricket embryo from fertilization to hatching, based solely on the external appearance of the egg. These stages were characterized using a combination of brightfield timelapse microscopy, timed brightfield micrographs, confocal microscopy, and measurements of egg dimensions. These egg stages are particularly useful in experiments that involve egg injection (including RNA interference, targeted genome modification, and transgenesis), as injection can alter the speed of development, even in control treatments. We also use 3D reconstructions of fixed embryo preparations to provide a comprehensive description of the morphogenesis and anatomy of the cricket embryo during embryonic rudiment assembly, germ band formation, elongation, segmentation, and appendage formation. Finally, we aggregate and schematize a variety of published developmental gene expression patterns. This work will facilitate further studies on G. bimaculatus development, and serve as a useful point of reference for other studies of wild type and experimentally manipulated insect development in fields from evo-devo to disease vector and pest management. PMID:25907229

  19. YAP/TAZ enhance mammalian embryonic neural stem cell characteristics in a Tead-dependent manner

    SciTech Connect

    Han, Dasol; Byun, Sung-Hyun; Park, Soojeong; Kim, Juwan; Kim, Inhee; Ha, Soobong; Kwon, Mookwang; Yoon, Keejung

    2015-02-27

    Mammalian brain development is regulated by multiple signaling pathways controlling cell proliferation, migration and differentiation. Here we show that YAP/TAZ enhance embryonic neural stem cell characteristics in a cell autonomous fashion using diverse experimental approaches. Introduction of retroviral vectors expressing YAP or TAZ into the mouse embryonic brain induced cell localization in the ventricular zone (VZ), which is the embryonic neural stem cell niche. This change in cell distribution in the cortical layer is due to the increased stemness of infected cells; YAP-expressing cells were colabeled with Sox2, a neural stem cell marker, and YAP/TAZ increased the frequency and size of neurospheres, indicating enhanced self-renewal- and proliferative ability of neural stem cells. These effects appear to be TEA domain family transcription factor (Tead)–dependent; a Tead binding-defective YAP mutant lost the ability to promote neural stem cell characteristics. Consistently, in utero gene transfer of a constitutively active form of Tead2 (Tead2-VP16) recapitulated all the features of YAP/TAZ overexpression, and dominant negative Tead2-EnR resulted in marked cell exit from the VZ toward outer cortical layers. Taken together, these results indicate that the Tead-dependent YAP/TAZ signaling pathway plays important roles in neural stem cell maintenance by enhancing stemness of neural stem cells during mammalian brain development. - Highlights: • Roles of YAP and Tead in vivo during mammalian brain development are clarified. • Expression of YAP promotes embryonic neural stem cell characteristics in vivo in a cell autonomous fashion. • Enhancement of neural stem cell characteristics by YAP depends on Tead. • Transcriptionally active form of Tead alone can recapitulate the effects of YAP. • Transcriptionally repressive form of Tead severely reduces stem cell characteristics.

  20. Effects of developmental stage, salts, and food presence on aquatic toxicological endpoints using Caenorhabditis elegans

    SciTech Connect

    Donkin, S.G.; Williams, P.L.

    1995-12-31

    The objective of this study was to standardize the testing protocol for aquatic toxicity tests with the nematode Caenorhabditis elegans. Several variables which may be important in determining the test outcome were investigated in a randomized block design. Concentration-response data were obtained on nematodes of various developmental stages exposed to four metals (Cd, Pb, Cu, and Hg) and a water-soluble organic toxicant, sodium Pentachlorophenate (PCP), under conditions of varied solvent medium (with or without salts and with or without a bacterial food source). The endpoints measured were 24 and 96-h mortality, as well as development of larval stages to adulthood and evidence of reproduction. The results suggest that nematodes of various ages respond similarly to a given toxicant for all endpoints measured, although adults cultured from eggs appeared more sensitive than adults cultured from dauer larvae. The most important environmental variable in determining toxicity was the medium in which the tests were conducted. The presence of potassium and sodium salts in the medium significantly (p<0.05) reduced the toxicity of many test samples. The presence of bacteria had little effect on 24-h tests with salts, but was important in 96-h survival and development. Based on sensitivity and ease of handling, adults cultured from eggs are recommended in both 24-h and 96-h mortality (LC50 value) tests, as well as 96-h reproduction tests.

  1. Ecotoxicological endpoints, are they useful tools to support ecological status assessment in strongly modified water bodies?

    PubMed

    Palma, P; Ledo, L; Alvarenga, P

    2016-01-15

    Although man-made reservoirs represent an important water supply source in countries where water scarcity has become a problem, little work has been done on the evaluation of their ecological status. Taking this in account, the general aim of this study was to assess the usefulness of ecotoxicological endpoints in the potential ecological status characterization of water reservoirs, with the purpose of their possible integration in evaluation programs developed under the Water Framework Directive (WFD). To achieve this purpose, a group of bioassays were selected to evaluate both water and sediment compartments at the Alqueva reservoir (the biggest from the Iberian Peninsula), with representative species from different taxonomic and functional groups: Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna and Heterocypris incongruens. The ecotoxicological assessment showed that sublethal endpoints (e.g., luminescence, growth or reproduction), would be more useful and sensitive to identify toxicity patterns in this type of water body. In general, the results from this ecotoxicological toolbox agreed with the potential ecological status established according to the WFD, which indicates that the bioassays complement the ecological assessment. Furthermore, the use of an ecotoxicological approach can be extremely useful, especially in cases where the biotic indices are difficult to establish, such as in man-made reservoirs. However, when pollutant concentrations are very low, and/or when nutrients and organic matter concentrations are high, the two approaches do not fit, requiring further research to determine which organisms are more sensitive and the best biotic indices to use under those conditions. PMID:26402482

  2. Safety and Efficacy Endpoints for Mesenchymal Stromal Cell Therapy in Renal Transplant Recipients

    PubMed Central

    Bank, J. R.; Rabelink, T. J.; de Fijter, J. W.; Reinders, M. E. J.

    2015-01-01

    Despite excellent short-term graft survival after renal transplantation, the long-term graft outcome remains compromised. It has become evident that a combination of sustained alloreactivity and calcineurin-inhibitor- (CNI-) related nephrotoxicity results in fibrosis and consequently dysfunction of the graft. New immunosuppressive regimens that can minimize or eliminate side effects, while maintaining efficacy, are required to improve long-term graft survival. In this perspective mesenchymal stromal cells (MSCs) are an interesting candidate, since MSCs have immunosuppressive and regenerative properties. The first clinical trials with MSCs in renal transplantation showed safety and feasibility and displayed promising results. Recently, the first phase II studies have been started. One of the most difficult and challenging aspects in those early phase trials is to define accurate endpoints that can measure safety and efficacy of MSC treatment. Since both graft losses and acute rejection rates declined, alternative surrogate markers such as renal function, histological findings, and immunological markers are used to measure efficacy and to provide mechanistic insight. In this review, we will discuss the current status of MSCs in renal transplantation with a focus on the endpoints used in the different experimental and clinical studies. PMID:26258149

  3. General description of electromagnetic radiation processes based on instantaneous charge acceleration in ''endpoints''

    SciTech Connect

    James, Clancy W.; Falcke, Heino; Huege, Tim; Ludwig, Marianne

    2011-11-15

    We present a methodology for calculating the electromagnetic radiation from accelerated charged particles. Our formulation - the 'endpoint formulation' - combines numerous results developed in the literature in relation to radiation arising from particle acceleration using a complete, and completely general, treatment. We do this by describing particle motion via a series of discrete, instantaneous acceleration events, or 'endpoints', with each such event being treated as a source of emission. This method implicitly allows for particle creation and destruction, and is suited to direct numerical implementation in either the time or frequency domains. In this paper we demonstrate the complete generality of our method for calculating the radiated field from charged particle acceleration, and show how it reduces to the classical named radiation processes such as synchrotron, Tamm's description of Vavilov-Cherenkov, and transition radiation under appropriate limits. Using this formulation, we are immediately able to answer outstanding questions regarding the phenomenology of radio emission from ultra-high-energy particle interactions in both the earth's atmosphere and the moon. In particular, our formulation makes it apparent that the dominant emission component of the Askaryan effect (coherent radio-wave radiation from high-energy particle cascades in dense media) comes from coherent 'bremsstrahlung' from particle acceleration, rather than coherent Vavilov-Cherenkov radiation.

  4. Challenges to the Therapeutic Pipeline for Irritable Bowel Syndrome: Endpoints and Regulatory Hurdles

    PubMed Central

    Camilleri, Michael; Chang, Lin

    2008-01-01

    Recent advances in our understanding of basic neuroenteric mechanisms and the role of effectors and transmitters in the brain-gut axis have provided opportunities to develop new therapeutic agents for irritable bowel syndrome (IBS). Furthermore, human pharmacodynamic studies utilizing transit, colonic or rectal sensitivity, and brain imaging have been useful in determining therapeutic efficacy (particularly for drugs that act on motor function). This review provides an overview of medications that have not yet been approved for treatment of patients with IBS, yet have shown promise in phase IIB trials. These include drugs that act on the serotonin receptor and transporter system, antidepressants, norepinephrine reuptake inhibitors, opioids, cholecystokinin antagonists, neurokinin-antagonists, chloride channel activators, guanylate cyclase C agonists, atypical benzodiazepines, probiotics and antibiotics. The changing landscape in the regulatory approval process has impacted the development of IBS drugs. Guidance documents from regulatory agencies in Europe and the United States have focused on patients’ reported outcomes and associated quality of life. After a decade of experience with different endpoints that have generated some data on psychometric validation and unprecedented information about responsiveness of the binary or global endpoints to drug therapy, it is necessary to pursue further validation studies before or during pivotal phase IIB or III trials. The hope of providing relief to patients should galvanize all parties to achieve these goals. PMID:18848833

  5. Pathology assessment is necessary to validate translational endpoints in preclinical aging studies

    PubMed Central

    Ladiges, Warren

    2016-01-01

    The Geropathology Research Network has established a plan to identify and use pathology-based surrogate endpoints for aging intervention in preclinical drug studies to provide a predictable and short-term anti-aging drug response in line with clinical trials. The plan involves pathological assessment of tissues and organs from strains of old mice, by independent pathology groups in a concurrent manner in order to characterize the changes in lesion incidence and severity in response to anti-aging drugs at specific time points. This approach allows for connection with translational endpoints of aging, such as serum factors and physiological parameters, between mice and humans. Preclinical drug testing is a critical component of the plan, designed to shorten testing times from lengthy lifespan studies by comparing lesion grades and composite scores in treated and placebo cohorts at cross-sectional time points. In conclusion, a geropathology-based preclinical testing program is a step toward assuring maximum utilization of translational resources and increasing predictability of efficacy of new or repurposed drugs for clinical aging intervention studies. PMID:27015829

  6. Special endpoint and product specific considerations in pharmaceutical acceptable daily exposure derivation.

    PubMed

    Gould, Janet; Callis, Courtney M; Dolan, David G; Stanard, Brad; Weideman, Patricia A

    2016-08-01

    Recently, a guideline has been published by the European Medicines Agency (EMA) on setting safe limits, permitted daily exposures (PDE) [also called acceptable daily exposures (ADE)], for medicines manufactured in multi-product facilities. The ADE provides a safe exposure limit for inadvertent exposure of a drug due to cross-contamination in manufacturing. The ADE determination encompasses a standard risk assessment, requiring an understanding of the toxicological and pharmacological effects, the mechanism of action, drug compound class, and the dose-response as well as the pharmacokinetic properties of the compound. While the ADE concept has broad application in pharmaceutical safety there are also nuances and specific challenges associated with some toxicological endpoints or drug product categories. In this manuscript we discuss considerations for setting ADEs when the following specific adverse health endpoints may constitute the critical effect: genotoxicity, developmental and reproductive toxicity (DART), and immune system modulation (immunostimulation or immunosuppression), and for specific drug classes, including antibody drug conjugates (ADCs), emerging medicinal therapeutic compounds, and compounds with limited datasets. These are challenging toxicological scenarios that require a careful evaluation of all of the available information in order to establish a health-based safe level. PMID:27233924

  7. Contaminant effect endpoints in terrestrial vertebrates at and above the individual level

    USGS Publications Warehouse

    Rattner, B.A.; Cohen, J.B.; Golden, N.H.

    2000-01-01

    Use of biochemical, physiological, anatomical, reproductive and behavioral characteristics of wild terrestrial vertebrates to assess contaminant exposure and effects has become commonplace over the past 3 decades. At the level of the individual organism, response patterns have been associated with and sometimes causally linked to contaminant exposure. However, such responses at the organismal level are rarely associated with or causally linked to effects at the population level. Although the ultimate goal of ecotoxicology is the protection of populations, communities, and ecosystems, most of the existing science and regulatory legislation focus on the level of the individual. Consequently, much of this overview concentrates on contaminant effects at the organismal level, with some extrapolation to higher-level effects. In this chapter, we review the state of the science for the evaluation of biotic end-points used to assess contaminant exposure and effects at or above the level of the individual. In addition, we describe extant contaminant concentration thresholds, guidelines, or standards (toxicant criteria) in environmental matrices (e.g., water, soil, sediment, foods) that have been developed to protect wild terrestrial vertebrates. Suggestions are provided to develop and embellish the use and value of such endpoints and criteria for extrapolation of effects to higher levels of biological organization. Increasing focus on populations, communities, and ecosystems is needed to develop biologically meaningful regulatory guidelines that will protect natural resources.

  8. Syndecan-4 modulates the proliferation of neural cells and the formation of CaP axons during zebrafish embryonic neurogenesis

    PubMed Central

    Luo, Ning; Li, Hongda; Xiang, Bo; Qiao, Liangjun; He, Jiao; Ji, Yi; Liu, Yuan; Li, Siying; Lu, Ran; Li, Yu; Meng, Wentong; Wu, Yang; Xu, Hong; Mo, Xianming

    2016-01-01

    Syndecan-4 (Syn4), a single-pass transmembrane heparin sulphate proteoglycan (HSPG), plays significant role in the formation of focal adhesions and interacts with many growth factors to regulate cell migration and neural induction. Here, we show the new roles of syndecan-4(syn4) in zebrafish embryonic neurogenesis. Syn4 is broadly and dynamically expressed throughout the early stages of embryonic development. Knockdown of syn4 increases the expression of the marker genes of multiple types of neural cells. The increased expression of the marker genes is resulted from excessive proliferation of the neural cells. In addition, disrupting syn4 expression results in truncated and multiple aberrant branching of caudal primary (CaP) axons. Collectively, these data indicate that Syn4 suppresses the cellular proliferation during neurogenesis and is crucial for the formation of CaP axons during zebrafish embryogenesis. PMID:27143125

  9. Human embryonic stem cells and embryonal carcinoma cells have overlapping and distinct metabolic signatures.

    PubMed

    Abu Dawud, Raed; Schreiber, Kerstin; Schomburg, Dietmar; Adjaye, James

    2012-01-01

    While human embryonic stem cells (hESCs) and human embryonal carcinoma cells (hECCs) have been studied extensively at the levels of the genome, transcriptome, proteome and epigenome our knowledge of their corresponding metabolomes is limited. Here, we present the metabolic signatures of hESCs and hESCs obtained by untargeted gas chromatography coupled to mass spectrometry (GC-MS). Whilst some metabolites are common to both cell types, representing the self-renewal and house-keeping signatures, others were either higher (e.g., octadecenoic acid, glycerol-3-phosphate, 4-hydroxyproline) or lower (e.g., glutamic acid, mannitol, malic acid, GABA) in hESCs (H9) compared to hECCs (NTERA2), these represent cell type specific signatures. Further, our combined results of GC-MS and microarray based gene expression profiling of undifferentiated and OCT4-depleted hESCs are consistent with the Warburg effect which is increased glycolysis in embryonic cells and tumor cells in the presence of O(2) while oxidative phosphorylation (OXPHOS) is impaired or even shut down. RNAi-based OCT4 knock down mediated differentiation resulted in the activation of the poised OXPHOS machinery by expressing missing key proteins such as NDUFC1, UQCRB and COX, increase in TCA cycle activity and decreased lactate metabolism. These results shed light on the metabolite layer of pluripotent stem cells and could potentially establish novel metabolic markers of self renewal and pluripotency. PMID:22768158

  10. Human Embryonic Stem Cells and Embryonal Carcinoma Cells Have Overlapping and Distinct Metabolic Signatures

    PubMed Central

    Schomburg, Dietmar; Adjaye, James

    2012-01-01

    While human embryonic stem cells (hESCs) and human embryonal carcinoma cells (hECCs) have been studied extensively at the levels of the genome, transcriptome, proteome and epigenome our knowledge of their corresponding metabolomes is limited. Here, we present the metabolic signatures of hESCs and hESCs obtained by untargeted gas chromatography coupled to mass spectrometry (GC-MS). Whilst some metabolites are common to both cell types, representing the self-renewal and house-keeping signatures, others were either higher (e.g., octadecenoic acid, glycerol-3-phosphate, 4-hydroxyproline) or lower (e.g., glutamic acid, mannitol, malic acid, GABA) in hESCs (H9) compared to hECCs (NTERA2), these represent cell type specific signatures. Further, our combined results of GC-MS and microarray based gene expression profiling of undifferentiated and OCT4-depleted hESCs are consistent with the Warburg effect which is increased glycolysis in embryonic cells and tumor cells in the presence of O2 while oxidative phosphorylation (OXPHOS) is impaired or even shut down. RNAi-based OCT4 knock down mediated differentiation resulted in the activation of the poised OXPHOS machinery by expressing missing key proteins such as NDUFC1, UQCRB and COX, increase in TCA cycle activity and decreased lactate metabolism. These results shed light on the metabolite layer of pluripotent stem cells and could potentially establish novel metabolic markers of self renewal and pluripotency. PMID:22768158

  11. International Cartilage Repair Society (ICRS) Recommended Guidelines for Histological Endpoints for Cartilage Repair Studies in Animal Models and Clinical Trials

    PubMed Central

    Hoemann, Caroline; Kandel, Rita; Roberts, Sally; Saris, Daniel B.F.; Creemers, Laura; Mainil-Varlet, Pierre; Méthot, Stephane; Hollander, Anthony P.; Buschmann, Michael D.

    2011-01-01

    Cartilage repair strategies aim to resurface a lesion with osteochondral tissue resembling native cartilage, but a variety of repair tissues are usually observed. Histology is an important structural outcome that could serve as an interim measure of efficacy in randomized controlled clinical studies. The purpose of this article is to propose guidelines for standardized histoprocessing and unbiased evaluation of animal tissues and human biopsies. Methods were compiled from a literature review, and illustrative data were added. In animal models, treatments are usually administered to acute defects created in healthy tissues, and the entire joint can be analyzed at multiple postoperative time points. In human clinical therapy, treatments are applied to developed lesions, and biopsies are obtained, usually from a subset of patients, at a specific time point. In striving to standardize evaluation of structural endpoints in cartilage repair studies, 5 variables should be controlled: 1) location of biopsy/sample section, 2) timing of biopsy/sample recovery, 3) histoprocessing, 4) staining, and 5) blinded evaluation with a proper control group. Histological scores, quantitative histomorphometry of repair tissue thickness, percentage of tissue staining for collagens and glycosaminoglycan, polarized light microscopy for collagen fibril organization, and subchondral bone integration/structure are all relevant outcome measures that can be collected and used to assess the efficacy of novel therapeutics. Standardized histology methods could improve statistical analyses, help interpret and validate noninvasive imaging outcomes, and permit cross-comparison between studies. Currently, there are no suitable substitutes for histology in evaluating repair tissue quality and cartilaginous character. PMID:26069577

  12. UST-ID robotics: Wireless communication and minimum conductor technology, and end-point tracking technology surveys

    SciTech Connect

    Holliday, M.A.

    1993-10-01

    This report is a technology review of the current state-of-the-art in two technologies applicable to the Underground Storage Tank (UST) program at the Hanford Nuclear Reservation. The first review is of wireless and minimal conductor technologies for in-tank communications. The second review is of advanced concepts for independent tool-point tracking. This study addresses the need to provide wireless transmission media or minimum conductor technology for in-tank communications and robot control. At present, signals are conducted via contacting transmission media, i.e., cables. Replacing wires with radio frequencies or invisible light are commonplace in the communication industry. This technology will be evaluated for its applicability to the needs of robotics. Some of these options are radio signals, leaky coax, infrared, microwave, and optical fiber systems. Although optical fiber systems are contacting transmission media, they will be considered because of their ability to reduce the number of conductors. In this report we will identify, evaluate, and recommend the requirements for wireless and minimum conductor technology to replace the present cable system. The second section is a technology survey of concepts for independent end-point tracking (tracking the position of robot end effectors). The position of the end effector in current industrial robots is determined by computing that position from joint information, which is basically a problem of locating a point in three-dimensional space. Several approaches are presently being used in industrial robotics, including: stereo-triangulation with a theodolite network and electrocamera system, photogrammetry, and multiple-length measurement with laser interferometry and wires. The techniques that will be evaluated in this survey are advanced applications of the aforementioned approaches. These include laser tracking (3-D and 5-D), ultrasonic tracking, vision-guided servoing, and adaptive robotic visual tracking.

  13. Automated analysis of embryonic gene expression with cellular resolution in C. elegans

    PubMed Central

    Murray, John Isaac; Bao, Zhirong; Boyle, Thomas J.; Boeck, Max E.; Mericle, Barbara L.; Nicholas, Thomas J.; Zhao, Zhongying; Sandel, Matthew J.; Waterston, Robert H.

    2008-01-01

    We describe a system that permits the automated analysis of reporter gene expression in Caenorhabditis elegans with cellular resolution continuously during embryogenesis and demonstrate its utility by defining the expression patterns of reporters for several embryonically expressed transcription factors. The invariant cell lineage permits the automated alignment of multiple expression profiles, allowing the direct comparison of the expression of different genes' reporters. We have also used the system to monitor perturbations to normal development involving changes both in cell division timing and in cell fate. Systematic application could reveal the gene activity of each cell throughout development. PMID:18587405

  14. Juveniles exposed to embryonic corticosterone have enhanced flight performance

    PubMed Central

    Chin, Eunice H.; Love, Oliver P.; Verspoor, Jan J.; Williams, Tony D.; Rowley, Kyle; Burness, Gary

    2008-01-01

    Exposure to maternally derived glucocorticoids during embryonic development impacts offspring phenotype. Although many of these effects appear to be transiently ‘negative’, embryonic exposure to maternally derived stress hormones is hypothesized to induce preparative responses that increase survival prospects for offspring in low-quality environments; however, little is known about how maternal stress influences longer-term survival-related performance traits in free-living individuals. Using an experimental elevation of yolk corticosterone (embryonic signal of low maternal quality), we examined potential impacts of embryonic exposure to maternally derived stress on flight performance, wing loading, muscle morphology and muscle physiology in juvenile European starlings (Sturnus vulgaris). Here we report that fledglings exposed to experimentally increased corticosterone in ovo performed better during flight performance trials than control fledglings. Consistent with differences in performance, individuals exposed to elevated embryonic corticosterone fledged with lower wing loading and had heavier and more functionally mature flight muscles compared with control fledglings. Our results indicate that the positive effects on a survival-related trait in response to embryonic exposure to maternally derived stress hormones may balance some of the associated negative developmental costs that have recently been reported. Moreover, if embryonic experience is a good predictor of the quality or risk of future environments, a preparative phenotype associated with exposure to apparently negative stimuli during development may be adaptive. PMID:18842541

  15. Root length of aquatic plant, Lemna minor L., as an optimal toxicity endpoint for biomonitoring of mining effluents.

    PubMed

    Gopalapillai, Yamini; Vigneault, Bernard; Hale, Beverley A

    2014-10-01

    Lemna minor, a free-floating macrophyte, is used for biomonitoring of mine effluent quality under the Metal Mining Effluent Regulations (MMER) of the Environmental Effects Monitoring (EEM) program in Canada and is known to be sensitive to trace metals commonly discharged in mine effluents such as Ni. Environment Canada's standard toxicity testing protocol recommends frond count (FC) and dry weight (DW) as the 2 required toxicity endpoints-this is similar to other major protocols such as those by the US Environmental Protection Agency (USEPA) and the Organisation for Economic Co-operation and Development (OECD)-that both require frond growth or biomass endpoints. However, we suggest that similar to terrestrial plants, average root length (RL) of aquatic plants will be an optimal and relevant endpoint. As expected, results demonstrate that RL is the ideal endpoint based on the 3 criteria: accuracy (i.e., toxicological sensitivity to contaminant), precision (i.e., lowest variance), and ecological relevance (metal mining effluents). Roots are known to play a major role in nutrient uptake in conditions of low nutrient conditions-thus having ecological relevance to freshwater from mining regions. Root length was the most sensitive and precise endpoint in this study where water chemistry varied greatly (pH and varying concentrations of Ca, Mg, Na, K, dissolved organic carbon, and an anthropogenic organic contaminant, sodium isopropyl xanthates) to match mining effluent ranges. Although frond count was a close second, dry weight proved to be an unreliable endpoint. We conclude that toxicity testing for the floating macrophyte should require average RL measurement as a primary endpoint. PMID:25045146

  16. Ephrin-Eph signaling in embryonic tissue separation

    PubMed Central

    Fagotto, Francois; Winklbauer, Rudolf; Rohani, Nazanin

    2014-01-01

    The physical separation of the embryonic regions that give rise to the tissues and organs of multicellular organisms is a fundamental aspect of morphogenesis. Pioneer experiments by Holtfreter had shown that embryonic cells can sort based on “tissue affinities,” which have long been considered to rely on differences in cell-cell adhesion. However, vertebrate embryonic tissues also express a variety of cell surface cues, in particular ephrins and Eph receptors, and there is now firm evidence that these molecules are systematically used to induce local repulsion at contacts between different cell types, efficiently preventing mixing of adjacent cell populations. PMID:25482630

  17. Screening of nanoparticle embryotoxicity using embryonic stem cells.

    PubMed

    Campagnolo, Luisa; Fenoglio, Ivana; Massimiani, Micol; Magrini, Andrea; Pietroiusti, Antonio

    2013-01-01

    Due to the increasing use of engineered nanoparticles in many consumer products, rapid and economic tests for evaluating possible adverse effects on human health are urgently needed. In the present chapter the use of mouse embryonic stem cells as a valuable tool to in vitro screen nanoparticle toxicity on embryonic tissues is described. This in vitro method is a modification of the embryonic stem cell test, which has been widely used to screen soluble chemical compounds for their embryotoxic potential. The test offers an alternative to animal experimentation, reducing experimental costs and ethical issues. PMID:23592031

  18. Cannabinoid Receptor-2 Regulates Embryonic Hematopoietic Stem Cell Development via Prostaglandin E2 and P-Selectin Activity.

    PubMed

    Esain, Virginie; Kwan, Wanda; Carroll, Kelli J; Cortes, Mauricio; Liu, Sarah Y; Frechette, Gregory M; Sheward, Lea M V; Nissim, Sahar; Goessling, Wolfram; North, Trista E

    2015-08-01

    Cannabinoids (CB) modulate adult hematopoietic stem and progenitor cell (HSPCs) function, however, impact on the production, expansion, or migration of embryonic HSCs is currently uncharacterized. Here, using chemical and genetic approaches targeting CB-signaling in zebrafish, we show that CB receptor (CNR) 2, but not CNR1, regulates embryonic HSC development. During HSC specification in the aorta-gonad-mesonephros (AGM) region, CNR2 stimulation by AM1241 increased runx1;cmyb(+) HSPCs, through heightened proliferation, whereas CNR2 antagonism decreased HSPC number; FACS analysis and absolute HSC counts confirmed and quantified these effects. Epistatic investigations showed AM1241 significantly upregulated PGE2 synthesis in a Ptgs2-dependent manner to increase AGM HSCs. During the phases of HSC production and colonization of secondary niches, AM1241 accelerated migration to the caudal hematopoietic tissue (CHT), the site of embryonic HSC expansion, and the thymus; however these effects occurred independently of PGE2. Using a candidate approach for HSC migration and retention factors, P-selectin was identified as the functional target of CNR2 regulation. Epistatic analyses confirmed migration of HSCs into the CHT and thymus was dependent on CNR2-regulated P-selectin activity. Together, these data suggest CNR2-signaling optimizes the production, expansion, and migration of embryonic HSCs by modulating multiple downstream signaling pathways. PMID:25931248

  19. Potential surrogate endpoints for overall survival in locoregionally advanced nasopharyngeal carcinoma: an analysis of a phase III randomized trial

    PubMed Central

    Chen, Yu-Pei; Chen, Yong; Zhang, Wen-Na; Liang, Shao-Bo; Zong, Jing-Feng; Chen, Lei; Mao, Yan-Ping; Tang, Ling-Long; Li, Wen-Fei; Liu, Xu; Guo, Ying; Lin, Ai-Hua; Liu, Meng-Zhong; Sun, Ying; Ma, Jun

    2015-01-01

    The gold standard endpoint in trials of locoregionally advanced nasopharyngeal carcinoma (NPC) is overall survival (OS). Using data from a phase III randomized trial, we evaluated whether progression-free survival (PFS), failure-free survival (FFS), distant failure-free survival (D-FFS) or locoregional failure-free survival (LR-FFS) could be reliable surrogate endpoints for OS. Between July 2002 and September 2005, 316 eligible patients with stage III-IVB NPC were randomly assigned to receive either radiotherapy alone or chemoradiotherapy. 2- and 3-year PFS, FFS, D-FFS, and LR-FFS were tested as surrogate endpoints for 5-year OS using Prentice’s four criteria. The Spearman’s rank correlation coefficient was calculated to assess the strength of the associations. After a median follow-up time of 5.8 years, 2- and 3-year D-FFS and LR-FFS were not significantly different between treatment arms, in rejection of Prentice’s second criterion. Being consistent with all Prentice’s criteria, 2- and 3-year PFS and FFS were valid surrogate endpoints for 5-year OS; the rank correlation coefficient was highest (0.84) between 3-year PFS and 5-year OS. In conclusion, PFS and FFS at 2 and 3 years may be candidate surrogate endpoints for OS at 5 years; 3-year PFS may be more appropriate for early assessment of long-term survival. PMID:26219568

  20. Early Benefit Assessments in Oncology in Germany: How Can a Clinically Relevant Endpoint Not Be Relevant to Patients?

    PubMed

    Ruof, Jörg; Flückiger, Olivier; Andre, Niko

    2015-09-01

    After 4 years of early benefit assessment (EBA) in Germany, it is becoming evident that the Federal Joint Committee (FJC) frequently considers well-established clinical endpoints as not being relevant to patients. Focusing on assessments of oncology medicines, we analysed the FJC's view on primary endpoints and compared it with the approach used by regulatory authorities. Mortality data were accepted by both stakeholders. Whereas regulatory authorities accepted primary morbidity endpoints such as progression-free survival and response rates, the FJC mostly excluded these from its assessments. Health-related quality of life (HRQoL) data have been poorly reflected in the approval process; for EBAs, those data have rarely impacted on benefit ratings. We argue that agreement between regulatory authorities and the FJC is required regarding primary study endpoints that are relevant to patients, and that clarification of acceptable endpoints by the FJC, especially in the morbidity domain, has to be provided. Moreover, in order to fully acknowledge the benefit of a new medicinal product, mortality, morbidity and HRQoL should be weighted differentially, according to the condition. PMID:26286202

  1. Traditional and new composite endpoints in heart failure clinical trials: facilitating comprehensive efficacy assessments and improving trial efficiency.

    PubMed

    Anker, Stefan D; Schroeder, Stefan; Atar, Dan; Bax, Jeroen J; Ceconi, Claudio; Cowie, Martin R; Crisp, Adam; Dominjon, Fabienne; Ford, Ian; Ghofrani, Hossein-Ardeschir; Gropper, Savion; Hindricks, Gerhard; Hlatky, Mark A; Holcomb, Richard; Honarpour, Narimon; Jukema, J Wouter; Kim, Albert M; Kunz, Michael; Lefkowitz, Martin; Le Floch, Chantal; Landmesser, Ulf; McDonagh, Theresa A; McMurray, John J; Merkely, Bela; Packer, Milton; Prasad, Krishna; Revkin, James; Rosano, Giuseppe M C; Somaratne, Ransi; Stough, Wendy Gattis; Voors, Adriaan A; Ruschitzka, Frank

    2016-05-01

    Composite endpoints are commonly used as the primary measure of efficacy in heart failure clinical trials to assess the overall treatment effect and to increase the efficiency of trials. Clinical trials still must enrol large numbers of patients to accrue a sufficient number of outcome events and have adequate power to draw conclusions about the efficacy and safety of new treatments for heart failure. Additionally, the societal and health system perspectives on heart failure have raised interest in ascertaining the effects of therapy on outcomes such as repeat hospitalization and the patient's burden of disease. Thus, novel methods for using composite endpoints in clinical trials (e.g. clinical status composite endpoints, recurrent event analyses) are being applied in current and planned trials. Endpoints that measure functional status or reflect the patient experience are important but used cautiously because heart failure treatments may improve function yet have adverse effects on mortality. This paper discusses the use of traditional and new composite endpoints, identifies qualities of robust composites, and outlines opportunities for future research. PMID:27071916

  2. Overall survival should be the primary endpoint in clinical trials for advanced non-small-cell lung cancer

    PubMed Central

    Cheema, P.K.; Burkes, R.L.

    2013-01-01

    An article in a recent edition of Current Oncology explored the validation of progression-free survival (pfs) as an endpoint in clinical trials of antineoplastic agents for metastatic colorectal cancer, metastatic renal cell carcinoma, and ovarian cancer. The support for pfs as a surrogate endpoint for overall survival (os) was elucidated. As with the aforementioned tumour types, advanced non-small-cell lung cancer (nsclc) has seen a rise in active agents since the year 2000. Those agents range from improved cytotoxics such as pemetrexed, to targeted therapies such as tyrosine kinase inhibitors of the epidermal growth factor receptor and agents that target the EML4–ALK gene mutation. More recently, it has also become apparent that histology plays an important role in the response to and outcomes of treatment. With the therapeutic options for patients with advanced nsclc increasing, concerns are being raised that the efficacy of drugs measured by os may be diluted in clinical trials, thereby underestimating their true clinical benefit. That possibility, together with the need to have efficacious drugs available to patients earlier, has resulted in the search for a surrogate to the os endpoint in advanced nsclc. The present article follows up the recent article on pfs as a surrogate. Although advances in identifying pfs as a valid surrogate endpoint for os have been made in other tumour types, in advanced nsclc, such surrogacy has not been formally validated. Until it has, os should remain the primary endpoint of clinical trials in advanced nsclc. PMID:23559882

  3. [Selective embryonic or fetal reduction by surgical transvaginal ultrasonography].

    PubMed

    Delafontaine, D; Mugniot-bellamy, S; Simeon, S; Menard, M N

    1991-06-01

    The increased use of ovulation induction and of medically assisted fertilization procedures involving transfer of 3 or more ova has resulted in an increased frequency of multiple pregnancies. This paper describes 6 cases in which the number of embryos was reduced by a transvaginal transuterine route guided by sonography. 3 women with multiple pregnancies resulting from in vitro fertilization (IVF) in a fertility clinic in France and 3 patients referred to the clinic with multiple pregnancies after ovulation induction elsewhere underwent the procedure under general anesthesia in 1989-90. A needle was introduced through the vagina and the uterine wall and into the nearest gestational sac. A hypertonic solution of potassium chloride was injected into or neat the heart. The needle was withdrawn after verification that cardiac activity had ceased and that the remaining embryos were healthy. A follow-up sonography was done 24 hours later and the procedure repeated if necessary. The 3 IVF patients ranged in age from 26-37 years. The 2 triplet and 1 quadruple pregnancies were reduced to twin pregnancies and all resulted in births of healthy twins at between 36 weeks and term. The 3 patients in whom ovulation was induced ranged in age from 18-26 years. 1 had a miscarriage of undetermined etiology at 20 weeks and the other 2 pregnancies were still in progress after reduction to 2. The literature on the progress of multiple pregnancies is relatively limited. It is recognized however the multiple pregnancy increased the rate of prematurity, of low birth weight, and of intrauterine and perinatal mortality, with the risk increasing as the pregnancy order increases. It is generally advised that pregnancies of orders higher than 3 be reduced, but opinions are divided for triple pregnancies. Selective reduction represents a partial solution to the problem of multiple pregnancies, at the cost of psychological suffering for the parents and an increased risk of abortion with embryonic

  4. Probing electroweak physics for all B{yields}XM decays in the endpoint region

    SciTech Connect

    Chay, Junegone; Kim, Chul; Leibovich, Adam K.; Zupan, Jure

    2007-11-01

    Using soft-collinear effective theory we describe at leading order in 1/m{sub b} all the semi-inclusive hadronic B{yields}XM decays near the endpoint, where an energetic light meson M recoils against an inclusive jet X. Here we extend to the decays in which spectator quarks go into the jet X, and also include the decays involving {eta}, {eta}{sup '} mesons that receive additional contributions from gluonic operators. The predicted branching ratios and CP asymmetries depend on fewer hadronic parameters than the corresponding two-body B decays. This makes semi-inclusive hadronic B{yields}XM decays a powerful probe of the potential nonperturbative nature of charming penguins as well as a useful probe of new physics effects in electroweak flavor changing transitions. A comparison with B{yields}KX data from BABAR points to an enhanced charming penguin, albeit with large experimental errors.

  5. Roberge-Weiss endpoint at the physical point of Nf=2 +1 QCD

    NASA Astrophysics Data System (ADS)

    Bonati, Claudio; D'Elia, Massimo; Mariti, Marco; Mesiti, Michele; Negro, Francesco; Sanfilippo, Francesco

    2016-04-01

    We study the phase diagram of Nf=2 +1 QCD in the T -μB plane and investigate the critical point corresponding to the onset of the Roberge-Weiss transition, which is found for imaginary values of μB. We make use of stout improved staggered fermions and of the tree level Symanzik gauge action and explore four different sets of lattice spacings, corresponding to Nt=4 , 6, 8, 10, and different spatial sizes, in order to assess the universality class of the critical point. The continuum extrapolated value of the endpoint temperature is found to be TRW=208 (5 ) MeV , i.e. TRW/Tc˜1.34 (7 ) , where Tc is the chiral pseudocritical temperature at zero chemical potential, while our finite size scaling analysis, performed on Nt=4 and Nt=6 lattices, provides evidence for a critical point in the 3D Ising universality class.

  6. Social functioning: should it become an endpoint in trials of antidepressants?

    PubMed

    Bech, Per

    2005-01-01

    DSM-IV has recommended use of the Social and Occupational Functioning Scale (SOFAS) as a clinician-rated global assessment scale for measuring social functioning; this scale is analogous to the Clinical Global Impression (CGI) scale traditionally used as a secondary outcome measure in patients with depressive symptoms. However, we believe that health-related quality of life is the most appropriate indicator of social functioning when considering this dimension as an endpoint in clinical trials of antidepressants. As health-related quality of life is a purely subjective measure, patient-rated questionnaires have been found to be most important in this context. In this respect, the Sheehan Disability Scale has been recommended as the most relevant global self-reported assessment of social functioning in trials of antidepressants.A review of questionnaires found that the three most frequently used scales selectively directed at obtaining information about social functioning in trials of antidepressants are the Social Adjustment Scale - Self Report (SAS-SR), the Social Adaptation Self-Evaluation Scale (SASS) and the Short-Form Health Survey (SF-36). However, the number of placebo-controlled trials of antidepressants that have used these scales is still too limited to allow comparisons in terms of responsiveness.Health-related quality of life includes dimensions other than social functioning, e.g. physical health and mental health (including both cognitive and affective problems). The SF-36 includes subscales relating to physical and mental health, which, like the social functioning subscales, are measured in terms of degrees of well being. Another quality-of-life questionnaire, the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q), covers social, mental and physical problems, in this case measured in terms of degrees of satisfaction. Recently, the Q-LES-Q has been reduced from a comprehensive scale including 60-92 items to a brief version including 15

  7. Patient-Reported Outcome Assessments as Endpoints in Studies in Infectious Diseases.

    PubMed

    Powers, John H; Howard, Kellee; Saretsky, Todd; Clifford, Sarah; Hoffmann, Steve; Llorens, Lily; Talbot, George

    2016-08-15

    The goal of administering medical interventions is to help patients live longer or live better. In keeping with this goal, there has been increasing interest in taking the "voice" of the patient into account during the development process, specifically in the evaluation of treatment benefits of medical interventions, and use of patient-centered outcome data to justify reimbursement. Patient-reported outcomes (PROs) are outcome assessments (OAs) used to define endpoints that can provide direct evidence of treatment benefit on how patients feel or function. When PROs are appropriately developed, they can increase the efficiency and clinical relevance of clinical trials. Several PROs have been developed for OA in specific infectious diseases indications, and more are under development. PROs also hold promise for use in evaluating adherence, adverse effects, satisfaction with care, and routine clinical practice. PMID:27481954

  8. Comparison endpoint study of process plasma and secondary electron beam exciter optical emission spectroscopy

    SciTech Connect

    Stephan Thamban, P. L.; Yun, Stuart; Padron-Wells, Gabriel; Hosch, Jimmy W.; Goeckner, Matthew J.

    2012-11-15

    Traditionally process plasmas are often studied and monitored by optical emission spectroscopy. Here, the authors compare experimental measurements from a secondary electron beam excitation and direct process plasma excitation to discuss and illustrate its distinctiveness in the study of process plasmas. They present results that show excitations of etch process effluents in a SF{sub 6} discharge and endpoint detection capabilities in dark plasma process conditions. In SF{sub 6} discharges, a band around 300 nm, not visible in process emission, is observed and it can serve as a good indicator of etch product emission during polysilicon etches. Based on prior work reported in literature the authors believe this band is due to SiF{sub 4} gas phase species.

  9. Embryonic testicular regression sequence: A part of the clinical spectrum of 46,XY gonadal dysgenesis

    SciTech Connect

    Marcantonio, S.M.; Fechner, P.Y.; Migeon, C.J.; Perlman, E.J.; Berkovitz, G.D.

    1994-01-01

    The authors report on a group of 9 subjects who had a 46,XY karyotype, ambiguous genitalia, abnormalities of sexual duct formation, and lack of gonadal tissue on one or both sides. This is sometimes referred to as {open_quotes}embryonic testicular regression.{close_quotes} Previous investigators have suggested that this condition results from loss of testes at a critical stage in development. The authors examined the possibility that embryonic testicular regression is part of the clinical spectrum of 46,XY gonadal dysgenesis. Four subjects totally lacked gonadal tissue, three of them having ambiguous genitalia, and one a micropenis. The development of incongruous sexual ducts (presence of Muellerian ducts in the subject with micropenis, and absence of Muellerian and Wolffian ducts in two subjects with ambiguous genitalia) suggests that the embryonic gonads were intrinsically functionally abnormal before their disappearance. Five subjects had unilateral gonadal tissue, ambiguous genitalia, and a mix of Wolffian and Muellerian structures. The development of incongruous sexual ducts in 3 of them, the presence of ambiguous external genitalia in 5, and the presence of abnormal gonadal histology in 2 patients all indicate an underlying abnormality of gonadal differentiation in these subjects. The occurrence of testicular regression in several subjects in the family of one patient suggests a genetic basis for the condition. The presence of multiple congenital anomalies in other subjects in the study suggests either a mutation in a single gene that functions in several developmental pathways, or a defect of multiple genes that might be the result of a chromosome deletion. The sex-determining region Y (SRY) gene was sequenced in five subjects and was normal in all of them, suggesting that the underlying genetic abnormality in these subjects is located in one of several genes that function subsequent to SRY in the early stages of testis differentiation. 37 refs., 2 tabs.

  10. Sertad1 encodes a novel transcriptional co-activator of SMAD1 in mouse embryonic hearts

    SciTech Connect

    Peng, Yin; Zhao, Shaomin; Song, Langying; Wang, Manyuan; Jiao, Kai

    2013-11-29

    Highlights: •SERTAD1 interacts with SMAD1. •Sertad1 is expressed in mouse embryonic hearts. •SERTAD1 is localized in both cytoplasm and nucleus of cardiomyocytes. •SERTAD1 enhances expression of BMP target cardiogenic genes as a SMAD1 co-activator. -- Abstract: Despite considerable advances in surgical repairing procedures, congenital heart diseases (CHDs) remain the leading noninfectious cause of infant morbidity and mortality. Understanding the molecular/genetic mechanisms underlying normal cardiogenesis will provide essential information for the development of novel diagnostic and therapeutic strategies against CHDs. BMP signaling plays complex roles in multiple cardiogenic processes in mammals. SMAD1 is a canonical nuclear mediator of BMP signaling, the activity of which is critically regulated through its interaction partners. We screened a mouse embryonic heart yeast two-hybrid library using Smad1 as bait and identified SERTAD1 as a novel interaction partner of SMAD1. SERTAD1 contains multiple potential functional domains, including two partially overlapping transactivation domains at the C terminus. The SERTAD1-SMAD1 interaction in vitro and in mammalian cells was further confirmed through biochemical assays. The expression of Sertad1 in developing hearts was demonstrated using RT-PCR, western blotting and in situ hybridization analyses. We also showed that SERTAD1 was localized in both the cytoplasm and nucleus of immortalized cardiomyocytes and primary embryonic cardiomyocyte cultures. The overexpression of SERTAD1 in cardiomyocytes not only enhanced the activity of two BMP reporters in a dose-dependent manner but also increased the expression of several known BMP/SMAD regulatory targets. Therefore, these data suggest that SERTAD1 acts as a SMAD1 transcriptional co-activator to promote the expression of BMP target genes during mouse cardiogenesis.

  11. Correlation of Hip Fracture with Other Fracture Types: Toward a Rational Composite Hip Fracture Endpoint

    PubMed Central

    Colón-Emeric, Cathleen; Pieper, Carl F.; Grubber, Janet; Van Scoyoc, Lynn; Schnell, Merritt L; Van Houtven, Courtney Harold; Pearson, Megan; Lafleur, Joanne; Lyles, Kenneth W.; Adler, Robert A.

    2016-01-01

    Purpose With ethical requirements to the enrollment of lower risk subjects, osteoporosis trials are underpowered to detect reduction in hip fractures. Different skeletal sites have different levels of fracture risk and response to treatment. We sought to identify fracture sites which cluster with hip fracture at higher than expected frequency; if these sites respond to treatment similarly, then a composite fracture endpoint could provide a better estimate of hip fracture reduction. Methods Cohort study using Veterans Affairs and Medicare administrative data. Male Veterans (n=5,036,536) aged 50-99 years receiving VA primary care between1999-2009 were included. Fractures were ascertained using ICD9 and CPT codes and classified by skeletal site. Pearson correlation coefficients, logistic regression and kappa statistics, were used to describe the correlation between each fracture type and hip fracture within individuals, without regards to the timing of the events. Results 595,579 (11.8%) men suffered 1 or more fractures and 179,597 (3.6%) suffered 2 or more fractures during the time under study. Of those with one or more fractures, rib was the most common site (29%), followed by spine (22%), hip (21%) and femur (20%). The fracture types most highly correlated with hip fracture were pelvic/acetabular (Pearson correlation coefficient 0.25, p<0.0001), femur (0.15, p<0.0001), and shoulder (0.11, p<0.0001). Conclusions Pelvic, acetabular, femur, and shoulder fractures cluster with hip fractures within individuals at greater than expected frequency. If we observe similar treatment risk reductions within that cluster, subsequent trials could consider use of a composite endpoint to better estimate hip fracture risk. PMID:26151123

  12. A modular planar robotic manipulandum with end-point torque control.

    PubMed

    Howard, Ian S; Ingram, James N; Wolpert, Daniel M

    2009-07-30

    Robotic manipulanda are extensively used in investigation of the motor control of human arm movements. They permit the application of translational forces to the arm based on its state and can be used to probe issues ranging from mechanisms of neural control to biomechanics. However, most current designs are optimized for studying either motor learning or stiffness. Even fewer include end-point torque control which is important for the simulation of objects and the study of tool use. Here we describe a modular, general purpose, two-dimensional planar manipulandum (vBOT) primarily optimized for dynamic learning paradigms. It employs a carbon fibre arm arranged as a parallelogram which is driven by motors via timing pulleys. The design minimizes the intrinsic dynamics of the manipulandum without active compensation. A novel variant of the design (WristBOT) can apply torques at the handle using an add-on cable drive mechanism. In a second variant (StiffBOT) a more rigid arm can be substituted and zero backlash belts can be used, making the StiffBOT more suitable for the study of stiffness. The three variants can be used with custom built display rigs, mounting, and air tables. We investigated the performance of the vBOT and its variants in terms of effective end-point mass, viscosity and stiffness. Finally we present an object manipulation task using the WristBOT. This demonstrates that subjects can perceive the orientation of the principal axis of an object based on haptic feedback arising from its rotational dynamics. PMID:19450621

  13. Repetitive arm motion-induced fatigue affects shoulder but not endpoint position sense.

    PubMed

    Emery, Kim; Côté, Julie N

    2012-02-01

    Neck/shoulder pain has previously been linked to repetitive work and muscle fatigue. We have shown that asymptomatic people performing repetitive upper limb tasks display signs of shoulder fatigue and of whole-body compensatory strategies. However, the role played by the proprioceptive system in the production of these compensatory strategies has not been studied. A group of asymptomatic adults (n = 18) performed a repetitive pointing task at shoulder height to fatigue. Before and after fatigue, they performed two position sense tasks, eyes closed: a single-joint task where they abducted their shoulder to the perceived horizontal and a multi-joint task, where they stood and placed their finger at the perceived location of a target in front of them at shoulder height. After fatigue, subjects made larger shoulder errors by raising their elbow higher above the horizontal (~ +1.3 cm) than before fatigue; however, their finger position accuracy was not changed, despite all subjects performing the movement in less time (~ -0.18 s) while fatigued. There were no gender differences in shoulder or finger position accuracy before or after fatigue; however, there were gender differences in the perceived finger-target location and in the temporal characteristics of the finger movement toward the target. Results suggest that healthy individuals are able to develop strategies to compensate for fatigue-induced deficits at one joint to maintain the endpoint accuracy of a multi-joint task constant. Gender differences in movement strategies and perception of endpoint location may play parts in the previously reported gender differences in work-related neck/shoulder symptoms. PMID:22124803

  14. Predictors of Long‐term Clinical Endpoints in Patients With Refractory Angina

    PubMed Central

    Povsic, Thomas J.; Broderick, Samuel; Anstrom, Kevin J.; Shaw, Linda K.; Ohman, E. Magnus; Eisenstein, Eric L.; Smith, Peter K.; Alexander, John H.

    2015-01-01

    Background Clinical outcomes in patients with refractory angina (RA) are poorly characterized and variably described. Using the Duke Database for Cardiovascular Disease (DDCD), we explored characteristics that drive clinical endpoints in patients with class II to IV angina stabilized on medical therapy. Methods and Results We explored clinical endpoints and associated costs of patients who underwent catheterization at Duke University Medical Center from 1997 to 2010 for evaluation of coronary artery disease (CAD) and were found to have advanced CAD ineligible for additional revascularization, and were clinically stable for a minimum of 60 days. Of 77 257 cardiac catheterizations performed, 1908 patients met entry criteria. The 3‐year incidence of death; cardiac rehospitalization; and a composite of death, myocardial infarction, stroke, cardiac rehospitalization, and revascularization were 13.0%, 43.5%, and 52.2%, respectively. Predictors of mortality included age, ejection fraction (EF), low body mass index, multivessel CAD, low heart rate, diabetes, diastolic blood pressure, history of coronary artery bypass graft surgery, cigarette smoking, history of congestive heart failure (CHF), and race. Multivessel CAD, EF<45%, and history of CHF increased risk of mortality; angina class and prior revascularization did not. Total rehospitalization costs over a 3‐year period per patient were $10 185 (95% CI 8458, 11912) in 2012 US dollars. Conclusions Clinically stable patients with RA who are medically managed have a modest mortality, but a high incidence of hospitalization and resource use over 3 years. These findings point to the need for novel therapies aimed at symptom mitigation in this population and their potential impact on health care utilization and costs. PMID:25637344

  15. Toward early safety alert endpoints: exploring biomarkers suggestive of microbicide failure.

    PubMed

    Mauck, Christine K; Lai, Jaim Jou; Weiner, Debra H; Chandra, Neelima; Fichorova, Raina N; Dezzutti, Charlene S; Hillier, Sharon L; Archer, David F; Creinin, Mitchell D; Schwartz, Jill L; Callahan, Marianne M; Doncel, Gustavo F

    2013-11-01

    Several microbicides, including nonoxynol-9 (N-9) and cellulose sulfate (CS), looked promising during early trials but failed in efficacy trials. We aimed to identify Phase I mucosal safety endpoints that might explain that failure. In a blinded, randomized, parallel trial, 60 healthy premenopausal sexually abstinent women applied Universal HEC placebo, 6% CS or 4% N-9 gel twice daily for 13½ days. Endpoints included immune biomarkers in cervicovaginal lavage (CVL) and endocervical cytobrushes, inflammatory infiltrates in vaginal biopsies, epithelial integrity by naked eye, colposcopy, and histology, CVL anti-HIV activity, vaginal microflora, pH, and adverse events. Twenty women enrolled per group. Soluble/cellular markers were similar with CS and placebo, except secretory leukocyte protease inhibitor (SLPI) levels decreased in CVL, and CD3(+) and CD45(+) cells increased in biopsies after CS use. Increases in interleukin (IL)-8, IL-1, IL-1RA, and myeloperoxidase (MPO) and decreases in SLPI were significant with N-9. CVL anti-HIV activity was significantly higher during CS use compared to N-9 or placebo. CS users tended to have a higher prevalence of intermediate Nugent score, Escherichia coli, and Enterococcus and fewer gram-negative rods. Most Nugent scores diagnostic for bacterial vaginosis were in N-9 users. All cases of histological inflammation or deep epithelial disruption occurred in N-9 users. While the surfactant N-9 showed obvious biochemical and histological signs of inflammation, more subtle changes, including depression of SLPI, tissue influx of CD45(+) and CD3(+) cells, and subclinical microflora shifts were associated with CS use and may help to explain the clinical failure of nonsurfactant microbicides. PMID:23885658

  16. Endpoints for therapeutic interventions in faecal incontinence: small step or game changer.

    PubMed

    Rao, S S C

    2016-08-01

    Faecal incontinence (FI) is common and its pathophysiology and treatments continue to evolve. However, a standard measure(s) for assessing its clinical outcome has been elusive. Consequently, over 100 measures and scoring systems, each with intrinsic biases have been reported. These include adequate relief or global satisfaction, ≥50% reduction in episodes or days without FI, quality of life (QOL), FI severity scales and composite indices. Earlier scales relied on the frequency and type of solid, liquid or flatus incontinence and effects on life style whereas newer scales have incorporated urgency, use of pads, antidiarrhoeals and amount of leakage, using prospective daily stool diaries or retrospective weekly or single point assessments. Such a plethora of measures have negatively impacted the assessment and outcome of clinical trials, and have made comparisons difficult. So, how does one sort out the grain from the chaff? In a provocative, post-hoc analysis published in this issue, the minimal clinically important difference, i.e. the smallest change detected by an instrument that is associated with a clinically meaningful change was used to assess FI endpoint. Based on this a ≥50% reduction in FI episodes is recommended as a clinically meaningful outcome measure when assessed by prospective stool diary, and it correlates with symptoms and severity. However, this requires further validation in multi-centre, longer duration and therapeutically effective clinical trial(s). Simultaneous assessment of coping strategies, QOL and psychosocial domains can provide further insights regarding the overall impact of treatments. This mini-review discusses the advances and controversies in defining meaningful FI endpoints. PMID:27440495

  17. Establishment of Early Endpoints in Mouse Total-Body Irradiation Model.

    PubMed

    Koch, Amory; Gulani, Jatinder; King, Gregory; Hieber, Kevin; Chappell, Mark; Ossetrova, Natalia

    2016-01-01

    Acute radiation sickness (ARS) following exposure to ionizing irradiation is characterized by radiation-induced multiorgan dysfunction/failure that refers to progressive dysfunction of two or more organ systems, the etiological agent being radiation damage to cells and tissues over time. Radiation sensitivity data on humans and animals has made it possible to describe the signs associated with ARS. A mouse model of total-body irradiation (TBI) has previously been developed that represents the likely scenario of exposure in the human population. Herein, we present the Mouse Intervention Scoring System (MISS) developed at the Veterinary Sciences Department (VSD) of the Armed Forces Radiobiology Research Institute (AFRRI) to identify moribund mice and decrease the numbers of mice found dead, which is therefore a more humane refinement to death as the endpoint. Survival rates were compared to changes in body weights and temperatures in the mouse (CD2F1 male) TBI model (6-14 Gy, 60Co γ-rays at 0.6 Gy min-1), which informed improvements to the Scoring System. Individual tracking of animals via implanted microchips allowed for assessment of criteria based on individuals rather than by group averages. From a total of 132 mice (92 irradiated), 51 mice were euthanized versus only four mice that were found dead (7% of non-survivors). In this case, all four mice were found dead after overnight periods between observations. Weight loss alone was indicative of imminent succumbing to radiation injury, however mice did not always become moribund within 24 hours while having weight loss >30%. Only one survivor had a weight loss of greater than 30%. Temperature significantly dropped only 2-4 days before death/euthanasia in 10 and 14 Gy animals. The score system demonstrates a significant refinement as compared to using subjective assessment of morbidity or death as the endpoint for these survival studies. PMID:27579862

  18. Use of sublethal endpoints in sediment toxicity tests with the amphipod Hyalella azteca

    USGS Publications Warehouse

    Ingersoll, C.G.; Brunson, E.L.; Dwyer, F.J.; Hardesty, D.K.; Kemble, N.E.

    1998-01-01

    Short-term sediment toxicity tests that only measure effects on survival can be used to identify high levels of contamination but may not be able to identify marginally contaminated sediments. The objective of the present study was to develop a method for determining the potential sublethal effects of contaminants associated with sediment on the amphipod Hyalella azteca (e.g., reproduction). Exposures to sediment were started with 7- to 8-d-old amphipods. On day 28, amphipods were isolated from the sediment and placed in water-only chambers where reproduction was measured on day 35 and 42. Typically, amphipods were first in amplexus at about day 21 to 28 with release of the first brood between day 28 to 42. Endpoints measured included survival (day 28, 35, and 42), growth (as length and weight on day 28 and 42), and reproduction (number of young/female produced from day 28 to 42). This method was used to evaluate a formulated sediment and field-collected sediments with low to moderate concentrations of contaminants. Survival of amphipods in these sediments was typically >85% after the 28-d sediment exposures and the 14-d holding period in water to measure reproduction. Reproduction was more variable than growth; hence, more replicates might be needed to establish statistical differences among treatments. Previous studies have demonstrated that growth of H. azteca in sediment tests often provides unique information that can be used to discriminate toxic effects of exposure to contaminants. Either length or weight can be measured in sediment tests with H. azteca. However, additional statistical options are available if length is measured on individual amphipods, such as nested analysis of variance that can account for variance in length within replicates. Ongoing water-only studies testing select contaminants will provide additional data on the relative sensitivity and variability of sublethal endpoints in toxicity tests with H. azteca.

  19. Different damping responses explain vertical endpoint error differences between visual conditions.

    PubMed

    Hondzinski, Jan M; Soebbing, Chelsea M; French, Allyson E; Winges, Sara A

    2016-06-01

    Upright people making goal-directed movements in dark environments often vertically undershoot remembered target locations when compared to performances in illuminated environments. In this study, we wanted to determine whether influences of the gravitational pull and/or type of muscle activation could explain differences in vertical endpoint precision between movements to visually remembered target locations with and without allocentric cues available. We also used a simple damping model for movement trajectories to describe potential differences in behavior between visual conditions. Subjects performed straight arm pointing movements to REAL target locations or remembered target locations in darkness (DARK) or normal room lighting (LIGHT). Performances were made from UPRIGHT and INVERTED (upside down) body orientations. Starting arm position (UP by the ear; DOWN on the thigh) also varied so that eccentric or concentric muscle contractions for arm flexion or extension movements occurred primarily along the earth-fixed vertical either with or against the gravitational pull. Effects of visual condition (LIGHT, DARK), body orientation (UPRIGHT, INVERTED), starting arm position (UP, DOWN), and target level (Near, Middle, Far) on elevation endpoint errors revealed that subject's errors in the DARK were more negative than those in the LIGHT. Errors correlated well with movement displacement to reveal the common vertical undershooting bias in darkness exacerbated by inverting the body or requiring greater movement excursions. Although influences of gravitational pull and muscle activation type could not explain differences between visual conditions, modeling revealed critically damped behavior in the DARK and under-damped behavior in the LIGHT to indicate muscle energy dissipation without vision. PMID:26821319

  20. Preparation of embryonic retinal explants to study CNS neurite growth.

    PubMed

    Hanea, Sonia T; Shanmugalingam, Ushananthini; Fournier, Alyson E; Smith, Patrice D

    2016-05-01

    This protocol outlines the preparation of embryonic mouse retinal explants, which provides an effective technique to analyze neurite outgrowth in central nervous system (CNS) neurons. This validated ex vivo system, which displays limited neuronal death, is highly reproducible and particularly amenable to manipulation. Our previously published studies involving embryonic chick or adult mouse retinal explants were instrumental in the preparation of this protocol; aspects of these previous techniques were combined, adopted and optimized. This protocol thus permits more efficient analysis of neurite growth. Briefly, the retina is dissected from the embryonic mouse eye using precise techniques that take into account the small size of the embryonic eye. The approach applied ensures that the retinal ganglion cell (RGC) layer faces the adhesion substrate on coated cover slips. Neurite growth is clear, well-delineated and readily quantifiable. These retinal explants can therefore be used to examine the neurite growth effects elicited by potential therapeutic agents. PMID:27072342

  1. Improved Oocyte Isolation and Embryonic Development of Outbred Deer Mice

    PubMed Central

    Kyu Choi, Jung; He, Xiaoming

    2015-01-01

    In this study, we improved the protocol for isolating cumulus-oocyte complexes (COCs) from the outbred deer mice by using only one hormone (instead of the widely used combination of two hormones) with reduced dose. Moreover, we identified that significantly more metaphase II (MII) oocytes could be obtained by supplementing epidermal growth factor (EGF) and leukemia inhibition factor (LIF) into the previously established medium for in vitro maturation (IVM) of the COCs. Furthermore, we overcame the major challenge of two-cell block during embryonic development of deer mice after either in vitro fertilization (IVF) or parthenogenetic activation (PA) of the MII oocytes, by culturing the two-cell stage embryos on the feeder layer of inactivated mouse embryonic fibroblasts (MEFs) in the medium of mouse embryonic stem cells. Collectively, this work represents a major step forward in using deer mice as an outbred animal model for biomedical research on reproduction and early embryonic development. PMID:26184014

  2. Probing Embryonic Stem Cell Autocrine and Paracrine Signaling Using Microfluidics

    NASA Astrophysics Data System (ADS)

    Przybyla, Laralynne; Voldman, Joel

    2012-07-01

    Although stem cell fate is traditionally manipulated by exogenously altering the cells' extracellular signaling environment, the endogenous autocrine and paracrine signals produced by the cells also contribute to their two essential processes: self-renewal and differentiation. Autocrine and/or paracrine signals are fundamental to both embryonic stem cell self-renewal and early embryonic development, but the nature and contributions of these signals are often difficult to fully define using conventional methods. Microfluidic techniques have been used to explore the effects of cell-secreted signals by controlling cell organization or by providing precise control over the spatial and temporal cellular microenvironment. Here we review how such techniques have begun to be adapted for use with embryonic stem cells, and we illustrate how many remaining questions in embryonic stem cell biology could be addressed using microfluidic technologies.

  3. A logrank test-based method for sizing clinical trials with two co-primary time-to-event endpoints.

    PubMed

    Sugimoto, Tomoyuki; Sozu, Takashi; Hamasaki, Toshimitsu; Evans, Scott R

    2013-07-01

    We discuss sample size determination for clinical trials evaluating the joint effects of an intervention on two potentially correlated co-primary time-to-event endpoints. For illustration, we consider the most common case, a comparison of two randomized groups, and use typical copula families to model the bivariate endpoints. A correlation structure of the bivariate logrank statistic is specified to account for the correlation among the endpoints, although the between-group comparison is performed using the univariate logrank statistic. We propose methods to calculate the required sample size to compare the two groups and evaluate the performance of the methods and the behavior of required sample sizes via simulation. PMID:23307913

  4. Initial experiments on the end-point control of a 2-DOF long-reach elastic manipulator

    NASA Astrophysics Data System (ADS)

    Schmitz, Eric; Ramey, Madison

    1992-03-01

    To support the study of dynamics and control for long-reach, space-based manipulators, an experimental planar manipulator has been developed. The arm has a 15 ft reach with flexible links at the shoulder and elbow joints. The arm's equations of motion are derived with the aid of TREETOPS, a multibody dynamics analysis program. The resulting model is validated against experimental data. To serve as a base line for future work, two classically designed controllers have been implemented. One relies on sensors collocated with the joint actuators, while the other uses an end-point sensor measuring Cartesian displacements. Comparison of the controllers' experimental closed-loop responses demonstrate the performance improvements achievable using end-point position feedback; most notable is the more than two fold increase in control bandwidth. Experimental and simulation results also demonstrate the end-point controller's improved `Cartesian impedance.'

  5. Human Embryonic Stem Cells and Cardiac Repair

    PubMed Central

    Zhu, Wei-Zhong; Hauch, Kip; Xu, Chunhui; Laflamme, Michael A.

    2008-01-01

    The muscle lost after a myocardial infarction is replaced with non-contractile scar tissue, often initiating heart failure. Whole-organ cardiac transplantation is the only currently available clinical means of replacing the lost muscle, but this option is limited by the inadequate supply of donor hearts. Thus, cell-based cardiac repair has attracted considerable interest as an alternative means of ameliorating cardiac injury. Because of their tremendous capacity for expansion and unquestioned cardiac potential, pluripotent human embryonic stem cells (hESCs) represent an attractive candidate cell source for obtaining cardiomyocytes and other useful mesenchymal cell types for such therapies. hESC-derived cardiomyocytes (hESC-CMs) exhibit a committed cardiac phenotype and robust proliferative capacity, and recent testing in rodent infarct models indicates that they can partially remuscularize injured hearts and improve contractile function. Although the latter successes give good reason for optimism, considerable challenges remain to the successful application of hESCs to cardiac repair, including the need for preparations of high cardiac purity, improved methods of delivery, and approaches to overcome immune rejection and other causes of graft cell death. This review will describe the phenotype of hESC-CMs and preclinical experience with these cells and will consider strategies to overcoming the aforementioned challenges. PMID:18657407

  6. Transcriptional profiling of regenerating embryonic mouse hearts.

    PubMed

    Magarin, Manuela; Schulz, Herbert; Thierfelder, Ludwig; Drenckhahn, Jörg-Detlef

    2016-09-01

    The postnatal mammalian heart is considered a terminally differentiated organ unable to efficiently regenerate after injury. In contrast, we have recently shown a remarkable regenerative capacity of the prenatal heart using myocardial tissue mosaicism for mitochondrial dysfunction in mice. This model is based on inactivation of the X-linked gene encoding holocytochrome c synthase (Hccs) specifically in the developing heart. Loss of HCCS activity results in respiratory chain dysfunction, disturbed cardiomyocyte differentiation and reduced cell cycle activity. The Hccs gene is subjected to X chromosome inactivation, such that in females heterozygous for the heart conditional Hccs knockout approximately 50% of cardiac cells keep the defective X chromosome active and develop mitochondrial dysfunction while the other 50% remain healthy. During heart development the contribution of HCCS deficient cells to the cardiac tissue decreases from 50% at mid-gestation to 10% at birth. This regeneration of the prenatal heart is mediated by increased proliferation of the healthy cardiac cell population, which compensates for the defective cells allowing the formation of a fully functional heart by birth. Here we performed microarray RNA expression analyses on 13.5 dpc control and heterozygous Hccs knockout hearts to identify molecular mechanisms that drive embryonic heart regeneration. Array data have been deposited in the Gene Expression Omnibus (GEO) database under accession number GSE72054. PMID:27583204

  7. Embryonic development of the emu, Dromaius novaehollandiae.

    PubMed

    Nagai, Hiroki; Mak, Siu-Shan; Weng, Wei; Nakaya, Yukiko; Ladher, Raj; Sheng, Guojun

    2011-01-01

    The chick, Gallus gallus, is the traditional model in avian developmental studies. Data on other bird species are scarce. Here, we present a comparative study of the embryonic development of the chick and the emu Dromaius novaehollandiae, a member of Paleognathae, which also includes the ostrich, rhea, tinamou, kiwi, and cassowary. Emu embryos ranging from Hamburger and Hamilton (HH) equivalent stages 1 to 43 were collected and their gross morphology analyzed. Its early development was studied in detail with time-lapse imaging and molecular techniques. Emu embryos in general take 2-3 times longer incubation time to reach equivalent chicken stages, requiring 1 day for HH2, 2.5 days for HH4, 7 days for limb bud initiation, 23 days for feather germ appearance, and approximately 50-56 days for hatching. Chordin gene expression is similar in emu and chick embryos, and emu Brachyury is not expressed until HH3. Circulation is established at approximately the 27- to 30-somite stage. Forelimb buds are formed and patterned initially, but their growth is severely retarded. The size difference between an emu and a chick embryo only becomes apparent after limb bud formation. Overall, emu and chick embryogenesis proceeds through similar stages, but developmental heterochrony between these two species is widely observed. PMID:21181941

  8. Genetic Manipulation of Human Embryonic Stem Cells.

    PubMed

    Eiges, Rachel

    2016-01-01

    One of the great advantages of embryonic stem (ES) cells over other cell types is their accessibility to genetic manipulation. They can easily undergo genetic modifications while remaining pluripotent, and can be selectively propagated, allowing the clonal expansion of genetically altered cells in culture. Since the first isolation of ES cells in mice, many effective techniques have been developed for gene delivery and manipulation of ES cells. These include transfection, electroporation, and infection protocols, as well as different approaches for inserting, deleting, or changing the expression of genes. These methods proved to be extremely useful in mouse ES cells, for monitoring and directing differentiation, discovering unknown genes, and studying their function, and are now being extensively implemented in human ES cells (HESCs). This chapter describes the different approaches and methodologies that have been applied for the genetic manipulation of HESCs and their applications. Detailed protocols for generating clones of genetically modified HESCs by transfection, electroporation, and infection will be described, with special emphasis on the important technical details that are required for this purpose. All protocols are equally effective in human-induced pluripotent stem (iPS) cells. PMID:25520283

  9. An Evaluation of Culture Results during Treatment for Tuberculosis as Surrogate Endpoints for Treatment Failure and Relapse

    PubMed Central

    Phillips, Patrick P. J.; Fielding, Katherine; Nunn, Andrew J.

    2013-01-01

    It is widely acknowledged that new regimens are urgently needed for the treatment of tuberculosis. The primary endpoint in the Phase III trials is a composite outcome of failure at the end of treatment or relapse after stopping treatment. Such trials are usually both long and expensive. Valid surrogate endpoints measured during or at the end of treatment could dramatically reduce both the time and cost of assessing the effectiveness of new regimens. The objective of this study was to evaluate sputum culture results on solid media during treatment as surrogate endpoints for poor outcome. Data were obtained from twelve randomised controlled trials conducted by the British Medical Research Council in the 1970s and 80s in East Africa and East Asia, consisting of 6974 participants and 49 different treatment regimens. The month two culture result was shown to be a poor surrogate in East Africa but a good surrogate in Hong Kong. In contrast, the month three culture was a good surrogate in trials conducted in East Africa but not in Hong Kong. As well as differences in location, ethnicity and probable strain of Mycobacteria tuberculosis, Hong Kong trials more often evaluated regimens with rifampicin throughout and intermittent regimens, and patients in East African trials more often presented with extensive cavitation and were slower to convert to culture negative during treatment. An endpoint that is a summary measure of the longitudinal profile of culture results over time or that is able to detect the presence of M. tuberculosis later in treatment is more likely to be a better endpoint for a phase II trial than a culture result at a single time point and may prove to be an acceptable surrogate. More data are needed before any endpoint can be used as a surrogate in a confirmatory phase III trial. PMID:23667677

  10. Standardized endpoint definitions for transcatheter aortic valve implantation clinical trials: a consensus report from the Valve Academic Research Consortium†

    PubMed Central

    Leon, Martin B.; Piazza, Nicolo; Nikolsky, Eugenia; Blackstone, Eugene H.; Cutlip, Donald E.; Kappetein, Arie Pieter; Krucoff, Mitchell W.; Mack, Michael; Mehran, Roxana; Miller, Craig; Morel, Marie-angèle; Petersen, John; Popma, Jeffrey J.; Takkenberg, Johanna J.M.; Vahanian, Alec; van Es, Gerrit-Anne; Vranckx, Pascal; Webb, John G.; Windecker, Stephan; Serruys, Patrick W.

    2011-01-01

    Objectives To propose standardized consensus definitions for important clinical endpoints in transcatheter aortic valve implantation (TAVI), investigations in an effort to improve the quality of clinical research and to enable meaningful comparisons between clinical trials. To make these consensus definitions accessible to all stakeholders in TAVI clinical research through a peer reviewed publication, on behalf of the public health. Background Transcatheter aortic valve implantation may provide a worthwhile less invasive treatment in many patients with severe aortic stenosis and since its introduction to the medical community in 2002, there has been an explosive growth in procedures. The integration of TAVI into daily clinical practice should be guided by academic activities, which requires a harmonized and structured process for data collection, interpretation, and reporting during well-conducted clinical trials. Methods and results The Valve Academic Research Consortium established an independent collaboration between Academic Research organizations and specialty societies (cardiology and cardiac surgery) in the USA and Europe. Two meetings, in San Francisco, California (September 2009) and in Amsterdam, the Netherlands (December 2009), including key physician experts, and representatives from the US Food and Drug Administration (FDA) and device manufacturers, were focused on creating consistent endpoint definitions and consensus recommendations for implementation in TAVI clinical research programs. Important considerations in developing endpoint definitions included (i) respect for the historical legacy of surgical valve guidelines; (ii) identification of pathophysiological mechanisms associated with clinical events; (iii) emphasis on clinical relevance. Consensus criteria were developed for the following endpoints: mortality, myocardial infarction, stroke, bleeding, acute kidney injury, vascular complications, and prosthetic valve performance. Composite

  11. Embryonic and fetal mortality in river buffalo (Bubalus bubalis).

    PubMed

    Campanile, Giuseppe; Neglia, Gianluca; D'Occhio, Michael J

    2016-07-01

    River buffalo are able to adapt to diverse climatic zones and are widespread globally. The resource use efficiency of buffalo is highly relevant in a resource-constrained world and the increasing requirement to produce more food. Buffalo clearly have an important role in meeting the growing demand for animal protein. In the Mediterranean and higher latitudes, buffalo show annual cycles of ovarian activity, embryonic development, and pregnancy rate. In buffalo, the CL starts to develop early in the cycle, and there is also an early increase in concentrations of progesterone (P4) in circulation. This appears to be necessary for optimal embryonic development. The failure to establish a pregnancy in buffalo can occur before Day 21 (early embryonic mortality), from Day 21 to 45 (late embryonic mortality), and from Day 46 to 90 (fetal mortality) after mating. Treatment with P4, hCG, and GnRH on Day 5 after mating increases P4 in circulation and reduces early embryonic mortality in circumstances where concentrations of P4 are relatively low. The same treatments applied on Day 20 to 25 after mating can lower the occurrence of late embryonic mortality and fetal mortality. PMID:27142486

  12. Critical Transitions in Early Embryonic Aortic Arch Patterning and Hemodynamics

    PubMed Central

    Kowalski, William J.; Dur, Onur; Wang, Yajuan; Patrick, Michael J.; Tinney, Joseph P.; Keller, Bradley B.; Pekkan, Kerem

    2013-01-01

    Transformation from the bilaterally symmetric embryonic aortic arches to the mature great vessels is a complex morphogenetic process, requiring both vasculogenic and angiogenic mechanisms. Early aortic arch development occurs simultaneously with rapid changes in pulsatile blood flow, ventricular function, and downstream impedance in both invertebrate and vertebrate species. These dynamic biomechanical environmental landscapes provide critical epigenetic cues for vascular growth and remodeling. In our previous work, we examined hemodynamic loading and aortic arch growth in the chick embryo at Hamburger-Hamilton stages 18 and 24. We provided the first quantitative correlation between wall shear stress (WSS) and aortic arch diameter in the developing embryo, and observed that these two stages contained different aortic arch patterns with no inter-embryo variation. In the present study, we investigate these biomechanical events in the intermediate stage 21 to determine insights into this critical transition. We performed fluorescent dye microinjections to identify aortic arch patterns and measured diameters using both injection recordings and high-resolution optical coherence tomography. Flow and WSS were quantified with 3D computational fluid dynamics (CFD). Dye injections revealed that the transition in aortic arch pattern is not a uniform process and multiple configurations were documented at stage 21. CFD analysis showed that WSS is substantially elevated compared to both the previous (stage 18) and subsequent (stage 24) developmental time-points. These results demonstrate that acute increases in WSS are followed by a period of vascular remodeling to restore normative hemodynamic loading. Fluctuations in blood flow are one possible mechanism that impacts the timing of events such as aortic arch regression and generation, leading to the variable configurations at stage 21. Aortic arch variations noted during normal rapid vascular remodeling at stage 21 identify a

  13. Motor adaptation to Coriolis force perturbations of reaching movements: endpoint but not trajectory adaptation transfers to the nonexposed arm

    NASA Technical Reports Server (NTRS)

    Dizio, P.; Lackner, J. R.

    1995-01-01

    1. Reaching movements made in a rotating room generate Coriolis forces that are directly proportional to the cross product of the room's angular velocity and the arm's linear velocity. Such Coriolis forces are inertial forces not involving mechanical contact with the arm. 2. We measured the trajectories of arm movements made in darkness to a visual target that was extinguished at the onset of each reach. Prerotation subjects pointed with both the right and left arms in alternating sets of eight movements. During rotation at 10 rpm, the subjects reached only with the right arm. Postrotation, the subjects pointed with the left and right arms, starting with the left, in alternating sets of eight movements. 3. The initial perrotary reaching movements of the right arm were highly deviated both in movement path and endpoint relative to the prerotation reaches of the right arm. With additional movements, subjects rapidly regained straight movement paths and accurate endpoints despite the absence of visual or tactile feedback about reaching accuracy. The initial postrotation reaches of the left arm followed straight paths to the wrong endpoint. The initial postrotation reaches of the right arm had paths with mirror image curvature to the initial perrotation reaches of the right arm but went to the correct endpoint. 4. These observations are inconsistent with current equilibrium point models of movement control. Such theories predict accurate reaches under our experimental conditions. Our observations further show independent implementation of movement and posture, as evidenced by transfer of endpoint adaptation to the nonexposed arm without transfer of path adaptation. Endpoint control may occur at a relatively central stage that represents general constraints such as gravitoinertial force background or egocentric direction relative to both arms, and control of path may occur at a more peripheral stage that represents moments of inertia and muscle dynamics unique to each

  14. Optical emission spectroscopy analysis for Ge2Sb2Te5 etching endpoint detection in HBr/He plasma

    NASA Astrophysics Data System (ADS)

    Li, Juntao; Liu, Bo; Song, Zhitang; Feng, Gaoming; Wu, Guanping; He, Aodong; Yang, Zuoya; Zhu, Nanfei; Xu, Jia; Ren, Jiadong; Feng, Songlin

    In the fabrication of phase change memory devices, HBr/He gas is employed in patterning Ge2Sb2Te5 (GST) because it is damage free to GST sidewall. Accurate and reproducible endpoint detection methods are necessary in this etching process. In-situ optical emission spectroscopy (OES) is collected and analyzed to control the GST etching process due to its non-invasiveness. By analyzing the light emitted from plasma, we report an effective etch endpoint detection method for GST etching process is developed and the results are also confirmed using scanning electron micrographs.

  15. Endpoint-based parallel data processing with non-blocking collective instructions in a parallel active messaging interface of a parallel computer

    DOEpatents

    Archer, Charles J; Blocksome, Michael A; Cernohous, Bob R; Ratterman, Joseph D; Smith, Brian E

    2014-11-11

    Endpoint-based parallel data processing with non-blocking collective instructions in a PAMI of a parallel computer is disclosed. The PAMI is composed of data communications endpoints, each including a specification of data communications parameters for a thread of execution on a compute node, including specifications of a client, a context, and a task. The compute nodes are coupled for data communications through the PAMI. The parallel application establishes a data communications geometry specifying a set of endpoints that are used in collective operations of the PAMI by associating with the geometry a list of collective algorithms valid for use with the endpoints of the geometry; registering in each endpoint in the geometry a dispatch callback function for a collective operation; and executing without blocking, through a single one of the endpoints in the geometry, an instruction for the collective operation.

  16. Genetic Exploration of the Exit from Self-Renewal Using Haploid Embryonic Stem Cells

    PubMed Central

    Leeb, Martin; Dietmann, Sabine; Paramor, Maike; Niwa, Hitoshi; Smith, Austin

    2014-01-01

    Summary Self-renewal circuitry in embryonic stem cells (ESCs) is increasingly defined. How the robust pluripotency program is dissolved to enable fate transition is less appreciated. Here we develop a forward genetic approach using haploid ESCs. We created libraries of transposon integrations and screened for persistent self-renewal in differentiation-permissive culture. This yielded multiple mutants in the Fgf/Erk and GSK3/Tcf3 modules known to drive differentiation and in epigenetic modifiers implicated in lineage commitment. We also identified and validated factors not previously considered. These include the conserved small zinc finger protein Zfp706 and the RNA binding protein Pum1. Pum1 targets several mRNAs for naive pluripotency transcription factors and accelerates their downregulation at the onset of differentiation. These findings indicate that the dismantling of pluripotent circuitry proceeds at multiple levels. More broadly they exemplify the power of haploid ESCs for genetic interrogation of developmental processes. PMID:24412312

  17. Hermes III endpoint energy calculation from photonuclear activation of 197Au and 58Ni foils

    SciTech Connect

    Parzyck, Christopher Thomas

    2014-09-01

    A new process has been developed to characterize the endpoint energy of HERMES III on a shot-to-shot basis using standard dosimetry tools from the Sandia Radiation Measurements Laboratory. Photonuclear activation readings from nickel and gold foils are used in conjunction with calcium fluoride thermoluminescent dosimeters to derive estimated electron endpoint energies for a series of HERMES shots. The results are reasonably consistent with the expected endpoint voltages on those shots.

  18. Immunostaining of dissected zebrafish embryonic heart.

    PubMed

    Yang, Jingchun; Xu, Xiaolei

    2012-01-01

    Zebrafish embryo becomes a popular in vivo vertebrate model for studying cardiac development and human heart diseases due to its advantageous embryology and genetics. About 100-200 embryos are readily available every week from a single pair of adult fish. The transparent embryos that develop ex utero make them ideal for assessing cardiac defects. The expression of any gene can be manipulated via morpholino technology or RNA injection. Moreover, forward genetic screens have already generated a list of mutants that affect different perspectives of cardiogenesis. Whole mount immunostaining is an important technique in this animal model to reveal the expression pattern of the targeted protein to a particular tissue. However, high resolution images that can reveal cellular or subcellular structures have been difficult, mainly due to the physical location of the heart and the poor penetration of the antibodies. Here, we present a method to address these bottlenecks by dissecting heart first and then conducting the staining process on the surface of a microscope slide. To prevent the loss of small heart samples and to facilitate solution handling, we restricted the heart samples within a circle on the surface of the microscope slides drawn by an immEdge pen. After the staining, the fluorescence signals can be directly observed by a compound microscope. Our new method significantly improves the penetration for antibodies, since a heart from an embryonic fish only consists of few cell layers. High quality images from intact hearts can be obtained within a much reduced procession time for zebrafish embryos aged from day 2 to day 6. Our method can be potentially extended to stain other organs dissected from either zebrafish or other small animals. PMID:22258109

  19. Neurovascular anatomy of the embryonic quail hindlimb.

    PubMed

    Bentley, Matthew T; Poole, Thomas J

    2009-10-01

    Blood vessel and nerve development in the vertebrate embryo possess certain similarities in pattern and molecular guidance cues. To study the specific influence of shared guidance molecules on nervous and vascular development, an understanding of the normal neurovascular anatomy must be in place. The present study documents the pattern of nervous and vascular development in the Japanese quail hindlimb using immunohistochemistry and fluorescently labeled intravital injection combined with confocal and epifluorescent microscopy. The developmental patterns of major nerves and blood vessels of embryonic hindlimbs between stages E2.75 (HH18) and E6.0 (HH29) are described. By E2.75, the dorsal aortae have begun to fuse into a single vessel at the level of the hindlimb, and have completely fused by E3 (HH20). The posterior cardinal vein is formed at the level of the hindlimb by E3, as is the main artery of the early hindlimb, the ischiadic artery, as an offshoot of the dorsal aorta. Our data suggest that eight spinal segments, versus seven as reported by others (Tanaka and Landmesser,1986a; Tyrrell et al.,1990), contribute to innervation of the quail hindlimb. Lumbosacral neurites reach the plexus region by E3.5 (HH21 & 22), pause for approximately 24 hr, and then enter the hindlimb along with the ischiadic and crural arteries through shared foramina in the pelvic anlage. The degree of anterior-posterior spatial congruency between major nerves and blood vessels of the quail hindlimb was found to be highest medial to the pelvic girdle precursor, versus in the hindlimb proper. PMID:19685501

  20. Purinergic receptors in embryonic and adult neurogenesis.

    PubMed

    Oliveira, Ágatha; Illes, Peter; Ulrich, Henning

    2016-05-01

    ATP (adenosine 5'-triphosphate), one of the most ancient neurotransmitters, exerts essential functions in the brain, including neurotransmission and modulation of synaptic activity. Moreover, this nucleotide has been attributed with trophic properties and experimental evidence points to the participation of ATP-activated P2X and P2Y purinergic receptors in embryonic brain development as well as in adult neurogenesis for maintenance of normal brain functions and neuroregeneration upon brain injury. We discuss here the available data on purinergic P2 receptor expression and function during brain development and in the neurogenic zones of the adult brain, as well as the insights based on the use of in vitro stem cell cultures. While several P2 receptor subtypes were shown to be expressed during in vitro and in vivo neurogenesis, specific functions have been proposed for P2Y1, P2Y2 metabotropic as well as P2X2 ionotropic receptors to promote neurogenesis. Further, the P2X7 receptor is suggested to function in the maintenance of pools of neural stem and progenitor cells through induction of proliferation or cell death, depending on the microenvironment. Pathophysiological actions have been proposed for this receptor in worsening damage in brain disease. The P2X7 receptor and possibly additional P2 receptor subtypes have been implicated in pathophysiology of neurological diseases including Parkinson's disease, Alzheimer's disease and epilepsy. New strategies in cell therapy could involve modulation of purinergic signaling, either in the achievement of more effective protocols to obtain viable and homogeneous cell populations or in the process of functional engraftment of transplanted cells into the damaged brain. This article is part of the Special Issue entitled 'Purines in Neurodegeneration and Neuroregeneration'. PMID:26456352

  1. Nucleosome Organization in Human Embryonic Stem Cells

    PubMed Central

    Taylor, Jared F.; Khattab, Omar S.; Chen, Yu-Han; Chen, Yumay; Jacobsen, Steven E.; Wang, Ping H.

    2015-01-01

    The fundamental repeating unit of eukaryotic chromatin is the nucleosome. Besides being involved in packaging DNA, nucleosome organization plays an important role in transcriptional regulation and cellular identity. Currently, there is much debate about the major determinants of the nucleosome architecture of a genome and its significance with little being known about its role in stem cells. To address these questions, we performed ultra-deep sequencing of nucleosomal DNA in two human embryonic stem cell lines and integrated our data with numerous epigenomic maps. Our analyses have revealed that the genome is a determinant of nucleosome organization with transcriptionally inactive regions characterized by a “ground state” of nucleosome profiles driven by underlying DNA sequences. DNA sequence preferences are associated with heterogeneous chromatin organization around transcription start sites. Transcription, histone modifications, and DNA methylation alter this “ground state” by having distinct effects on both nucleosome positioning and occupancy. As the transcriptional rate increases, nucleosomes become better positioned. Exons transcribed and included in the final spliced mRNA have distinct nucleosome profiles in comparison to exons not included at exon-exon junctions. Genes marked by the active modification H3K4m3 are characterized by lower nucleosome occupancy before the transcription start site compared to genes marked by the inactive modification H3K27m3, while bivalent domains, genes associated with both marks, lie exactly in the middle. Combinatorial patterns of epigenetic marks (chromatin states) are associated with unique nucleosome profiles. Nucleosome organization varies around transcription factor binding in enhancers versus promoters. DNA methylation is associated with increasing nucleosome occupancy and different types of methylations have distinct location preferences within the nucleosome core particle. Finally, computational analysis of

  2. Nutrient reference value: non-communicable disease endpoints--a conference report.

    PubMed

    Lupton, J R; Blumberg, J B; L'Abbe, M; LeDoux, M; Rice, H B; von Schacky, C; Yaktine, A; Griffiths, J C

    2016-03-01

    scientific evidence does exist to confirm a relationship between the intake of a specific bioactive constituent and enhanced health conditions or reduced risk of a chronic disease. Further, research on the putative mechanisms of action of various classes of bioactives is supported by national and pan-national government agencies, and academic institutions, as well as functional food and dietary supplement manufacturers. Consumers are becoming educated and are seeking to purchase products containing bioactives, yet there is no evaluative process in place to let the public know how strong the science is behind the benefits or the quantitative amounts needed to achieve these beneficial health effects or to avoid exceeding the upper level (UL). When one lacks an essential nutrient, overt deficiency with concomitant physiological determents and eventually death are expected. The absence of bioactive substances from the diet results in suboptimal health, e.g., poor cellular and/or physiological function, which is relative and not absolute. Regrettably at this time, there is no DRI process to evaluate bioactives, although a recent workshop convened by the National Institutes of Health (Options for Consideration of Chronic Disease Endpoints for Dietary Reference Intakes (DRIs); March 10-11, 2015; http://health.gov/dietaryguidelines/dri/ ) did explore the process to develop DVs for nutrients, the lack of which result in increased risk of chronic disease (non-communicable disease) endpoints. A final report is expected soon. This conference (CRN-International Scientific Symposium; "Nutrient Reference Value-Non-Communicable Disease (NRV-NCD) Endpoints," 20 November in Kronberg, Germany; http://www.crn-i.ch/2015symposium/ ) explores concepts related to the Codex NRV process, the public health opportunities in setting NRVs for bioactive constituents, and further research and details on the specific class of bioactives, n-3 long-chain polyunsaturated fatty acids (also termed omega-3 fatty

  3. Expression of biomarker genes of differentiation in D3 mouse embryonic stem cells after exposure to different embryotoxicant and non-embryotoxicant model chemicals

    PubMed Central

    Romero, Andrea C.; del Río, Eva; Vilanova, Eugenio; Sogorb, Miguel A.

    2015-01-01

    There is a necessity to develop in vitro methods for testing embryotoxicity (Romero et al., 2015) [1]. We studied the progress of D3 mouse embryonic stem cells differentiation exposed to model embryotoxicants and non-embryotoxicants chemicals through the expression of biomarker genes. We studied a set of 16 different genes biomarkers of general cellular processes (Cdk1, Myc, Jun, Mixl, Cer and Wnt3), ectoderm formation (Nrcam, Nes, Shh and Pnpla6), mesoderm formation (Mesp1, Vegfa, Myo1e and Hdac7) and endoderm formation (Flk1 and Afp). We offer dose response in order to derive the concentration causing either 50% or 200% of expression of the biomarker gene. These records revealed to be a valuable end-point to predict in vitro the embryotoxicity of chemicals (Romero et al., 2015) [1]. PMID:26568980

  4. Timing of prenatal phthalate exposure in relation to genital endpoints in male newborns.

    PubMed

    Martino-Andrade, A J; Liu, F; Sathyanarayana, S; Barrett, E S; Redmon, J B; Nguyen, R H N; Levine, H; Swan, S H

    2016-07-01

    Prior studies report that penile size and male anogenital distance (AGD), sensitive markers of androgen action in utero, may be shortened by prenatal exposure to certain phthalates, including diethylhexyl phthalate (DEHP), but no human study has investigated the importance of exposure timing in these associations. The aim of this study was to examine the significance of exposure timing on the action of prenatal phthalates in particular DEHP, on male infant penile size and AGD. In The Infant Development and the Environment Study (TIDES) we measured penile width (PW) as well as anoscrotal distance (AGDAS ) and anopenile distance (AGPAP ) in newborn males. We modeled these endpoints in relation to phthalate metabolite concentrations in maternal urine samples collected in each trimester (T1, T2, and T3) in a subset of TIDES mothers (N = 168). PW was inversely associated with T2 oxidized DEHP metabolites, mono-2-ethyl-5-oxohexyl (MEOHP, β=-0.48; 95% confidence interval, -0.93, -0.02), MEHHP (-0.48; -0.92, -0.05), mono-2-ethyl-5-carboxypentyl (MECPP, -0.51; -1.01, -0.004), although no appreciable associations were seen between PW and T1 and T3 DEHP metabolite concentrations in this subset. Concentrations of DEHP metabolites in T1 urine samples were inversely related to male AGD. For example, in T1 samples in this subset of women mono-2-ethyl-5-hydroxyhexyl (MEHHP) was inversely associated with male AGDAP (β = -1.73; 95% confidence interval, -3.45, 0.0004). However, no appreciable associations were seen between AGD measures and any DEHP metabolite in T2 and T3 samples. These data suggest that DEHP exposure is inversely associated with AGD and PW, with PW primarily associated with T2 exposure and AGD associations seen only for T1 exposure, but no associations were found between T3 DEHP metabolites and any of these genital endpoints. These findings are consistent with data on critical windows in rodent studies, supporting the biological plausibility of these

  5. Acute effects of a prooxidant herbicide on the microalga Chlamydomonas reinhardtii: Screening cytotoxicity and genotoxicity endpoints.

    PubMed

    Esperanza, Marta; Cid, Ángeles; Herrero, Concepción; Rioboo, Carmen

    2015-08-01

    Since recent evidence has demonstrated that many types of chemicals exhibit oxidative and/or genotoxic potential on living organisms, reactive oxygen species (ROS) formation and DNA damage are currently the best accepted paradigms to assess the potential hazardous biological effects of a wide range of contaminants. The goal of this study was to evaluate the sensitivity of different cytotoxicity and genotoxicity responses on the model microalga Chlamydomonas reinhardtii exposed to the prooxidant herbicide paraquat. In addition to the growth endpoint, cell viability, mitochondrial membrane potential and presence of reactive oxygen species (ROS) were assayed as potential markers of cytotoxicity using flow cytometry (FCM). To study the effects of paraquat on C. reinhardtii DNA, several genotoxicity approaches were implemented for the first time in an ecotoxicological study on microalgae. Oxidative DNA base damage was analysed by measuring the oxidative DNA lesion 8-OHdG by FCM. DNA fragmentation was analysed by different methods: comet assay, and cell cycle analysis by FCM, with a particular focus on the presence of subG1-nuclei. Finally, effects on morphology of nuclei were monitored through DAPI staining. The evaluation of these endpoints showed that several physiological and biochemical parameters reacted to oxidative stress disturbances with greater sensitivity than integrative parameters such as growth rates or cell viability. The experiments revealed concentration-dependent cytotoxicity (ROS formation, depolarization of mitochondrial membrane), genotoxicity (oxidative DNA damage, DNA strand breakage, alterations in nuclear morphology), and cell cycle disturbances (subG1-nuclei, decrease of 4N population) in paraquat-treated cells. Overall, the genotoxicity results indicate that the production of ROS caused by exposure to paraquat induces oxidative DNA damage followed by DNA single- and double-strand breaks and cell cycle alterations, possibly leading to apoptosis

  6. Multiple Sclerosis

    MedlinePlus

    Multiple sclerosis (MS) is a nervous system disease that affects your brain and spinal cord. It damages the ... attacks healthy cells in your body by mistake. Multiple sclerosis affects women more than men. It often begins ...

  7. Multiple Pregnancy

    MedlinePlus

    ... is called multiple pregnancy . If more than one egg is released during the menstrual cycle and each ... fraternal twins (or more). When a single fertilized egg splits, it results in multiple identical embryos. This ...

  8. Multiple myeloma

    MedlinePlus

    Plasma cell dyscrasia; Plasma cell myeloma; Malignant plasmacytoma; Plasmacytoma of bone; Myeloma - multiple ... Multiple myeloma most commonly causes: Low red blood cell count ( anemia ), which can lead to fatigue and ...

  9. 76 FR 35450 - Draft Guidance for Industry on Clinical Trial Endpoints for the Approval of Non-Small Cell Lung...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    .... This guidance does not address endpoints for drugs to prevent or decrease the incidence of lung cancer... the Approval of Non-Small Cell Lung Cancer Drugs and Biologics; Availability AGENCY: Food and Drug... Cell Lung Cancer Drugs and Biologics.'' This draft guidance provides recommendations to applicants...

  10. A vision-based end-point control for a two-link flexible manipulator. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Obergfell, Klaus

    1991-01-01

    The measurement and control of the end-effector position of a large two-link flexible manipulator are investigated. The system implementation is described and an initial algorithm for static end-point positioning is discussed. Most existing robots are controlled through independent joint controllers, while the end-effector position is estimated from the joint positions using a kinematic relation. End-point position feedback can be used to compensate for uncertainty and structural deflections. Such feedback is especially important for flexible robots. Computer vision is utilized to obtain end-point position measurements. A look-and-move control structure alleviates the disadvantages of the slow and variable computer vision sampling frequency. This control structure consists of an inner joint-based loop and an outer vision-based loop. A static positioning algorithm was implemented and experimentally verified. This algorithm utilizes the manipulator Jacobian to transform a tip position error to a joint error. The joint error is then used to give a new reference input to the joint controller. The convergence of the algorithm is demonstrated experimentally under payload variation. A Landmark Tracking System (Dickerson, et al 1990) is used for vision-based end-point measurements. This system was modified and tested. A real-time control system was implemented on a PC and interfaced with the vision system and the robot.

  11. Nature of Roberge-Weiss transition endpoints for heavy quarks in Nf=2 lattice QCD with Wilson fermions

    NASA Astrophysics Data System (ADS)

    Wu, Liang-Kai; Meng, Xiang-Fei

    2014-11-01

    The phase structure of QCD with imaginary chemical potential provides information on the phase diagram of QCD with real chemical potential. With imaginary chemical potential i μI=i π T , previous studies show that the Roberge-Weiss (RW) transition endpoints are triple points at both large and small quark masses, and second order transition points at intermediate quark masses. The triple and second order endpoints are separated by two tricritical ones. We present simulations with Nf=2 Wilson fermions to investigate the nature of RW transition endpoints. The simulations are carried out at 8 values of the hopping parameter κ ranging from 0.020 to 0.140 on different lattice volumes. The Binder cumulant, susceptibility, and reweighted distribution of the imaginary part of the Polyakov loop are employed to determine the nature of RW transition endpoints. The simulations show that the two tricritical points are within the ranges 0.070-0.080 and 0.120-0.140, respectively.

  12. DEVELOPMENT OF QUANTITATIVE STRUCTURE ACTIVITY RELATIONSHIPS (QSARS) TO PREDICT TOXICITY FOR A VARIETY OF HUMAN AND ECOLOGICAL ENDPOINTS

    EPA Science Inventory

    A web accessible software tool is being developed to predict the toxicity of unknown chemicals for a wide variety of endpoints. The tool will enable a user to easily predict the toxicity of a query compound by simply entering its structure in a 2-dimensional (2-D) chemical sketc...

  13. Energetic endpoints provide early indicators of life history effects in a freshwater gastropod exposed to the fungicide, pyraclostrobin.

    PubMed

    Fidder, Bridgette N; Reátegui-Zirena, Evelyn G; Olson, Adric D; Salice, Christopher J

    2016-04-01

    Organismal energetics provide important insights into the effects of environmental toxicants. We aimed to determine the effects of pyraclostrobin on Lymnaea stagnalis by examining energy allocation patterns and life history traits. Juvenile snails exposed to pyraclostrobin decreased feeding rate and increased apparent avoidance behaviors at environmentally relevant concentrations. In adults, we found that sublethal concentrations of pyraclostrobin did not affect reproductive output, however, there were significant effects on developmental endpoints with longer time to hatch and decreased hatching success in pyraclostrobin-exposed egg masses. Further, there were apparent differences in developmental effects depending on whether mothers were also exposed to pyraclostrobin suggesting this chemical can exert intergenerational effects. Pyraclostrobin also affected protein and carbohydrate content of eggs in mothers that were exposed to pyraclostrobin. Significant effects on macronutrient content of eggs occurred at lower concentrations than effects on gross endpoints such as hatching success and time to hatch suggesting potential value for these endpoints as early indicators of ecologically relevant stress. These results provide important insight into the effects of a common fungicide on important endpoints for organismal energetics and life history. PMID:26766536

  14. On the relationship between the causal-inference and meta-analytic paradigms for the validation of surrogate endpoints.

    PubMed

    Alonso, Ariel; Van der Elst, Wim; Molenberghs, Geert; Buyse, Marc; Burzykowski, Tomasz

    2015-03-01

    The increasing cost of drug development has raised the demand for surrogate endpoints when evaluating new drugs in clinical trials. However, over the years, it has become clear that surrogate endpoints need to be statistically evaluated and deemed valid, before they can be used as substitutes of "true" endpoints in clinical studies. Nowadays, two paradigms, based on causal-inference and meta-analysis, dominate the scene. Nonetheless, although the literature emanating from these paradigms is wide, till now the relationship between them has largely been left unexplored. In the present work, we discuss the conceptual framework underlying both approaches and study the relationship between them using theoretical elements and the analysis of a real case study. Furthermore, we show that the meta-analytic approach can be embedded within a causal-inference framework on the one hand and that it can be heuristically justified why surrogate endpoints successfully evaluated using this approach will often be appealing from a causal-inference perspective as well, on the other. A newly developed and user friendly R package Surrogate is provided to carry out the evaluation exercise. PMID:25274284

  15. Finger Multiplication

    ERIC Educational Resources Information Center

    Simanihuruk, Mudin

    2011-01-01

    Multiplication facts are difficult to teach. Therefore many researchers have put a great deal of effort into finding multiplication strategies. Sherin and Fuson (2005) provided a good survey paper on the multiplication strategies research area. Kolpas (2002), Rendtorff (1908), Dabell (2001), Musser (1966) and Markarian (2009) proposed the finger…

  16. Multiple Sclerosis

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS NINDS Multiple Sclerosis Information Page Condensed from Multiple Sclerosis: Hope Through ... en Español Additional resources from MedlinePlus What is Multiple Sclerosis? An unpredictable disease of the central nervous system, ...

  17. Expression of CGRP in embryonic mouse masseter muscle.

    PubMed

    Azuma, Yuri; Miwa, Yoko; Sato, Iwao

    2016-07-01

    Neuropeptide calcitonin gene-related peptide (CGRP) is a mediator of inflammation and head pain that influences the functional vascular blood supply. The CGRP also regulate myoblast and acetylcholine receptors on neuromuscular junctions in development. However, little is known about its appearance and location during mouse masseter muscle (MM) development. We detected the mRNA abundance of CGRP, vascular genesis markers (Vascular endothelial growth factor A (VEGF-A), PECAM (CD31), lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1)) and embryonic and adult myosin heavy chain (MyHCs) (embryonic, IIa, IIb, and IIx) using real-time RT-PCR during development from the embryonic stage to after birth (E12.5, E14.5, E17.5, E18.5, P0, P1 and P5). We also endeavored to analyze the expression and localization of CGRP in situ hybridization in the developing mouse MM during development from the embryonic stage to after birth (E12.5, E14.5, E17.5, and P1). The antisense probe for CGRP was detected by in situ hybridization at E12.5, E14.5 E17.5 and then no longer detected after birth. The CGRP, CD31, embryonic MyHC abundance levels are highest at E17.5 (p<0.001) and they show a pattern similar to that of the other markers from E12.5 to P5. PCA analysis indicates a specific relation between CGRP and embryonic MyHC, CD31, and LYVE-1 in MM development. Cluster analyses identified the following distinct clusters for mRNA abundance in the MM: cluster 1, P5; cluster 2, E12.5, E14.5, E17.5, E18.5, P0, and P1. The positive correlation between CGRP and embryonic MyHC (Pearson's r>0.65; p<0.01) was analyzed. These data suggested that CGRP may have an influence on embryonic MyHC during mouse MM development. CGRP also affects the angiogenesis markers at embryonic stages. PMID:27136747

  18. Update of the International Consensus on Palliative Radiotherapy Endpoints for Future Clinical Trials in Bone Metastases

    SciTech Connect

    Chow, Edward; Hoskin, Peter; Mitera, Gunita; Zeng Liang; Lutz, Stephen; Roos, Daniel; Hahn, Carol; Linden, Yvette van der; Hartsell, William; Kumar, Eshwar

    2012-04-01

    Purpose: To update the international consensus on palliative radiotherapy endpoints for future clinical trials in bone metastases by surveying international experts regarding previous uncertainties within the 2002 consensus, changes that may be necessary based on practice pattern changes and research findings since that time. Methods and Materials: A two-phase survey was used to determine revisions and new additions to the 2002 consensus. A total of 49 experts from the American Society for Radiation Oncology, the European Society for Therapeutic Radiology and Oncology, the Faculty of Radiation Oncology of the Royal Australian and New Zealand College of Radiologists, and the Canadian Association of Radiation Oncology who are directly involved in the care of patients with bone metastases participated in this survey. Results: Consensus was established in areas involving response definitions, eligibility criteria for future trials, reirradiation, changes in systemic therapy, radiation techniques, parameters at follow-up, and timing of assessments. Conclusion: An outline for trials in bone metastases was updated based on survey and consensus. Investigators leading trials in bone metastases are encouraged to adopt the revised guideline to promote consistent reporting. Areas for future research were identified. It is intended for the consensus to be re-examined in the future on a regular basis.

  19. Determining significant endpoints for ecological risk analyses. 1997 annual progress report

    SciTech Connect

    Hinton, T.G.; Congdon, J.; Rowe, C.; Scott, D.; Bedford, J.; Whicker, F.W.

    1997-11-01

    'This report summarizes the first year''s progress of research funded under the Department of Energy''s Environmental Management Science Program. The research was initiated to better determine ecological risks from toxic and radioactive contaminants. More precisely, the research is designed to determine the relevancy of sublethal cellular damage to the performance of individuals and to identify characteristics of non-human populations exposed to chronic, low-level radiation, as is typically found on many DOE sites. The authors propose to establish a protocol to assess risks to non-human species at higher levels of biological organization by relating molecular damage to more relevant responses that reflect population health. They think that they can achieve this by coupling changes in metabolic rates and energy allocation patterns to meaningful population response variables, and by using novel biological dosimeters in controlled, manipulative dose/effects experiments. They believe that a scientifically defensible endpoint for measuring ecological risks can only be determined once its understood the extent to which molecular damage from contaminant exposure is detrimental at the individual and population levels of biological organization.'

  20. Biological and chemical tests of contaminated soils to determine bioavailability and environmentally acceptable endpoints (EAE)

    SciTech Connect

    Montgomery, C.R.; Menzie, C.A.; Pauwells, S.J.

    1995-12-31

    The understanding of the concept of bioavailability of soil contaminants to receptors and its use in supporting the development of EAE is growing but still incomplete. Nonetheless, there is increased awareness of the importance of such data to determine acceptable cleanup levels and achieve timely site closures. This presentation discusses a framework for biological and chemical testing of contaminated soils developed as part of a Gas Research Institute (GRI) project entitled ``Environmentally Acceptable Endpoints in Soil Using a Risk Based Approach to Contaminated Site Management Based on Bioavailability of Chemicals in Soil.`` The presentation reviews the GRI program, and summarizes the findings of the biological and chemical testing section published in the GRI report. The three primary components of the presentation are: (1) defining the concept of bioavailability within the existing risk assessment paradigm, (2) assessing the usefulness of the existing tests to measure bioavailability and test frameworks used to interpret these measurements, and (3) suggesting how a small selection of relevant tests could be incorporated into a flexible testing scheme for soils to address this issue.

  1. Rethinking end-points for bone-targeted therapy in advanced cancer.

    PubMed

    Gómez García, Susana; Clemons, Mark; Amir, Eitan

    2016-08-01

    The principal objective for any medical therapy is to improve either the duration of life and/or its quality. Metastases in bone can lead to clinically defined events termed skeletal-related events (SREs) which are a quantifiable measure of skeletal morbidity. Avoidance and/or delay of SREs have become the principal objective in trials exploring the efficacy of bone-targeted therapy in patients with skeletal metastases. Despite reductions in the frequency or rate of SRE occurrence, trials of bone-targeted therapy have failed to show any effect on either progression-free or overall survival when compared with placebo or other bone-targeting agents. Similarly, trials of bone-targeted therapy have not shown consistent effects on quality of life. The validity of SRE-based primary outcome measures in cancer clinical trials is therefore, questionable. More novel end-point selection for trials of bone-targeted therapy seems warranted. Composite measures comprising occurrence of symptomatic skeletal events and patient reported outcomes may be an effective solution and warrants further investigation. PMID:27299662

  2. Injury to the lung from cancer therapy: Clinical syndromes, measurable endpoints, and potential scoring systems

    SciTech Connect

    McDonald, S.; Rubin, P.; Phillips, T.L.

    1995-03-30

    Toxicity of the respiratory system is a common side effect and complication of anticancer therapy that can result in significant morbidity. The range of respiratory compromise can extend from acute lethal events to degrees of chronic pulmonary decompensation, manifesting years after the initial cancer therapy. This review examines the anatomic-histologic background of the lung and the normal functional anatomic unit. The pathophysiology of radiation and chemotherapy induced lung injury is discussed as well as the associated clinical syndromes. Radiation tolerance doses and volumes are assessed in addition to chemotherapy tolerance and risk factors and radiation-chemotherapy interactions. There are a variety of measurable endpoints for detection and screening. Because of the wide range of available quantitative tests, it would seem that the measurement of impaired lung function is possible. The development of staging systems for acute and late toxicity is discussed an a new staging system for Late Effects in Normal Tissues :(LENT) is proposed. 115 refs., 2 figs., 9 tabs.

  3. Augmented case-only designs for randomized clinical trials with failure time endpoints

    PubMed Central

    2015-01-01

    Summary Under suitable assumptions and by exploiting the independence between inherited genetic susceptibility and treatment assignment, the case-only design yields efficient estimates for subgroup treatment effects and gene-treatment interaction in a Cox model. However it cannot provide estimates of the genetic main effect and baseline hazards, that are necessary to compute the absolute disease risk. For two-arm, placebo-controlled trials with rare failure time endpoints, we consider augmenting the case-only design with random samples of controls from both arms, as in the classical case-cohort sampling scheme, or with a random sample of controls from the active treatment arm only. The latter design is motivated by vaccine trials for cost-effective use of resources and specimens so that host genetics and vaccine-induced immune responses can be studied simultaneously in a bigger set of participants. We show that these designs can identify all parameters in a Cox model and that the efficient case-only estimator can be incorporated in a two-step plug-in procedure. Results in simulations and a data example suggest that incorporating case-only estimators in the classical case-cohort design improves the precision of all estimated parameters; sampling controls only in the active treatment arm attains a similar level of efficiency. PMID:26347982

  4. Sample preparation and characterization for a study of environmentally acceptable endpoints for hydrocarbon-contaminated soil

    SciTech Connect

    Kreitinger, J.P.; Finn, J.T.

    1995-12-31

    In the past, the interdisciplinary research effort required to investigate the acceptable cleanup endpoints for hydrocarbon-impacted soils has been limited by the lack of standardized soils for testing. To support the efforts of the various researchers participating in the EAE research initiative, soil samples were collected from ten sites representing hydrocarbon-impacted soils typical of exploration/production, refinery, and bulk storage terminal operations. The hydrocarbons in the standard soils include crude oil, mixed refinery products, diesel, gasoline, and jet fuel. Physical characterization included analysis of soil texture, water retention, particle density, nanoporosity, pH, electrical conductivity, cation exchange capacity, buffer capacity, organic carbon, sodium adsorption ratio, and clay mineralogy. Chemical characterization included analysis of total recoverable petroleum hydrocarbons, total volatile and semivolatile organic compounds and metals, and TCLP for metals and organics. An analysis of the aliphatic and aromatic hydrocarbon fractions was performed on each soil to support the use of various models for assessing soil toxicity. Screening-level toxicity tests were conducted using Microtox{trademark}, plant seed germination and growth, and earthworm mortality and growth. Biodegradability screening tests were performed in slurry shake flasks to estimate the availability of hydrocarbon fractions to soil microorganisms.

  5. Analysis of In-Situ Vibration Monitoring for End-Point Detection of CMP Planarization Processes

    SciTech Connect

    Hetherington, Dale L.; Lauffer, James P.; Shingledecker, David M.; Stein, David J.; Wyckoff, Edward E.

    1999-05-14

    This paper details the analysis of vibration monitoring for end-point control in oxide CMP processes. Two piezoelectric accelerometers were integrated onto the backside of a stainless steel polishing head of an IPEC 472 polisher. One sensor was placed perpendicular to the carrier plate (vertical) and the other parallel to the plate (horizontal). Wafers patterned with metal and coated with oxide material were polished at different speeds and pressures. Our results show that it is possible to sense a change in the vibration signal over time during planarization of oxide material on patterned wafers. The horizontal accelerometer showed more sensitivity to change in vibration amplitude compared to the vertical accelerometer for a given polish condition. At low carrier and platen rotation rates, the change in vibration signal over time at fixed frequencies decreased approximately ½ - 1 order of magnitude (over the 2 to 10 psi polish pressure ranges). At high rotation speeds, the vibration signal remained essentially constant indicating that other factors dominated the vibration signaL These results show that while it is possible to sense changes in acceleration during polishing, more robust hardware and signal processing algorithms are required to ensure its use over a wide range of process conditions.

  6. Natural Gas Residual Fluids: Sources, Endpoints, and Organic Chemical Composition after Centralized Waste Treatment in Pennsylvania.

    PubMed

    Getzinger, Gordon J; O'Connor, Megan P; Hoelzer, Kathrin; Drollette, Brian D; Karatum, Osman; Deshusses, Marc A; Ferguson, P Lee; Elsner, Martin; Plata, Desiree L

    2015-07-21

    Volumes of natural gas extraction-derived wastewaters have increased sharply over the past decade, but the ultimate fate of those waste streams is poorly characterized. Here, we sought to (a) quantify natural gas residual fluid sources and endpoints to bound the scope of potential waste stream impacts and (b) describe the organic pollutants discharged to surface waters following treatment, a route of likely ecological exposure. Our findings indicate that centralized waste treatment facilities (CWTF) received 9.5% (8.5 × 10(8) L) of natural gas residual fluids in 2013, with some facilities discharging all effluent to surface waters. In dry months, discharged water volumes were on the order of the receiving body flows for some plants, indicating that surface waters can become waste-dominated in summer. As disclosed organic compounds used in high volume hydraulic fracturing (HVHF) vary greatly in physicochemical properties, we deployed a suite of analytical techniques to characterize CWTF effluents, covering 90.5% of disclosed compounds. Results revealed that, of nearly 1000 disclosed organic compounds used in HVHF, only petroleum distillates and alcohol polyethoxylates were present. Few analytes targeted by regulatory agencies (e.g., benzene or toluene) were observed, highlighting the need for expanded and improved monitoring efforts at CWTFs. PMID:26147419

  7. Characterization of Kinetic Binding Properties of Unlabeled Ligands via a Preincubation Endpoint Binding Approach.

    PubMed

    Shimizu, Yuji; Ogawa, Kazumasa; Nakayama, Masaharu

    2016-08-01

    The dissociation rates of unlabeled drugs have been well studied by kinetic binding analyses. Since kinetic assays are laborious, we developed a simple method to determine the kinetic binding parameters of unlabeled competitors by a preincubation endpoint assay. The probe binding after preincubation of a competitor can be described by a single equation as a function of time. Simulations using the equation revealed the degree of IC50 change induced by preincubation of a competitor depended on the dissociation rate koff of the competitor but not on the association rate kon To validate the model, an in vitro binding assay was performed using a smoothened receptor (SMO) and [(3)H]TAK-441, a SMO antagonist. The equilibrium dissociation constants (KI) and koff of SMO antagonists determined by globally fitting the model to the concentration-response curves obtained with and without 24 h preincubation correlated well with those determined by other methods. This approach could be useful for early-stage optimization of drug candidates by enabling determination of binding kinetics in a high-throughput manner because it does not require kinetic measurements, an intermediate washout step during the reaction, or prior determination of competitors' KI values. PMID:27270099

  8. Statistical identifiability and the surrogate endpoint problem, with application to vaccine trials

    PubMed Central

    2013-01-01

    Summary Given a randomized treatment Z, a clinical outcome Y, and a biomarker S measured some fixed time after Z is administered, we may be interested in addressing the surrogate endpoint problem by evaluating whether S can be used to reliably predict the effect of Z on Y. Several recent proposals for the statistical evaluation of surrogate value have been based on the framework of principal stratification. In this paper, we consider two principal stratification estimands: joint risks and marginal risks. Joint risks measure causal associations of treatment effects on S and Y, providing insight into the surrogate value of the biomarker, but are not statistically identifiable from vaccine trial data. While marginal risks do not measure causal associations of treatment effects, they nevertheless provide guidance for future research, and we describe a data collection scheme and assumptions under which the marginal risks are statistically identifiable. We show how different sets of assumptions affect the identifiability of these estimands; in particular, we depart from previous work by considering the consequences of relaxing the assumption of no individual treatment effects on Y before S is measured. Based on algebraic relationships between joint and marginal risks, we propose a sensitivity analysis approach for assessment of surrogate value, and show that in many cases the surrogate value of a biomarker may be hard to establish, even when the sample size is large. PMID:20105158

  9. An update on measurement and monitoring of cough: what are the important study endpoints?

    PubMed Central

    Spinou, Arietta

    2014-01-01

    Considerable progress has been achieved in the development of tools that assess cough. The visual analogue scale (VAS) for cough severity is widely used in clinical practice because it’s simple and practical. The Leicester cough questionnaire (LCQ) and the cough-specific quality of life questionnaire (CQLQ) are the most widely used health status questionnaires for adults with chronic cough. They are well validated for assessing the impact of cough. Cough can be assessed objectively with challenge tests that measure the sensitivity of the cough reflex. Cough challenge tests are better used to determine the mechanism of action of therapy, rather than efficacy. Cough frequency monitoring, the preferred tool to objectively assess cough, is increasingly being used as primary end-points in clinical trials. The most widely used cough monitors are the Leicester cough monitor (LCM) and VitaloJak. They are ambulatory devices that consist of a microphone and recording device. Cough frequency monitors do not reflect the intensity or the impact of cough; hence their relationship with subjective measures of cough is weak. Cough should therefore be assessed with a combination of subjective and objective tools. There is a paucity of studies that have investigated the minimal important difference of cough frequency monitors, rendering further investigations needed. PMID:25383207

  10. An update on measurement and monitoring of cough: what are the important study endpoints?

    PubMed

    Spinou, Arietta; Birring, Surinder S

    2014-10-01

    Considerable progress has been achieved in the development of tools that assess cough. The visual analogue scale (VAS) for cough severity is widely used in clinical practice because it's simple and practical. The Leicester cough questionnaire (LCQ) and the cough-specific quality of life questionnaire (CQLQ) are the most widely used health status questionnaires for adults with chronic cough. They are well validated for assessing the impact of cough. Cough can be assessed objectively with challenge tests that measure the sensitivity of the cough reflex. Cough challenge tests are better used to determine the mechanism of action of therapy, rather than efficacy. Cough frequency monitoring, the preferred tool to objectively assess cough, is increasingly being used as primary end-points in clinical trials. The most widely used cough monitors are the Leicester cough monitor (LCM) and VitaloJak. They are ambulatory devices that consist of a microphone and recording device. Cough frequency monitors do not reflect the intensity or the impact of cough; hence their relationship with subjective measures of cough is weak. Cough should therefore be assessed with a combination of subjective and objective tools. There is a paucity of studies that have investigated the minimal important difference of cough frequency monitors, rendering further investigations needed. PMID:25383207

  11. Using multi-walled carbon nanotubes (MWNTs) for oilfield produced water treatment with environmentally acceptable endpoints.

    PubMed

    Zaib, Qammer; Aina, Oluwajinmi Daniel; Ahmad, Farrukh

    2014-08-01

    In this study, multi-walled carbon nanotubes (MWNTs) were employed to remove benzene, toluene, ethylbenzene, and xylenes (BTEX) from low and high salinity water pre-equilibrated with crude oil. The treatment endpoint of crude oil-contaminated water is often controlled by BTEX compounds owing to their higher aqueous solubility and human-health toxicity compared to other hydrocarbons. The MWNT sorbent was extensively characterized and the depletion of the organic sorbate from the produced water was monitored by gas chromatography-mass spectrometry (GC-MS) and total organic carbon (TOC) analyses. The equilibrium sorptive removal of BTEX followed the order: ethylbenzene/o-xylene > m-xylene > toluene > benzene in the presence of other competing organics in produced water. Sorption mechanisms were explored through the application of a variety of kinetics and equilibrium models. Pseudo 2(nd) order kinetics and Freundlich equilibrium models were the best at describing BTEX removal from produced water. Hydrophobic interactions between the MWNTs and BTEX, as well as the physical characteristics of the sorbate molecules, were regarded as primary factors responsible for regulating competitive adsorption. Salinity played a critical role in limiting sorptive removal, with BTEX and total organic carbon (TOC) removal falling by 27% and 25%, respectively, upon the introduction of saline conditions. Results suggest that MWNTs are effective in removing risk-driving BTEX compounds from low-salinity oilfield produced water. PMID:24975808

  12. Clinical Trial Risk in Hepatitis C: Endpoint Selection and Drug Action

    PubMed Central

    Tillie, Nicole A.; Parker, Jayson L.; Feld, Jordan J.

    2016-01-01

    Background and Aims. This study analyzed the risk of clinical trial failure of new drugs for hepatitis C between January 1998 and January 2015. Methods. Hepatitis C drug development trials that were in phases I–III of clinical trial testing were obtained from the publicly accessible clinical trial repository and other publicly available databases. Drug compounds were excluded from the study if they began their phase I testing before 1998, if they were not industry sponsored, or if they treated secondary complications of hepatitis C. Clinical trial success rates were analyzed in comparison to industry expectations. Further analysis was conducted on the molecule classifications, the mechanisms of action, and the trial endpoints. Results. One hundred and twenty-three unique drug compounds were found to fulfill the inclusion criteria, eight of which had FDA approval. The overall cumulative pass rate for hepatitis C drugs was 20%, which is double the industry expectation rate. Viral inhibitor small molecule drugs significantly reduced the risk of drug failure during clinical trials compared to other mechanisms of action. Conclusion. On average, one in every five drugs that began clinical testing will be approved for market. Viral inhibitor small molecule drugs are the most promising and hold the least risk.

  13. Existence of the critical endpoint in the vector meson extended linear sigma model

    NASA Astrophysics Data System (ADS)

    Kovács, P.; Szép, Zs.; Wolf, Gy.

    2016-06-01

    The chiral phase transition of the strongly interacting matter is investigated at nonzero temperature and baryon chemical potential (μB) within an extended (2 +1 ) flavor Polyakov constituent quark-meson model that incorporates the effect of the vector and axial vector mesons. The effect of the fermionic vacuum and thermal fluctuations computed from the grand potential of the model is taken into account in the curvature masses of the scalar and pseudoscalar mesons. The parameters of the model are determined by comparing masses and tree-level decay widths with experimental values in a χ2-minimization procedure that selects between various possible assignments of scalar nonet states to physical particles. We examine the restoration of the chiral symmetry by monitoring the temperature evolution of condensates and the chiral partners' masses and of the mixing angles for the pseudoscalar η -η' and the corresponding scalar complex. We calculate the pressure and various thermodynamical observables derived from it and compare them to the continuum extrapolated lattice results of the Wuppertal-Budapest collaboration. We study the T -μB phase diagram of the model and find that a critical endpoint exists for parameters of the model, which give acceptable values of χ2.

  14. Clinical Trial Risk in Hepatitis C: Endpoint Selection and Drug Action.

    PubMed

    Tillie, Nicole A; Parker, Jayson L; Feld, Jordan J

    2016-01-01

    Background and Aims. This study analyzed the risk of clinical trial failure of new drugs for hepatitis C between January 1998 and January 2015. Methods. Hepatitis C drug development trials that were in phases I-III of clinical trial testing were obtained from the publicly accessible clinical trial repository and other publicly available databases. Drug compounds were excluded from the study if they began their phase I testing before 1998, if they were not industry sponsored, or if they treated secondary complications of hepatitis C. Clinical trial success rates were analyzed in comparison to industry expectations. Further analysis was conducted on the molecule classifications, the mechanisms of action, and the trial endpoints. Results. One hundred and twenty-three unique drug compounds were found to fulfill the inclusion criteria, eight of which had FDA approval. The overall cumulative pass rate for hepatitis C drugs was 20%, which is double the industry expectation rate. Viral inhibitor small molecule drugs significantly reduced the risk of drug failure during clinical trials compared to other mechanisms of action. Conclusion. On average, one in every five drugs that began clinical testing will be approved for market. Viral inhibitor small molecule drugs are the most promising and hold the least risk. PMID:27446855

  15. Early Proctoscopy is a Surrogate Endpoint of Late Rectal Toxicity in Prostate Cancer Treated With Radiotherapy

    SciTech Connect

    Ippolito, Edy; Massaccesi, Mariangela; Digesu, Cinzia; Deodato, Francesco; Macchia, Gabriella; Pirozzi, Giuseppe Antonio; Cilla, Savino; Cuscuna, Daniele; Di Lallo, Alessandra; Mattiucci, Gian Carlo; Mantini, Giovanna; Pacelli, Fabio; Valentini, Vincenzo; Cellini, Numa; Ingrosso, Marcello; Morganti, Alessio Giuseppe

    2012-06-01

    Purpose: To predict the grade and incidence of late clinical rectal toxicity through short-term (1 year) mucosal alterations. Methods and Materials: Patients with prostate adenocarcinoma treated with curative or adjuvant radiotherapy underwent proctoscopy a year after the course of radiotherapy. Mucosal changes were classified by the Vienna Rectoscopy Score (VRS). Late toxicity data were analyzed according to the Kaplan-Meier method. Comparison between prognosis groups was performed by log-rank analysis. Results: After a median follow-up time of 45 months (range, 18-99), the 3-year incidence of grade {>=}2 rectal late toxicity according to the criteria of the European Organization for Research and Treatment of Cancer and the Radiation Therapy Oncology Group was 24%, with all patients (24/24; 100%) experiencing rectal bleeding. The occurrence of grade {>=}2 clinical rectal late toxicity was higher in patients with grade {>=}2 (32% vs. 15 %, p = 0.02) or grade {>=}3 VRS telangiectasia (47% vs. 17%, p {<=} 0.01) and an overall VRS score of {>=}2 (31% vs. 16 %, p = 0.04) or {>=}3 (48% vs. 17%, p = 0.01) at the 1-year proctoscopy. Conclusions: Early proctoscopy (1 year) predicts late rectal bleeding and therefore can be used as a surrogate endpoint for late rectal toxicity in studies aimed at reducing this frequent complication.

  16. Controlling the duty cycle of holographic crossed gratings by in situ endpoint detection during development.

    PubMed

    Wang, Shiwei; Zeng, Lijiang

    2016-04-01

    A method of in situ development endpoint detection is proposed to control the duty cycle of holographic crossed gratings. Based on the observation that after the developer first touches the substrate surface the topography of the crossed grating undergoes an evolution process from a hole array of increasing diameter to a pillar array of decreasing diameter, we set up a development model. In this model, the shapes of both holes and pillars are assumed to have square in-plane cross sections, rotated 45° with respect to the main periodic directions, and straight side walls perpendicular to the grating plane. Thus, the main development process, including the transition from a hole array to a pillar array, can be characterized by a single parameter continuously, and the change of diffraction efficiency during the process can be theoretically calculated. Two different in situ development monitoring conditions were simulated and tested experimentally. Using this method, crossed gratings with various duty cycles were fabricated under different incident and monitoring conditions. PMID:27139670

  17. Ecotoxicological evaluation of carbamazepine using six different model systems with eighteen endpoints.

    PubMed

    Jos, A; Repetto, G; Rios, J C; Hazen, M J; Molero, M L; del Peso, A; Salguero, M; Fernández-Freire, P; Pérez-Martín, J M; Cameán, A

    2003-01-01

    The occurrence of pharmaceutically active compounds in the aquatic environment has been recognized as one of the emerging issues in environmental chemistry. However, the ecotoxicological effects of pharmaceuticals have still not been researched adequately. Carbamazepine, an anticonvulsant commonly present in surface and groundwater, was studied, using six ecotoxicological model systems with eighteen endpoints evaluated at different exposure time periods. The battery included the immobilization of Daphnia magna, bioluminescence inhibition in the bacterium Vibrio fischeri, growth inhibition of the alga Chlorella vulgaris, and micronuclei induction and root growth inhibition in the plant Allium cepa. Cell morphology, neutral red uptake, total protein content, MTS metabolization, lactate dehydrogenase leakage and activity and glucose-6-phosphate dehydrogenase activity were studied in the salmonid fish cell line RTG-2. The total protein content, LDH activity, neutral red uptake and MTT metabolization in Vero monkey kidney cells were also investigated. The most sensitive system to carbamazepine was the Vero cell line, followed by Chlorella vulgaris, Vibrio fischeri, Daphnia magna, Allium cepa, and RTG-2 cells. EC50 values from 19 microM in Vero cells at 72 h to more than 1200 microM in other systems, were obtained. Comparing the concentrations in water and the toxicity quantified in our assay systems, carbamazepine is not expected to produce acute toxic effects in the aquatic biota under these circumstances, but chronic and synergistic effects with other chemicals cannot be excluded. PMID:14599440

  18. Effect of the chiral chemical potential on the position of the critical endpoint

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Wang, Yong-Long; Cui, Zhu-Fang; Zong, Hong-Shi

    2015-02-01

    The effect of chiral imbalance on the QCD phase structure is studied in a framework of Dyson-Schwinger equations. It is found that the chiral phase transition is always a crossover in the T -μ5 plane when μ is 0 MeV or small values. The trail of the critical endpoints (CEPs) along with the variation of the chiral chemical potential is given. We find that the effect of μ5 is somewhat different from the existing chiral model calculations; namely, the CEP first moves roughly along the phase boundary of T -μ plane in a smaller μ direction, as in the chiral model calculations, but turns in the opposite direction to move away from the small chemical potential region, which has never been observed before. In addition, we also discuss the possibility of whether the study at finite temperature and chiral chemical potential can provide some useful information for the detection of the CEP at finite temperature and baryon chemical potential, since the former can be calculated in lattice QCD without the sign problem.

  19. End-Point Immobilization of Recombinant Thrombomodulin via Sortase-Mediated Ligation

    PubMed Central

    Jiang, Rui; Weingart, Jacob; Zhang, Hailong; Ma, Yong; Sun, Xue-Long

    2012-01-01

    We report an enzymatic end-point modification and immobilization of recombinant human thrombomodulin (TM), a cofactor for activation of anticoagulant protein C pathway via thrombin. First, a truncated TM mutant consisting of epidermal growth factor-like domains 4–6 (TM456) with a conserved pentapeptide LPETG motif at its C-terminal was expressed and purified in E. coli. Next, the truncated TM456 derivative was site-specifically modified with N-terminal diglycine containing molecules such as biotin and the fluorescent probe dansyl via sortase A (SrtA) mediated ligation (SML). The successful ligations were confirmed by SDS-PAGE and fluorescence imaging. Finally, the truncated TM456 was immobilized onto N-terminal diglycine-functionalized glass slide surface via SML directly. Alternatively, the truncated TM456 was biotinylated via SML and then immobilized onto streptavidin-functionalized glass slide surface indirectly. The successful immobilizations were confirmed by fluorescence imaging. The bioactivity of the immobilized truncated TM456 was further confirmed by protein C activation assay, in which enhanced activation of protein C by immobilized recombinant TM was observed. The sortase A-catalyzed surface ligation took place under mild conditions and is rapid occurring in a single step without prior chemical modification of the target protein. This site-specific covalent modification leads to molecules being arranged in a definitively ordered fashion and facilitating the preservation of the protein’s biological activity. PMID:22372933

  20. Phagocytosis in earthworms: An environmentally acceptable endpoint to assess immunotoxic potential of contaminated soils

    SciTech Connect

    Giggleman, M.A.; Fitzpatrick, L.C.; Goven, A.J.; Venables, B.J.; Callahan, C.A.

    1995-12-31

    Phagocytosis, a host-defense mechanism phylogenetically conserved throughout the animal kingdom, by earthworm (Lumbricus terrestris) coelomocytes has potential as a surrogate for vertebrates to be used as an environmentally acceptable endpoint to assess sublethal immunotoxic risks of contaminated soils to environmental (eg. higher wildlife) and public health. Coelomocytes can be exposed in vivo to complex contaminated parent soils by placing earthworms in situ at hazardous waste sites (HWS) or into soil samples and their dilutions with artificial soil (AS) in the laboratory, or in vitro to soil extracts and their fractionations. Here the authors report on phagocytosis by coelomocytes in earthworms exposed to pentachlorophenol (PCP) contaminated soils from a wood treatment HWS, PCP-spiked AS and PCP treated filter paper (FP). HWS soil was diluted to 25% with AS to a sublethal concentration (ca. 125 mg kg{sup {minus}1}) and earthworms exposed for 14d at 10 C under light conditions. AS was spiked at ca. 125 mg kg{sup {minus}1} PCP and earthworms were similarly exposed. Controls for both consisted of earthworms exposed to 100% AS. Earthworms were exposed to FP treated with a sublethal PCP concentration (15 {micro}g cm{sup {minus}2}) at 10 C under dark conditions for 96H. Controls were similarly exposed without PCP. Phagocytosis by coelomocytes in earthworms exposed to HWS soil, spiked AS and treated FP was suppressed 37, 41 and 29%, respectively. Results are discussed in terms of PCP body burdens and exposure protocols.