Breaking News
September 21, 2018 - 30 Million Americans Now Have Diabetes
September 21, 2018 - Thousands of breast cancer gene variants engineered and analyzed
September 21, 2018 - The current fellowship interview process is cumbersome — Stanford researchers have a better idea
September 21, 2018 - Progenitor cells for human bone and cartilage have been identified
September 21, 2018 - Study reveals new therapeutic target for pediatric tumor-associated intractable epilepsy
September 21, 2018 - SLU’s College professor receives NIH grant to develop I-TEST project
September 21, 2018 - DermTech completes enrollment in clinical study to assess DNA damage and reversal
September 21, 2018 - Grieving patients treated with talk therapy have lower risk of suicide and psychiatric illness
September 21, 2018 - NIH and FDA call for eliminating involvement of RAC in human gene therapy experiments
September 21, 2018 - New system uses algorithm to convert 2D videos into 3D printed ‘motion sculptures’
September 21, 2018 - Sea squirt model reveals key molecules in dopaminergic neuron differentiation
September 21, 2018 - Effective management of neonatal abstinence syndrome requires coordinated ‘cascade of care’
September 21, 2018 - Refugees seek care for wounds of war
September 21, 2018 - Under the sea, in an octopus’ garden on ecstacy
September 21, 2018 - Eating foods with low nutritional quality ratings linked to cancer risk in large European cohort
September 21, 2018 - Giving kids honest information about water consumption may help them make healthy choices
September 21, 2018 - Horwitz Prize Awarded for Work on Hormones
September 21, 2018 - CHMP issues positive opinion supporting use of Trelegy Ellipta in broader group of COPD patients
September 21, 2018 - Scientists discover new molecules that work together to remove unwanted DNA
September 21, 2018 - Dr. Fenella France to deliver 2019 Plenary Lecture
September 21, 2018 - New research finds that MHC-II molecules have more influence on tumors than MHC-I
September 21, 2018 - Researchers study effects of cardiac cycle in simple learning task
September 21, 2018 - FDA takes new steps to address opioid crisis by approving Opioid Analgesic Risk Evaluation and Mitigation Strategy
September 21, 2018 - Positive Barhemsys Phase 3 Treatment Data Published in Anesthesia & Analgesia
September 21, 2018 - Celiac Disease Screening: MedlinePlus Lab Test Information
September 21, 2018 - Autism linked to egg cells’ difficulty creating large proteins
September 21, 2018 - Tweaking nuclear pores could provide new avenue to battle against cancer
September 21, 2018 - Experts warn health care providers to slow down in allowing smart pill in patient care settings
September 21, 2018 - MoreGrasp reports breakthrough development of grasp neuroprosthetics activated by thought control
September 21, 2018 - Study reveals new way to target HER2-negative metastatic breast cancer
September 21, 2018 - CHMP grants positive opinion for VENCLYXTO plus rituximab for treating relapsed/refractory CLL
September 21, 2018 - Study offers solid link between visceral organs and brain’s reward, motivation system
September 21, 2018 - First U.S. patient treated with innovative gene therapy at Bascom Palmer Eye Institute
September 21, 2018 - Choroidal Detachment – The American Society of Retina Specialists
September 21, 2018 - New clinical trial evaluates aesthetic results of conservative surgery in breast cancer
September 21, 2018 - Discovery of a key protein involved in the development of autism
September 21, 2018 - Air pollution appears to be linked to increased risk of developing dementia
September 21, 2018 - Henry Ford Health System receives $600k grant to study genetic makeup of gliomas
September 21, 2018 - Arthritis common in individuals with varying degrees of depression, finds study
September 21, 2018 - Scientist intends to fight pathogenic bacteria with viruses
September 21, 2018 - New research suggests link between PFAS chemicals and hyperthyroidism in pet cats
September 21, 2018 - Multi-year study data shows impact of new soft contact lens to slow myopia progression in children
September 21, 2018 - Neuroscientists identify circuit for brain’s statistical inference about motion
September 21, 2018 - MILabs’ VECTor6 system wins Commercial Innovation Award at WMIC 2018
September 21, 2018 - Scientists find wild African monkeys infected with bacterium that causes syphilis, yaws in humans
September 21, 2018 - 2006 to 2015 Saw Increase in Severe Maternal Morbidity
September 21, 2018 - Similar changes in the brains of patients with ADHD and emotional instability
September 21, 2018 - Cobalt mining in DR Congo takes a high toll on both creuseurs and environment
September 21, 2018 - Eating fatty fish during pregnancy may boost unborn child’s brain development
September 21, 2018 - Study reveals promising new drug candidate to treat acute renal failure
September 21, 2018 - Neural signal that urges to eat overpowers the one that says to stop
September 21, 2018 - Scientists achieve breakthrough in accelerated diagnosis of multi-resistant hospital pathogens
September 21, 2018 - Researchers simulate how different breast tissues respond to heat from MRIs
September 21, 2018 - Despite red flags at surgery centers, overseers award gold seals
September 21, 2018 - Zapping Airway Nerves May Help COPD Patients Breathe
September 21, 2018 - Researchers find answers as to why some people are at risk of gout
September 21, 2018 - Stars of Stanford Medicine: Genetic counseling and compassion
September 21, 2018 - Researchers use reinforcement learning to train gliders to soar like birds
September 21, 2018 - New federally-funded research project could lead to treatments that extend human lifespan
September 21, 2018 - Health insurance ads have shifted over time due to health plans offered via ACA
September 21, 2018 - Use of transcranial electrical stimulation to bolster creativity has far-reaching implications
September 21, 2018 - Scientists find way to boost efficacy of powerful antimalarial drug with anti-cancer medicines
September 21, 2018 - Weighing the risks and benefits of drug tapering—two patients, two perspectives
September 21, 2018 - The “exposome” revealed: a barrage of bacteria, chemicals, microscopic animals and more
September 21, 2018 - Top three immune boosting recommendations to ward off freshers’ flu
September 21, 2018 - Young children’s oral microbiota could serve as early indicator for obesity
September 21, 2018 - Older individuals with multiple sclerosis report higher quality of life than younger counterparts
September 21, 2018 - LineaRx signs agreement with Takis/Evvivax to develop linear-DNA based anti-cancer vaccines
September 21, 2018 - AbbVie Presents Upadacitinib Longer-Term (32-Week) and Patient-Reported Outcomes Data from Phase 2b Atopic Dermatitis Study at 27th European Academy of Dermatology and Venereology (EADV) Congress
September 21, 2018 - Alzheimer’s drug may stop disease if used before symptoms develop
September 21, 2018 - Human skeletal stem cell can generate cartilage, bone
September 21, 2018 - UK and European research collaborations receive vote of confidence by three major cancer charities
September 21, 2018 - Microbiota in the intestines and cell stress cause colon cancer
September 20, 2018 - Arizona EMTs have 39% higher risk for suicide than general public
September 20, 2018 - Driving and older adults: MedlinePlus Medical Encyclopedia
September 20, 2018 - Brain region for stress control is enlarged in people with depression, finds study
September 20, 2018 - Researchers test autobiographical memory for early Alzheimer’s detection
September 20, 2018 - Organizations join forces to help teens with severe mental health challenges | News Center
September 20, 2018 - Neurons in the human brain can encode numerical information
September 20, 2018 - Potential drugs to treat neurodegenerative diseases garner $3 million grant
Study suggests database analysis better predicts toxicity of chemicals than animal testing

Study suggests database analysis better predicts toxicity of chemicals than animal testing

image_pdfDownload PDFimage_print

Advanced algorithms working from large chemical databases can predict a new chemical’s toxicity better than standard animal tests, suggests a study led by scientists at Johns Hopkins Bloomberg School of Public Health.

The researchers, in the study that appears in the journal Toxicological Sciences on July 11, mined a large database of known chemicals they developed to map the relationships between chemical structures and toxic properties. They then showed that one can use the map to automatically predict the toxic properties of any chemical compound–more accurately than a single animal test would do.

The most advanced toxicity-prediction tool the team developed was on average about 87 percent accurate in reproducing consensus animal-test-based results–across nine common tests, which account for 57 percent of the world’s animal toxicology testing. By contrast, the repetition of the same animal tests in the database were only about 81 percent accurate–in other words, any given test had only an 81 percent chance, on average, of obtaining the same result for toxicity when repeated.

“These results are a real eye-opener–they suggest that we can replace many animal tests with computer-based prediction and get more reliable results,” says principal investigator Thomas Hartung, MD, PhD, the Doerenkamp-Zbinden Chair and professor in the Department of Environmental Health and Engineering at the Bloomberg School.

The computer-based approach could also be applied to many more chemicals than animal testing, which could lead to wider safety assessments. Due to costs and ethical challenges only a small fraction of the roughly 100,000 chemicals in consumer products have been comprehensively tested.

Animals such as mice, rabbits, guinea pigs and dogs annually undergo millions of chemical toxicity tests in labs around the world. Although this animal testing is usually required by law to protect consumers, it is opposed on moral grounds by large segments of the public, and is also unpopular with product manufacturers because of the high costs and uncertainties about testing results.

“A new pesticide, for example, might require 30 separate animal tests, costing the sponsoring company about 20 million dollars,” says Hartung, who also directs the Center for Alternatives to Animal Testing, which is based in the Bloomberg School’s Department of Environmental Health and Engineering.

The most common alternative to animal testing is a process called read-across, in which researchers predict a new compound’s toxicity based on the known properties of few chemicals that have a similar structure. Read-across is much less expensive than animal testing, yet requires expert evaluation and somewhat subjective analysis for every compound of interest.

As a first step towards optimizing and automating the read-across process, Hartung and colleagues two years ago assembled the world’s largest machine-readable toxicological database. It contains information on the structures and properties of 10,000 chemical compounds, based in part on 800,000 separate toxicology tests.

“There is enormous redundancy in this database–we found that often the same chemical has been tested dozens of times in the same way, such as putting it into rabbits’ eyes to check if it’s irritating,” says Hartung. This waste of animals, however, gave the researchers information they needed to develop a benchmark for a better approach.

For their study, the team enlarged the database and used machine-learning algorithms, with computing muscle provided by Amazon’s cloud server system, to read the data and generate a “map” of known chemical structures and their associated toxic properties. They developed related software to determine precisely where any compound of interest belongs on the map, and whether–based on the properties of compounds “nearby”–it is likely to have toxic effects such as skin irritation or DNA damage.

“Our automated approach clearly outperformed the animal test, in a very solid assessment using data on thousands of different chemicals and tests,” Hartung says. “So it’s big news for toxicology.” Underwriter’s Laboratories (UL), a company that specializes in developing public safety standards and testing against them, co-sponsored this work and is making the read-across software tool commercially available.

The U.S. Food and Drug Administration and the Environmental Protection Agency have begun formal evaluations of the new method, to test if read-across can substitute for a significant proportion of the animal tests currently used to evaluate the safety of chemicals in foods, drugs and other consumer products. The researchers also are starting to use it to help some large corporations, including major technology companies, to determine if they have potentially toxic chemicals in their products.

“One day perhaps, chemists will use such tools to predict toxicity even before synthesizing a chemical so that they can focus on making only non-toxic compounds,” Hartung says.

Source:

https://www.jhsph.edu/news/news-releases/2018/database-analysis-more-reliable-than-animal-testing-for-toxic-chemicals.html

Tagged with:

About author

Related Articles