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diff --git a/public/presentations/in-silico-methods12/in-silico-methods.rst b/public/presentations/in-silico-methods12/in-silico-methods.rst new file mode 100644 index 0000000..33f5884 --- /dev/null +++ b/public/presentations/in-silico-methods12/in-silico-methods.rst @@ -0,0 +1,221 @@ +========================================= +In silico methods for toxicity prediction +========================================= + +:Author: Christoph Helma +:Affiliation: in silico toxicology gmbh +:Date: 2012-10-04 + +.. footer:: 2012-10-04 *in silico* toxicology gmbh + +Outline +======= + +.. class:: incremental + +- In silico toxicology methods +- Lazar framework +- Products and services + +In silico methods +================= +.. class:: incremental + +- Systems biology/molecular modeling +- Expert systems +- Data driven techniques + +Systems biology/molecular modeling +==================================== + +Model individual events (e.g. receptor interactions, (de)toxification) of the *adverse outcome pathway* + +.. class:: incremental small green + +- Mechanistic interpretation + +.. class:: incremental small red + +- Calculations/simulations may be very time consuming +- May require a lot of experimental data for parameterization +- Impossible to model mechanisms of complex toxicological endpoints + +Examples: VirtualToxLab/Biograf + +Expert systems +============== + +Formalize expert knowledge about chemicals and toxicity mechanisms and create a software program + +.. class:: incremental small green + +- Mechanistic interpretation + +.. class:: incremental small red + +- Model creation very time consuming +- Many toxicity mechanisms are poorly understood or even unknown +- Error prone and hard to validate (strong tendency towards overfitting) + +Examples: Derek/Lhasa + +Data driven +=========== + +Use all existing data for a particular endpoint and apply machine learning/QSAR algorithms in order to create a prediction model + +.. class:: incremental small green + +- Comparably fast +- Applicable for every endpoint with sufficient experimental data +- Sound validation possible + +.. class:: incremental small red + +- Applicability domain/model quality depends on experimental data +- Mechanistic relevance has to be extracted from models/descriptors/predictions + +Examples: Classical QSARs, Topkat, Multicase, lazar + +Lazy-Structure-Activity Relationships (lazar) +============================================= + +Automated read across predictions + +.. class:: incremental small + +- Find *similar* compounds (=neighbors) with measured activities +- Create a local (Q)SAR model with neighbors as training compounds +- Make a prediction with this model + +.. class:: incremental + +Lazar estimates the confidence (*applicability domain*) for each prediction + +Chemical Similarity +=================== + +Can be based on + +.. class:: incremental + +- Chemical structures +- Chemical properties +- Biological properties +- ... + +.. class:: incremental + +Lazar uses *activity specific similarities* + +Activity specific similarities +============================== + +Consider only *relevant* (i.e. statistically significant) substructures, properties, ... for similarity calculations + +Algorithms for finding relevant substructures (by A. Maunz): + +- Backbone refinement classes (BBRC) +- Latent structure mining (LAST) + +http://lazar.in-silico.ch +========================= + +.. image:: lazar-input.png + :height: 13em + :align: center + +http://lazar.in-silico.ch +========================= + +.. image:: lazar-output1.png + :height: 13em + :align: center + +http://lazar.in-silico.ch +========================= + +.. image:: lazar-output2.png + :height: 13em + :align: center + +http://lazar.in-silico.ch +========================= + +.. image:: lazar-output3.png + :height: 13em + :align: center + +Lazar limitations +================= + +.. class:: incremental + +- Model quality depends on data quality +- Applicability domain depends on learning instances + +in silico toxicology gmbh +========================= + +Open source software and algorithm development + +.. class:: incremental + +- Predictive toxicology and QSAR models +- Toxicological data mining +- Life science webservices and data warehouses + +Why open source? +================ + +.. class:: incremental + +- Clear and unambiguous documentation of implemented algorithms essential for scientific software (also required by many regulatory guidelines) +- Collaboration with partners, projects and external contributors +- Establishment of international standards +- Security of investment + +EU Research projects (FP6/7) +============================ + +.. class:: small + +:Sens-it-iv: Novel testing strategies for in vitro assessment of allergens +:Scarlet: Network on in silico methods for carcinogenicity and mutagenicity +:OpenTox: Open source framework for predictive toxicology +:ToxBank: Integrated data analysis and servicing of alternative testing methods in toxicology +:ModNanoTox: Modelling toxicity behaviour of engineered nanoparticles + +Free products and services +========================== + +:Lazar application: http://lazar.in-silico.ch +:OpenTox Webservices: http://webservices.in-silico.ch +:Source code: https://github.com/opentox + +Issue tracker, documentation, ... + +Commercial products and services +================================ + +.. class:: incremental + +- Lazar "software as a service" (SaaS): secure access for confidential predictions, batch predictions, ... +- Virtual appliances with lazar software for in-house/desktop installation +- Installation services +- Phone and email support + +Commercial products and services +================================ + +.. class:: incremental + +- Virtual toxicity screening of compounds and libraries +- Development of prediction models for new endpoints +- Scientific programming, contract research and consulting + +Contact +======= + +:Web: http://www.in-silico.ch +:Email: helma@in-silico.ch |