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Workshop Progress on alternative in vitromethods for safety 
assessment of chemicals and their impact on human health: 
international and Brazilian views
Vanessa Rocha, Ph.D.
Scientific Manager- Natura Inovação
04.01.15
Challenges on use 
alternative methods for 
skin sensitization
TOPICS
• ALLERGIC CONTACT DERMATITIS AND CELLULAR ALLERGIC CONTACT DERMATITIS AND CELLULAR ALLERGIC CONTACT DERMATITIS AND CELLULAR ALLERGIC CONTACT DERMATITIS AND CELLULAR 
PATHWAYS ON SKIN SENSITISATIONPATHWAYS ON SKIN SENSITISATIONPATHWAYS ON SKIN SENSITISATIONPATHWAYS ON SKIN SENSITISATION
• REGULATORY CONTEXTREGULATORY CONTEXTREGULATORY CONTEXTREGULATORY CONTEXT
• ALTERNATIVE METHODS FOR SKIN SENSITIZATIONALTERNATIVE METHODS FOR SKIN SENSITIZATIONALTERNATIVE METHODS FOR SKIN SENSITIZATIONALTERNATIVE METHODS FOR SKIN SENSITIZATION
• INTEGRATED TESTING STRATEGIESINTEGRATED TESTING STRATEGIESINTEGRATED TESTING STRATEGIESINTEGRATED TESTING STRATEGIES
• CONCLUSIONSCONCLUSIONSCONCLUSIONSCONCLUSIONS
2nd Exposure
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InflammationInflammationInflammationInflammation, CD8+T, CD8+T, CD8+T, CD8+T----Cells, Cells, Cells, Cells, 
keratinocytekeratinocytekeratinocytekeratinocyte apoptosisapoptosisapoptosisapoptosis
1st Exposure
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1111ststststContactContactContactContact
No No No No ClinicalClinicalClinicalClinical manifestationsmanifestationsmanifestationsmanifestations
Allergic Contact Dermititis
HowHowHowHow wewewewe developdevelopdevelopdevelop allergyallergyallergyallergy totototo aaaa substance?substance?substance?substance?
Allergic Allergic Allergic Allergic 
Contact Contact Contact Contact 
Dermatitis is Dermatitis is Dermatitis is Dermatitis is 
an immune an immune an immune an immune 
mediated mediated mediated mediated 
disease, disease, disease, disease, 
specific to specific to specific to specific to 
the chemical the chemical the chemical the chemical 
introducedintroducedintroducedintroduced
Regulatory Context
SkinSkinSkinSkin sensitizationsensitizationsensitizationsensitization isisisis consideredconsideredconsideredconsidered totototo bebebebe oneoneoneone ofofofof thethethethe keykeykeykey humanhumanhumanhuman healthhealthhealthhealth
endpointsendpointsendpointsendpoints ofofofof toxicologicaltoxicologicaltoxicologicaltoxicological assessmentassessmentassessmentassessment.... TheTheTheThe potentialpotentialpotentialpotential ofofofof chemicalchemicalchemicalchemical hashashashas
traditionallytraditionallytraditionallytraditionally beenbeenbeenbeen evaluatedevaluatedevaluatedevaluated using animal tests
• GuineaGuineaGuineaGuinea----pig based test pig based test pig based test pig based test ---- OECD 406OECD 406OECD 406OECD 406
• MouseMouseMouseMouse----based local lymph node assay (LLNA) based local lymph node assay (LLNA) based local lymph node assay (LLNA) based local lymph node assay (LLNA) –––– OECD 429 (or OECD 442 A OECD 429 (or OECD 442 A OECD 429 (or OECD 442 A OECD 429 (or OECD 442 A 
+ B) + B) + B) + B) –––– a standa standa standa stand----alone test which use less animals than others guidelines alone test which use less animals than others guidelines alone test which use less animals than others guidelines alone test which use less animals than others guidelines 
OECD OECD OECD OECD (see also (see also (see also (see also http://iccvam.niehs.nih.gov)
Regulatory Context
LLNALLNALLNALLNA OECDOECDOECDOECD 429429429429 PROTOCOLPROTOCOLPROTOCOLPROTOCOL
SlideSlideSlideSlide fromfromfromfrom ProfProfProfProf MarcMarcMarcMarc PallardyPallardyPallardyPallardy,,,, UniversitéUniversitéUniversitéUniversité ParisParisParisParis----SudSudSudSud
Quantitative test for predicting the Quantitative test for predicting the Quantitative test for predicting the Quantitative test for predicting the 
sensitizing potentialsensitizing potentialsensitizing potentialsensitizing potential of a chemical of a chemical of a chemical of a chemical 
(Hazard identification) (Hazard identification) (Hazard identification) (Hazard identification) 
Positive result if SI>3 for any single Positive result if SI>3 for any single Positive result if SI>3 for any single Positive result if SI>3 for any single 
treatmenttreatmenttreatmenttreatment
Regulatory Context
HAZARDHAZARDHAZARDHAZARD IDENTIFICATIONIDENTIFICATIONIDENTIFICATIONIDENTIFICATION ANDANDANDAND CLASSIFICATIONCLASSIFICATIONCLASSIFICATIONCLASSIFICATION ONONONON GLOBALGLOBALGLOBALGLOBAL HARMONIZEDHARMONIZEDHARMONIZEDHARMONIZED
SYSTEMSYSTEMSYSTEMSYSTEM (GHS)(GHS)(GHS)(GHS)
Alternative Methods for
SKIN SENSITIZATION
Adverse Outcome Pathway (AOP) for Adverse Outcome Pathway (AOP) for Adverse Outcome Pathway (AOP) for Adverse Outcome Pathway (AOP) for 
Skin Sensitization by OECD Skin Sensitization by OECD Skin Sensitization by OECD Skin Sensitization by OECD 
ElicitationElicitationElicitationElicitation PhasePhasePhasePhase
- CDCDCDCD8888++++ TTTT----CellsCellsCellsCells
- RegulatoryRegulatoryRegulatoryRegulatory TTTT----CellsCellsCellsCells
SensitizationSensitizationSensitizationSensitization PhasePhasePhasePhase
- DangerDangerDangerDanger signalssignalssignalssignals (direct(direct(direct(direct andandandand indirect/proindirect/proindirect/proindirect/pro----inflammatoryinflammatoryinflammatoryinflammatory
signalssignalssignalssignals bybybyby keratinocytes)keratinocytes)keratinocytes)keratinocytes)
- DendriticDendriticDendriticDendritic cellcellcellcell activation,activation,activation,activation, migrationmigrationmigrationmigration andandandand maturationmaturationmaturationmaturation
- HaptenHaptenHaptenHapten presentationpresentationpresentationpresentation totototo TTTT----CellsCellsCellsCells inininin thethethethe drainingdrainingdrainingdraining lymphlymphlymphlymph
nodenodenodenode
- TTTT----lymphocytelymphocytelymphocytelymphocyte activationactivationactivationactivation andandandand proliferationproliferationproliferationproliferation ofofofof memorymemorymemorymemory
cellscellscellscells
PrePrePrePre----immunologicalimmunologicalimmunologicalimmunological phasephasephasephase
- SkinSkinSkinSkin penetrationpenetrationpenetrationpenetration
- ChemicalChemicalChemicalChemical reactivity/covalentreactivity/covalentreactivity/covalentreactivity/covalent bindingbindingbindingbinding totototo skinskinskinskin proteinproteinproteinprotein
- SkinSkinSkinSkin MetabolismMetabolismMetabolismMetabolism
What are the steps leading to 
chemical allergy?
Induction fase of Skin sensitisationKaplan et al, 2012. Nature reviews
Induction fase of Skin sensitisation
Kaplan et al, 2012. Nature 
reviews
PrePrePrePre----immunologicalimmunologicalimmunologicalimmunological phasephasephasephase
- SkinSkinSkinSkin penetrationpenetrationpenetrationpenetration
- ChemicalChemicalChemicalChemical reactivity/covalentreactivity/covalentreactivity/covalentreactivity/covalent bindingbindingbindingbinding totototo skinskinskinskin proteinproteinproteinprotein
- SkinSkinSkinSkin MetabolismMetabolismMetabolismMetabolism
What are the steps leading to 
chemical allergy?
CHEMICAL REACTIVITY
QSARsQSARsQSARsQSARs (Free(Free(Free(Free orororor commercial)commercial)commercial)commercial)
Software which identify chemicals toxicity
- OECDOECDOECDOECD QSARQSARQSARQSAR ToolboxToolboxToolboxToolbox (free)(free)(free)(free)
- DerekDerekDerekDerek®®®®,,,,TimessTimessTimessTimess®®®® (commercial)(commercial)(commercial)(commercial)
- ManyManyManyMany othersothersothersothers…………
DirectDirectDirectDirect PeptidePeptidePeptidePeptide ReactivityReactivityReactivityReactivity AssayAssayAssayAssay (DPRA)(DPRA)(DPRA)(DPRA)
---- ValidatedValidatedValidatedValidated bybybyby ECVAMECVAMECVAMECVAM –––– OECDOECDOECDOECD 442442442442CCCC
DPRA ChemicalDPRA ChemicalDPRA ChemicalDPRA Chemical----Protein ReactivityProtein ReactivityProtein ReactivityProtein Reactivity
Readout for the DPRA: peptide depletionReadout forthe DPRA: peptide depletionReadout for the DPRA: peptide depletionReadout for the DPRA: peptide depletion
Readout for the DPRA: peptide depletionReadout for the DPRA: peptide depletionReadout for the DPRA: peptide depletionReadout for the DPRA: peptide depletion
Depleted peak of
parent peptide
CHEMICAL REACTIVITY
DirectDirectDirectDirect PeptidePeptidePeptidePeptide ReactivityReactivityReactivityReactivity AssayAssayAssayAssay (DPRA)(DPRA)(DPRA)(DPRA)
---- ValidatedValidatedValidatedValidated bybybyby ECVAMECVAMECVAMECVAM –––– OECDOECDOECDOECD 442442442442CCCC
CHEMICAL REACTIVITY
DirectDirectDirectDirect PeptidePeptidePeptidePeptide ReactivityReactivityReactivityReactivity AssayAssayAssayAssay (DPRA)(DPRA)(DPRA)(DPRA)
---- ValidatedValidatedValidatedValidated bybybyby ECVAMECVAMECVAMECVAM –––– OECDOECDOECDOECD 442442442442CCCC
ECVAM Recommendation on the DPRA (Nov 2013)ECVAM Recommendation on the DPRA (Nov 2013)ECVAM Recommendation on the DPRA (Nov 2013)ECVAM Recommendation on the DPRA (Nov 2013)
http://ihcp.jrc.ec.europa.eu/our_labs/eurl-ecvam/eurl-ecvam-recommendations/files-dpra/EURL_ECVAM_Recommendation_DPRA_2013.pdf
ElicitationElicitationElicitationElicitation PhasePhasePhasePhase
- CDCDCDCD8888++++ TTTT----CellsCellsCellsCells
- RegulatoryRegulatoryRegulatoryRegulatory TTTT----CellsCellsCellsCells
SensitizationSensitizationSensitizationSensitization PhasePhasePhasePhase
- DangerDangerDangerDanger signalssignalssignalssignals (direct(direct(direct(direct andandandand indirect/proindirect/proindirect/proindirect/pro----inflammatoryinflammatoryinflammatoryinflammatory
signalssignalssignalssignals bybybyby keratinocytes)keratinocytes)keratinocytes)keratinocytes)
- DendriticDendriticDendriticDendritic cellcellcellcell activation,activation,activation,activation, migrationmigrationmigrationmigration andandandand maturationmaturationmaturationmaturation
- HaptenHaptenHaptenHapten presentationpresentationpresentationpresentation totototo TTTT----CellsCellsCellsCells inininin thethethethe drainingdrainingdrainingdraining lymphlymphlymphlymph
nodenodenodenode
- TTTT----lymphocytelymphocytelymphocytelymphocyte activationactivationactivationactivation andandandand proliferationproliferationproliferationproliferation ofofofof memorymemorymemorymemory
cellscellscellscells
PrePrePrePre----immunologicalimmunologicalimmunologicalimmunological phasephasephasephase
- SkinSkinSkinSkin penetrationpenetrationpenetrationpenetration
- ChemicalChemicalChemicalChemical reactivity/covalentreactivity/covalentreactivity/covalentreactivity/covalent bindingbindingbindingbinding totototo skinskinskinskin proteinproteinproteinprotein
- SkinSkinSkinSkin MetabolismMetabolismMetabolismMetabolism
What are the steps leading to 
chemical allergy?
CELL BASED ASSAYS
• KeratinocyteKeratinocyteKeratinocyteKeratinocyte assaysassaysassaysassays addressingaddressingaddressingaddressing chemicalchemicalchemicalchemical reactivityreactivityreactivityreactivity:::: NrfNrfNrfNrf----2222
- KeratinoSensKeratinoSensKeratinoSensKeratinoSensTMTMTMTM ((((HaCatHaCatHaCatHaCat humanhumanhumanhuman KeratinocyteKeratinocyteKeratinocyteKeratinocyte cellcellcellcell linelinelineline –––– GivaudanGivaudanGivaudanGivaudan))))
ValidatedValidatedValidatedValidated bybybyby ECVAMECVAMECVAMECVAM andandandand adoptedadoptedadoptedadopted bybybyby OECDOECDOECDOECD 442442442442DDDD))))
- LuSensLuSensLuSensLuSens ((((HaCatHaCatHaCatHaCat humanhumanhumanhuman KeratinocyteKeratinocyteKeratinocyteKeratinocyte cellcellcellcell linelinelineline ---- BASFBASFBASFBASF))))
- AreAreAreAre cccc32323232 cellcellcellcell linelinelineline assayassayassayassay ((((CXRCXRCXRCXR BioscienceBioscienceBioscienceBioscience))))
• KeratinocyteKeratinocyteKeratinocyteKeratinocyte assaysassaysassaysassays addressingaddressingaddressingaddressing inflammationinflammationinflammationinflammation
- ILILILIL----18181818 assayassayassayassay:::: humanhumanhumanhuman keratinocytekeratinocytekeratinocytekeratinocyte cellcellcellcell linelinelineline NNNNCTCCTCCTCCTC 2544254425442544 (University(University(University(University ofofofof
Milan)Milan)Milan)Milan)
- EpidermalEpidermalEpidermalEpidermal EquivalentEquivalentEquivalentEquivalent (EE)(EE)(EE)(EE) potencypotencypotencypotency assayassayassayassay (VU(VU(VU(VU UniversityUniversityUniversityUniversity MedicalMedicalMedicalMedical
Centre)Centre)Centre)Centre)
• 12 concentration 
• Incubation for 48 h
• Cell lysis/luciferase substrate
• Cell viability MTT
KeratinoSensKeratinoSensKeratinoSensKeratinoSensTMTMTMTM
Readout for the Readout for the Readout for the Readout for the KeratinoSensKeratinoSensKeratinoSensKeratinoSensTMTMTMTM
A test substance is considered sensitizer if: Imax shows a >1.5 fold gene induction; this induction 
is statistically significant above the solvent control value; The IC1.5 value is below 1000 uM in at 
least two of three repetitions and cell viability needs to be above 70%
KeratinoSens Partnership Natura and Givaudan
KeratinoSens Partnership Natura and Givaudan
KeratinoSensTM use for mixtures –
Partnership Natura and Givaudan
First publication testing complex mixtures in the 
KeratinoSensTM (natural ingredients)
This study was used by Givaudan during the process of 
validation by ECVAM
ECVAM Recommendation on the ECVAM Recommendation on the ECVAM Recommendation on the ECVAM Recommendation on the KeratinoSensKeratinoSensKeratinoSensKeratinoSens (Feb (Feb (Feb (Feb 
2014)2014)2014)2014)
http://ihcp.jrc.ec.europa.eu/our_labs/eurl-ecvam/eurl-ecvam-recommendations/files-dpra/EURL_ECVAM_Recommendation_DPRA_2013.pdf
CELL BASED ASSAYS
• DendriticDendriticDendriticDendritic cellcellcellcell assaysassaysassaysassays andandandand DendriticDendriticDendriticDendritic----likelikelikelike cellcellcellcell assaysassaysassaysassays
• CellCellCellCell lineslineslineslines
- THPTHPTHPTHP----1111 HumanHumanHumanHuman cellcellcellcell linelinelineline activationactivationactivationactivation testtesttesttest (h(h(h(h----CLAT,CLAT,CLAT,CLAT, KaoKaoKaoKao andandandand ShiseidoShiseidoShiseidoShiseido)))) ––––
draftdraftdraftdraft guidelineguidelineguidelineguideline OECDOECDOECDOECD
- UUUU937937937937 MyeloidMyeloidMyeloidMyeloid UUUU937937937937 skinskinskinskin sensitizationsensitizationsensitizationsensitization testtesttesttest (MUSST,(MUSST,(MUSST,(MUSST, LLLL ´́́́OréalOréalOréalOréal;;;; BASFBASFBASFBASF))))
- MUTZMUTZMUTZMUTZ----3333 ((((SENSSENSSENSSENS----ITITITIT----IVIVIVIV consor tiumconsor tiumconsor tiumconsor tium))))
• HumanHumanHumanHuman dendriticdendriticdendriticdendritic cellscellscellscells
---- PeripheralPeripheralPeripheralPeripheral bloodbloodbloodblood monocytemonocytemonocytemonocyte----derivedderivedderivedderived dendriticdendriticdendriticdendritic cellcellcellcell assayassayassayassay (PBMDC,(PBMDC,(PBMDC,(PBMDC,
BeiersdorfBeiersdorfBeiersdorfBeiersdorf))))
- CDCDCDCD34343434 –––– DCDCDCDC::::VITOSENSVITOSENSVITOSENSVITOSENS ((((VITOVITOVITOVITO))))
HumanHumanHumanHuman----CellCellCellCell LineLineLineLine ActivationActivationActivationActivation Test (hTest (hTest (hTest (h----CLAT)CLAT)CLAT)CLAT)
2010 Ashikaga et al. A comparative evaluation of in vitro skin sensitisation tests: The Human 
Cell-line Activation Test (h-CLAT) versus The Local Lymph Node Assay. ATLA
ReadoutReadoutReadoutReadout for for for for thethethethe hhhh----CLATCLATCLATCLAT
Skin sensitizer identification by IL-8 secretion and 
CD86 expression on THP-1 cells
Carolina Bellini PariseCarolina Bellini PariseCarolina Bellini PariseCarolina Bellini Parise1111, , , , Vanessa Moura SáVanessa Moura SáVanessa Moura SáVanessa Moura Sá----RochaRochaRochaRocha2222 andandandand Jane Zveiter de Jane Zveiter de Jane Zveiter de Jane Zveiter de MoraesMoraesMoraesMoraes1111
Submitted to Submitted to Submitted to Submitted to AltexAltexAltexAltex 2015201520152015
CD86IL-8
Carolina Bellini PariseCarolina Bellini PariseCarolina Bellini PariseCarolina BelliniParise1111, , , , Vanessa Moura SáVanessa Moura SáVanessa Moura SáVanessa Moura Sá----RochaRochaRochaRocha2222 andandandand Jane Zveiter de Jane Zveiter de Jane Zveiter de Jane Zveiter de MoraesMoraesMoraesMoraes1111
Submitted to Submitted to Submitted to Submitted to AltexAltexAltexAltex 2015201520152015
Skin sensitizer identification by IL-8 secretion and 
CD86 expression on THP-1 cells
Skin Sensitization in 3Skin Sensitization in 3Skin Sensitization in 3Skin Sensitization in 3----D ModelD ModelD ModelD Model
Potency estimationPotency estimationPotency estimationPotency estimation
• Tissue: Tissue: Tissue: Tissue: EpiDermTMEpiDermTMEpiDermTMEpiDermTM ((((MatTekMatTekMatTekMatTek EpiDermEpiDermEpiDermEpiDerm System) System) System) System) 
• 6 concentration 6 concentration 6 concentration 6 concentration 
• Incubation for 24 hIncubation for 24 hIncubation for 24 hIncubation for 24 h
• Evaluation of GSH (depletion), cell viability (percentage Evaluation of GSH (depletion), cell viability (percentage Evaluation of GSH (depletion), cell viability (percentage Evaluation of GSH (depletion), cell viability (percentage 
viable) and viable) and viable) and viable) and Gene expression Gene expression Gene expression Gene expression (fold change relative to (fold change relative to (fold change relative to (fold change relative to 
controls)controls)controls)controls)
• Report combine these results using a proprietary Report combine these results using a proprietary Report combine these results using a proprietary Report combine these results using a proprietary 
algorism and provide an algorism and provide an algorism and provide an algorism and provide an In Vitro Toxicity Index In Vitro Toxicity Index In Vitro Toxicity Index In Vitro Toxicity Index (TI)(TI)(TI)(TI)
Skin Sensitization in 3Skin Sensitization in 3Skin Sensitization in 3Skin Sensitization in 3----D ModelD ModelD ModelD Model
Past
Hazard Assessment with animal test
1end-point = 1test
Hazard Assessment with non-animal test
1 end-point = MANY 
TESTS!!
FRAGMENTATIONPresent
Consesus among Scientific community is that only one single non-animal test might not be 
sufficient as a stand-alone method to cover the endpoint skin sensitization
Integrated testing strategy is need
How to integrate the results?
Adverse Outcome Pathway – OECD
Adverse outcome pathway Adverse outcome pathway Adverse outcome pathway Adverse outcome pathway ---- ECVAM ECVAM ECVAM ECVAM 
How to integrate the results?
Combining Key events
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How to integrate these data?
Integrated Testing Strategies - BASF
How to integrate these data?
Integrated Testing Strategies - BASF
Integrated Testing Strategies 
Predictive of assays and Combinations
How to integrate these data?How to integrate these data?How to integrate these data?How to integrate these data?
Integrated Testing Strategies Integrated Testing Strategies Integrated Testing Strategies Integrated Testing Strategies ---- KAO KAO KAO KAO 
Integrated Testing Strategies 
Potency estimation
MIT: Minimum Induction Threshold
Urbisch, D., et al. Assessing skin sensitization hazard in mice and men
using non animal test methods. Regul.Toxicol. Pharmacol. (2015)
‘2 out of 3’: DPRA, keratinoSensTM and h-CLAT (Bauch et al, 2012)
Results should also be considered by applicability domains:
• Shiff base formers, Michael acceptors, substances reacting in nucleophilic
substitutions, quinone precursors….
• or UV‐filters, preservatives, hair dyes…
Integrated Testing Strategies 
Potency estimation
Integrated Testing Strategies 
Potency estimation
CONCLUSIONSCONCLUSIONSCONCLUSIONSCONCLUSIONS
• OECDOECDOECDOECD hashashashas defineddefineddefineddefined aaaa AOPAOPAOPAOP forforforfor skinskinskinskin sensitisationsensitisationsensitisationsensitisation
• 3333 methodsmethodsmethodsmethods hashashashas beenbeenbeenbeen validatedvalidatedvalidatedvalidated bybybyby ECVAMECVAMECVAMECVAM ((((DPRA,DPRA,DPRA,DPRA, KeratinoSensKeratinoSensKeratinoSensKeratinoSens TMTMTMTM,,,, hhhh----CLATCLATCLATCLAT))))
andandandand cancancancan bebebebe usedusedusedused inininin combinationcombinationcombinationcombination withwithwithwith otherotherotherother informationinformationinformationinformation.... HoweverHoweverHoweverHowever theretheretherethere areareareare
manymanymanymany othersothersothersothers methodsmethodsmethodsmethods availableavailableavailableavailable atatatat market,market,market,market, thatthatthatthat shouldshouldshouldshould bebebebe evaluatedevaluatedevaluatedevaluated bybybyby ECVAMECVAMECVAMECVAM
• TheTheTheThe methodsmethodsmethodsmethods evaluatedevaluatedevaluatedevaluated reflectreflectreflectreflect hazardshazardshazardshazards conditionsconditionsconditionsconditions asasasas 100100100100%%%% skinskinskinskin penetrationpenetrationpenetrationpenetration
(worst(worst(worst(worst casecasecasecase)))) andandandand notnotnotnot observedobservedobservedobserved frequentlyfrequentlyfrequentlyfrequently atatatat realrealrealreal lifelifelifelife
• ThereThereThereThere isisisis aaaa needneedneedneed totototo improveimproveimproveimprove methodsmethodsmethodsmethods forforforfor highlyhighlyhighlyhighly lipophiliclipophiliclipophiliclipophilic substancessubstancessubstancessubstances orororor solidssolidssolidssolids
asasasas wellwellwellwell asasasas metabolicmetabolicmetabolicmetabolic activationactivationactivationactivation
• ThereThereThereThere isisisis aaaa needneedneedneed totototo improveimproveimproveimprove thethethethe predictivepredictivepredictivepredictive ofofofof potencypotencypotencypotency andandandand notnotnotnot onlyonlyonlyonly hazardhazardhazardhazard
(Projects(Projects(Projects(Projects usingusingusingusing newnewnewnew mathematicalmathematicalmathematicalmathematical approachesapproachesapproachesapproaches totototo evaluateevaluateevaluateevaluate thethethethe relevancerelevancerelevancerelevance
(Recursive(Recursive(Recursive(Recursive FeatureFeatureFeatureFeature Elimination)Elimination)Elimination)Elimination) andandandand combinecombinecombinecombine datadatadatadata (Hidden(Hidden(Hidden(Hidden MarkovMarkovMarkovMarkov Model,Model,Model,Model,
BayesianBayesianBayesianBayesian Network)Network)Network)Network) areareareare onononon goinggoinggoinggoing bybybyby CAAT,CAAT,CAAT,CAAT, NationalNationalNationalNational ToxicologyToxicologyToxicologyToxicology ProgramProgramProgramProgram andandandand
ICCVAMICCVAMICCVAMICCVAM (USA(USA(USA(USA))))
• NoneNoneNoneNone ofofofof thesethesethesethese assaysassaysassaysassays areareareare availableavailableavailableavailable inininin BrazilBrazilBrazilBrazil.... IniciativesIniciativesIniciativesIniciatives totototo delevopdelevopdelevopdelevop skinskinskinskin
sensitizationsensitizationsensitizationsensitization modelsmodelsmodelsmodels hashashashas beenbeenbeenbeen mademademademade bybybyby UnifespUnifespUnifespUnifesp,,,, NaturaNaturaNaturaNatura andandandand USPUSPUSPUSP
Thank you for your Thank you for your Thank you for your Thank you for your 
attentionattentionattentionattention
QuestionsQuestionsQuestionsQuestions? ? ? ? 
ObrigadaObrigadaObrigadaObrigada
vanessarocha@natura.netvanessarocha@natura.netvanessarocha@natura.netvanessarocha@natura.net