9 research outputs found

    A framework for grouping and read-across of nanomaterials- supporting innovation and risk assessment

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    According to some legislation grouping can streamline data gap filling for the hazard assessment of substances. The GRACIOUS Framework aims to facilitate the application of grouping of nanomaterials or nanoforms (NFs), in a regulatory context and to support innovation. This includes using grouping to enable read-across from (a) source(s), for which data and information exist, to a similar target NF where information is lacking. The Framework provides an initial set of hypotheses for the grouping of NFs which take into account the identity and use(s) of the NFs, as well as the purpose of grouping. Initial collection of basic information allows selection of an appropriate pre-defined grouping hypothesis and a tailored Integrated Approach to Testing and Assessment (IATA), designed to generate new evidence to support acceptance or rejection of the hypothesis. Users needing to develop their own user-defined hypothesis (and IATA) are also supported by the Framework. In addition, the IATA guides acquisition of the information needed to support read-across. This approach gathers information to render risk assessment more efficient, affordable, as well as reducing the use of test animals

    The potential of platinum-DNA adduct determination in ex vivo treated tumor fragments for the prediction of sensitivity to cisplatin chemotherapy

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    Background: Response to cisplatin-therapy is assumed to be related to the formation of platinum (Pt)-DNA adducts. Measurement of these adducts prior to therapy could be of value to improve cisplatin based cancer therapy. Materials and methods: We determined Pt-GG and Pt-AG adduct levels by use of 32P-postlabeling after ex vivo cisplatin treatment of fragments of head and neck squamous cell carcinoma (HNSCC) xenografts (five lines), and of tumor biopsies from patients with HNSCC (n = 8) and testicular cancer (n = 8). Results: Adduct levels in fragments (3 x 3 x 3 mm) exposed to 10 to 80 μM cisplatin for one hour, showed positive correlations with the in vivo response to cisplatin treatment (P < 0.05), as well as with the xenograft adduct levels observed after in vivo cisplatin treatment (P < 0.02). After an additional five-hour drug-free incubation period the correlations were absent. When patient tumor fragments were exposed ex vivo to 80 μM cisplatin for one hour, adduct levels were similar in HNSCC and testicular cancer. Persistence of adducts was observed for testicular cancer in the additional drug-free period. The adduct levels in the samples of two HNSCC patients who received cisplatin chemotherapy were in line with the hypothesis that higher adduct levels are associated with a better response. Conclusion: Our preliminary results show that analysis of DNA adducts following ex vivo drug treatment is a feasible approach towards a predictive assay, which warrants further investigation

    A comprehensive assessment protocol including patient reported outcomes, physical tests, and biological sampling in newly diagnosed patients with head and neck cancer: is it feasible?

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    Purpose Large cohort studies are needed taking into account cancer-related, personal, biological, psychobehavioral, and lifestyle-related factors, to guide future research to improve treatment and supportive care. We aimed to evaluate the feasibility of a comprehensive baseline assessment of a cohort study evaluating the course of quality of life (QoL). Methods newly diagnosed head and neck cancer (HNC) patients were asked to participate. Assessments consisted of questionnaires (635 items), a home visit (including a psychiatric interview, physical tests, and blood and saliva collection), and tissue collection. Representativeness of the study sample was evaluated by comparing demographics, clinical factors, depression, anxiety, and QoL between responders and nonresponders. Feasibility was evaluated covering the number of questions, time investment, intimacy, and physical burden. Results During the inclusion period (4 months), 15 out of 26 (60%) patients agreed to participate. Less women participated, 13%in responders group versus 63%in non-responders group (p=0.008). No other differences were found between responders and non-responders. Responders completed more than 95% of the questionnaires’ items and rated the number of questions, time investment and intimacy as feasible, and the physical and psychological burden as low. It took on average 3 h to complete the questionnaires and 1.5 h for the home visit. Conclusions This study reveals that a comprehensive assessment including various questionnaires, physical measurements, and biological assessments is feasible according to patients with newly diagnosed HNC. A large prospective cohort study has started aiming to include 739 HNC patients and their informal caregivers in the Netherlands

    Mitochondria-Targeted Drugs

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