72 research outputs found

    Highlight report: Launch of a large integrated European in vitro toxicology project: EU-ToxRisk.

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    The integrated European project, EU-ToxRisk, proudly sees itself as "flagship" exploring new alternative-to-animal approaches to chemical safety evaluation. It promotes mechanism-based toxicity testing and risk assessment according to the principles laid down for toxicology for the twenty-first century. The project was officially launched in January 2016 with a kickoff meeting in Egmond aan Zee, the Netherlands. Over 100 scientists representing academia and industry as well as regulatory authorities attended the inaugural meeting. The project will integrate advances in in vitro and in silico toxicology, read-across methods, and adverse outcome pathways. EU-ToxRisk will continue to make use of the case study strategy deployed in SEURAT-1, a FP7 initiative ended in December 2015. Even though the development of new non-animal methods is one target of EU-ToxRisk, the project puts special emphasis on their acceptance and implementation in regulatory contexts. This €30 million Horizon 2020 project involves 38 European partners and one from the USA. EU-ToxRisk aims at the "development of a new way of risk assessment."Toxicolog

    Structural and functional characterization of an intradiol ring-cleavage dioxygenase from the polyphagous spider mite herbivore Tetranychus urticae Koch

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    Genome analyses of the polyphagous spider mite herbivore Tetranychus urticae (two-spotted spider mite) revealed the presence of a set of 17 genes that code for secreted proteins belonging to the "intradiol dioxygenase-like" subgroup. Phylogenetic analyses indicate that this novel enzyme family has been acquired by horizontal gene transfer. In order to better understand the role of these proteins in T. urticae, we have structurally and functionally characterized one paralog (tetur07g02040). It was demonstrated that this protein is indeed an intradiol ring-cleavage dioxygenase, as the enzyme is able to cleave catechol between two hydroxyl-groups using atmospheric dioxygen. The enzyme was characterized functionally and structurally. The active site of the T. urticae enzyme contains an Fe3+ cofactor that is coordinated by two histidine and two tyrosine residues, an arrangement that is similar to those observed in bacterial homologs. However, the active site is significantly more solvent exposed than in bacterial proteins. Moreover, the mite enzyme is monomeric, while almost all structurally characterized bacterial homologs form oligomeric assemblies. Tetur07g02040 is not only the first spider mite dioxygenase that has been characterized at the molecular level, but is also the first structurally characterized intradiol ring-cleavage dioxygenase originating from a eukaryote

    State-of-the-art of 3D cultures (organs-on-a-chip) in safety testing and pathophysiology.

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    Integrated approaches using different in vitro methods in combination with bioinformatics can (i) increase the success rate and speed of drug development; (ii) improve the accuracy of toxicological risk assessment; and (iii) increase our understanding of disease. Three-dimensional (3D) cell culture models are important building blocks of this strategy which has emerged during the last years. The majority of these models are organotypic, i.e., they aim to reproduce major functions of an organ or organ system. This implies in many cases that more than one cell type forms the 3D structure, and often matrix elements play an important role. This review summarizes the state of the art concerning commonalities of the different models. For instance, the theory of mass transport/metabolite exchange in 3D systems and the special analytical requirements for test endpoints in organotypic cultures are discussed in detail. In the next part, 3D model systems for selected organs--liver, lung, skin, brain--are presented and characterized in dedicated chapters. Also, 3D approaches to the modeling of tumors are presented and discussed. All chapters give a historical background, illustrate the large variety of approaches, and highlight up- and downsides as well as specific requirements. Moreover, they refer to the application in disease modeling, drug discovery and safety assessment. Finally, consensus recommendations indicate a roadmap for the successful implementation of 3D models in routine screening. It is expected that the use of such models will accelerate progress by reducing error rates and wrong predictions from compound testing

    Researchers’ attitudes to the 3Rs - An upturned hierarchy?

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    Animal use in biomedical research is generally justified by its potential benefits to the health of humans, or other animals, or the environment. However, ethical acceptability also requires scientists to limit harm to animals in their research. Training in laboratory animal science (LAS) helps scientists to do this by promoting best practice and the 3Rs. This study evaluated scientists’ awareness and application of the 3Rs, and their approach to other ethical issues in animal research. It was based on an online survey of participants in LAS courses held in eight venues in four European countries: Portugal (Porto, Braga), Germany (Munich, Heidelberg), Switzerland (Basel, Lausanne, Zurich), and Denmark (Copenhagen). The survey questions were designed to assess general attitudes to animal use in biomedical research, Replacement alternatives, Reduction and Refinement conflicts, and harm-benefit analysis. The survey was conducted twice: immediately before the course (‘BC’, N = 310) and as a follow-up six months after the course (‘AC’, N = 127). While courses do appear to raise awareness of the 3Rs, they had no measurable effect on the existing low level of belief that animal experimentation can be fully replaced by non-animal methods. Most researchers acknowledged ethical issues with their work and reported that they discussed these with their peers. The level of an animal’s welfare, and especially the prevention of pain, was regarded as the most pressing ethical issue, and as more important than the number of animals used or the use of animals as such. Refinement was considered more feasible than Replacement, as well as more urgent, and was also favoured over Reduction. Respondents in the survey reversed the ‘hierarchy’ of the 3Rs proposed by their architects, Russell and Burch, prioritizing Refinement over Reduction, and Reduction over Replacement. This ordering may conflict with the expectations of the public and regulators.</div

    Considering new methodologies in strategies for safety assessment of foods and food ingredients

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    Toxicology and safety assessment are changing and require new strategies for evaluating risk that are less depending on apical toxicity endpoints in animal models and relying more on knowledge of the mechanism of toxicity. This manuscript describes a number of developments that could contribute to this change and implement this in a stepwise roadmap that can be applied for the evaluation of food and food ingredients. The roadmap was evaluated in four case studies by using literature and existing data. This preliminary evaluation was shown to be useful. However, this experience should be extended by including examples where experimental work needs to be included. To further implement these new insights in toxicology and safety assessment for the area of food and food ingredients, the recommendation is that stakeholders take action in addressing gaps in our knowledge, e.g. with regard to the applicability of the roadmap for mixtures and food matrices. Further development of the threshold of toxicological concern is needed, as well as cooperation with other sectors where similar schemes are under development. Moreover, a more comprehensive evaluation of the roadmap, also including the identification of the need for in vitro experimental work is recommended.publishe

    The effect of intravenous aminophylline on stone free status after transureteral lithotripsy (TUL): a randomized double blind clinical trial study

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    Background: The third common urinary tract disease was renal stone, after the UTI and pathologic states of kidney. TUL is most useful and effective for removing the stones of inferior ureter. In other hand aminophylline can decrease urinary tract spasm. Then, combination of TUL and aminophylline help us to reduce the complication of TUL. Methods and materials: We have study on 87 case of renal colic who referred to Imam Khomeini hospital of sari and Tooba clinic. This study was a double blind systematic randomized clinical trial that patients were divided to two group as 1 and 2: group one includes patients who received aminophylline and group 2 were selected as our control samples. Our sample size was calculated by statistic analysis according to recent studies. Result: The average of TUL time was 5.12± 1.77 min in group 1 and 6.59± 3.47 min in group 2(p0.05). ESWL was used in one patient of group 1 because of remaining of stone, but 7 patients of group 2 did not response to Transureter lithotripsy, then they needed ESWL. Complication were not seen in patient who received Aminophylline and mean arterial pressure and heart rate was equal in two group. Conclusion: The difference of TUL Time between two groups was meaningful. As you know, aminophylline has an antispasmotic effect on urinary tract and tract with smooth muscle, and according to our finding, usage of aminophylline can reduce the complication of TUL and increase success rate of Lithotripsy in this patient. In other hand, it complications was few

    Effects of Integrated Weed Management on Forage Corn (Zea mays) in Miyaneh Region, Iran

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    As factorial experiment based on randomized complete block design with four replications was carried out to evaluate the effects of weed management on yield and components yield of corn silage in Miyaneh region in the summer of 2009. Treatments were cultivation (with and without), herbicides (Foramsulfuron, Nicosulfuron and 2,4-D+MCPA) and without controlling weed as control treatment. The results indicated that application of herbicides significantly influenced weeds dry weight at 1% probability level. The highest and lowest percentage loss of weeds dry weight were related to Foramsulfuron and 2,4-D+MCPA, respectively, which were significantly different from other herbicides (Nicosulfuron). Cultivation was significantly effective on weeds dry weight as compared with non cultivation treatment. The results, also, indicated that cultivation and herbicides significantly affected increasing the biological and grain yields compared to non weeds control treatment. The highest biological and grain yield increase were obtained by 59.1% and 57.2% due to cultivation treatment and by 51.8% and 58.2% due to Foramsulfuron herbicide application, respectively. The lowest biological and grain yield was obtained by application of Nicosulfuron herbicide which was statistically comparable to that of 2,4-D+MCPA herbicide treatment

    A roadmap for the development of alternative (non-animal) methods for systemic toxicity testing - t4 report

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    Systemic toxicity testing forms the cornerstone for the safety evaluation of substances. Pressures to move from traditional animal models to novel technologies arise from various concerns, including: the need to evaluate large numbers of previously untested chemicals and new products (such as nanoparticles or cell therapies), the limited predictivity of traditional tests for human health effects, duration and costs of current approaches, and animal welfare considerations. The latter holds especially true in the context of the scheduled 2013 marketing ban on cosmetic ingredients tested for systemic toxicity. Based on a major analysis of the status of alternative methods (Adler et al., 2011) and its independent review (Hartung et al., 2011), the present report proposes a roadmap for how to overcome the acknowledged scientific gaps for the full replacement of systemic toxicity testing using animals. Five whitepapers were commissioned addressing toxicokinetics, skin sensitization, repeated-dose toxicity, carcinogenicity, and reproductive toxicity testing. An expert workshop of 35 participants from Europe and the US discussed and refined these whitepapers, which were subsequently compiled to form the present report. By prioritizing the many options to move the field forward, the expert group hopes to advance regulatory science

    Radiation exposure of interventional cardiologists for different types of procedures in catheterization lab, is it more concern about extremities?

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    Introduction: Angiography and angioplasty expose cardiologists to a high level of X-ray comparing other radiographic methods, due to the high dose of radiation and the presence of the physician beside the patient bed during the procedure. Therefore, this study was designed to measure the absorbed dose in some important organs and extremities in cardiologists during different angiography and angioplasty procedures in catheterization lab. Methods: The entrance skin dose and extremity absorbed dose of the physicians in 100 angiography and angioplasty procedures were measured by TLD chips. The points on the physicians’ body, which were measured in this study, included: thyroid, right and left chest, right and left wrists, and left leg. The correlation of entrance skin dose in these six points to the exposure parameters is also evaluated. Results: The left leg has maximum dose and maximum correlation with total DAP for all three physicians in all procedure types. There was a weak correlation between left wrist absorbed dose and number of views among three physicians. Also, the maximum annual absorbed dose of the physicians in the left leg was lower than 150 mSv. Conclusion: According to the results of this study, it can be stated that periodic leg and hand dosimetry during operation is necessary for interventional cardiologists. Results also showed that, regardless of the type of procedure, the characteristics of device output, especially DAP, have a direct role in the absorbed dose of the organs and extremities, especially those outside the shield
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