Forensics & Toxicology 2019

Prediction of human response to chemical exposures is the primary challenge of pharmaceutical and environmental toxicology research. The complexity of human responses to xenobiotic exposures presents significant challenges to modeling and multi-faceted characterization of toxicological and pharmacological dynamics.  At the National Toxicology Program, we are developing novel approaches to estimate human hepatic response to xenobiotic exposures through development and application of physiologically-relevant in vitro liver models.  In particular, we have focused on modeling functionally-relevant drug metabolism competence and metabolic activation of xenobiotics associated with liver injury including environmental compounds (benzo(a)pyrene & aflatoxin) and pharmaceuticals (e.g., cyclophosphamide, troglitazone, & trovafloxacin). Pairing these differentiated cell culture models with high dimensional assay platforms (e.g., high throughput transcriptomics, cell health) has enabled development and qualification of new approach methods that leverage the biological relevance of 3D culture models with the resolving power of concentration-response modeling.  This includes quantitative estimation of liver injury potential with unknown chemical exposures.  The results have revealed the power of resolution achieve through concentration-response modeling to characterize and de-convolute the complexities of biological response to xenobiotic exposures towards translational application and toxicological interpretation. 

Learning Objectives: 

1. Understand the impact of 3D cell culture on liver metabolism modeling in vitro
2. Become familiar with data-driven estimations of liver injury potential in response to xenobiotic exposures using high throughput transcriptomics
 

The incidence of conditions such as diabetes, obesity, asthma, and cancer have increased substantially in the past 30 years. The human genome has not changed in that period of time, so the environment is the likely cause of much of this increase. Our “environment” is very broad and includes industrial and agricultural chemicals, physical agents such as heat and radiation, food and nutrients, prescription drugs, by-products of combustion and industrial processes (e.g., dioxin), lifestyle choices (including substance abuse), social and economic factors, infectious agents, and the microbiome (i.e., gut flora). We cannot understand the full etiology of disease without a more complete understanding of the role of the environment in disease. In the past, basic toxicology focused on the simple dichotomy of toxic versus nontoxic, which implies that all substances can be harmful at high doses while at some lower dose, no harm is done. However, we now know that some environmental chemicals can create physiologically relevant effects at low doses, and these effects can have a substantial impact on our health. Every individual responds differently to the myriad of environmental stressors to which we are exposed.  Developing a robust understanding of the sources and magnitude of that variability is essential to inform risk-based decision making within individual, community and regulatory contexts. The list of chemicals that can cause altered developmental programming as well as the list of diseases shown to be affected by environmental exposures continues to expand.  The National Institute of Environmental Health Sciences (NIEHS) is one of the 27 research institutes and centers that comprise the National Institutes of Health (NIH), and its mission is to discover how the environment affects people in order to promote healthier lives. NIEHS continues to support research focused on mechanisms by which environmental exposures lead to increased risk of disease, the mechanisms behind the long latency and multigenerational effects, as well as the development of biomarkers of exposure and disease susceptibility which can be used to aid in disease prevention and intervention.  

Learning Objectives: 

1. Understand the wide range of environmental chemical exposures and how they may impact our health,   
2. Recognize the role of individual varibility in health related responses, and
3. Identify opportunities to modify our environment to reduce potentially harmful exposures.  
 

Contemporary law enforcement has greatly expanded its ability to solve crimes by the adoption of advanced forensic techniques, electronic monitoring and new approaches in crime scene procedures. Today, crimes often can be solved by the combinations detailed examination of the crime scene and recordings, analysis of forensic evidence, and reconstruction of the crime scene.  Knowledge of forensic evidence is not only crucial in criminal investigations and prosecutions, but also vital in civil litigations, major man-made and natural disasters, and the investigation of global crimes.  In addition to traditional detective work, the new concept of the successful solving of cases is based on multidiscipline approaches in forensic investigation.  A multidiscipline forensic investigation system combines the following six elements; 

1. Crime Scene Analysis 
2. Advanced Forensic Technology 
3. Victim, Suspect and Witness Informatics  
4. Public Information Gathering 
5. Big Data and recording Mining 
6. Intelligence Analytics 

Forensic Science is an application of variety of scientific technologies into the matter of law. Therefore, forensic science, itself is also a multidiscipline field. In addition to traditional medical, chemical, biological, immunological, toxicological, instrumental, physical and microscopical methods are used for the analysis of physical evidence. The advanced investigative skills, such as; GPS positioning, Cell phone tracking, Social network, E-evidence, Video image analysis, Big Date Analytics, Artificial intelligence, Theory formation, NG DNA typing, Trace Evidence Analysis, Pattern Evidence enhancement and Crime Reconstruction are also used in modern forensic investigation. Famous cases will be utilized to illustrate the importance of application of new concepts in criminal Investigation.

Learning Objectives: 

1. Explain the New Concept of Forensic Investigation
2. The interaction between Crime Scene and Forensic Evidence
3. The Different Types of Forensic Evidence
4. Understand the Multidisciplinary Nature of Forensic Science
5. Discuss the contemporary Techniques used in the Forensic Field

DNA profiling tools to teach undergraduate students about forensics generally utilize the PV92 Alu and D1S80 VNTR markers, but are both limited in scope. In contrast, advanced profiling systems are costly and not practical for undergraduate laboratory courses. Therefore, I have designed a DNA profiling system for use in mid- to upper-level UG laboratory courses. Three dimorphic Alu-based PCR tetraplexes were developed that are simple to use, yet yield complex DNA profiles with 531,441 possible outcomes. This profiling system allows students to study forensics, paternity, human populations, and may have potential use in determining ancestry. A corresponding web site was developed to incorporate and analyze the generated data. In addition, I have designed a second project based on the concerted evolution of mammalian L1 elements yielding forensic and evolutionary data. This project involves student generated intra-L1 PCR DNA libraries, which are biased for “younger” elements, and utilizes a toolbox of standard molecular genetic techniques and bioinformatic tools. Students query sequences from individual clones via GenBank to identify the organism (or related organism) of the DNA source. Students can also generate a molecular phylogeny of sequences to contrast to known phylogenetic relationships of mammals, and will be the basis of a long-term project to produce a mammalian tree-of-life. These projects, suitable for genetics, molecular genetics, or genomics laboratories represent the initial phase for developing large-scale consortium-based projects.

Learning Objectives: 

1. Defining retrotransposons and their contributions to the dynamics of mammalian genomes
2. The use of retrotransposons as tools in analyses of forensics, ancestry, population genetics, and evolution

Standards setting is an important process for improving forensic science. Guidelines, minimum practice and best standards all have their place in forensic toxicology. This lecture will focus on differences between minimum and best practices for toxicology in a forensic setting. Case studies will be used to illustrate where things can “go wrong” when minimum practices are not followed and also when best practices are followed.

Learning Objectives:

1. Attendees of this workshop will be able to compare and contrast the various levels of practice (best and minimum) in forensic toxicology and cite current gaps and opportunities for improvement in the area.