Validation of the 3D reconstructed human skin micronucleus (RSMN) assay: an animal-free alternative for following-up positive results from standard in vitro genotoxicity assays.

In vitro test batteries have become the standard approach to determine the genotoxic potential of substances of interest across industry sectors. While useful for hazard identification, standard in vitro genotoxicity assays in 2D cell cultures have limited capability to predict in vivo outcomes and may trigger unnecessary follow-up animal studies or the loss of promising substances where animal tests are prohibited or not desired. To address this problem, a team of regulatory, academia and industry scientists was established to develop and validate 3D in vitro human skin-based genotoxicity assays for use in testing substances with primarily topical exposure. Validation of the reconstructed human skin micronucleus (RSMN) assay in MatTek Epi-200™ skin models involved testing 43 coded chemicals selected by independent experts, in four US/European laboratories. The results were analysed by an independent statistician according to predefined criteria. The RSMN assay showed a reproducibly low background micronucleus frequency and exhibited sufficient capacity to metabolise pro-mutagens. The overall RSMN accuracy when compared to in vivo genotoxicity outcomes was 80%, with a sensitivity of 75% and a specificity of 84%, and the between- and within-laboratory reproducibility was 77 and 84%, respectively. A protocol involving a 72-h exposure showed increased sensitivity in detecting true positive chemicals compared to a 48-h exposure. An analysis of a test strategy using the RSMN assay as a follow-up test for substances positive in standard in vitro clastogenicity/aneugenicity assays and a reconstructed skin Comet assay for substances with positive results in standard gene mutation assays results in a sensitivity of 89%. Based on these results, the RSMN assay is considered sufficiently validated to establish it as a 'tier 2' assay for dermally exposed compounds and was recently accepted into the OECD's test guideline development program.

Infectious Diseases Physicians: Improving and Protecting the Public's Health: Why Equitable Compensation Is Critical.

Infectious diseases (ID) physicians play a crucial role in public health in a variety of settings. Unfortunately, much of this work is undercompensated despite the proven efficacy of public health interventions such as hospital acquired infection prevention, antimicrobial stewardship, disease surveillance, and outbreak response. The lack of compensation makes it difficult to attract the best and the brightest to the field of ID, threatening the future of the ID workforce. Here, we examine compensation data for ID physicians compared to their value in population and public health settings and suggest policy recommendations to address the pay disparities that exist between cognitive and procedural specialties that prevent more medical students and residents from entering the field. All ID physicians should take an active role in promoting the value of the subspecialty to policymakers and influencers as well as trainees.

Nonnucleoside Reverse-transcriptase Inhibitor- vs Ritonavir-boosted Protease Inhibitor-based Regimens for Initial Treatment of HIV Infection: A Systematic Review and Metaanalysis of Randomized Trials.

BACKGROUND: Previous studies suggest that nonnucleoside reverse-transcriptase inhibitors (NNRTIs) cause faster virologic suppression, while ritonavir-boosted protease inhibitors (PI/r) recover more CD4 cells. However, individual trials have not been powered to compare clinical outcomes. METHODS: We searched databases to identify randomized trials that compared NNRTI- vs PI/r-based initial therapy. A metaanalysis calculated risk ratios (RRs) or mean differences (MDs), as appropriate. Primary outcome was death or progression to AIDS. Secondary outcomes were death, progression to AIDS, and treatment discontinuation. We calculated RR of virologic suppression and MD for an increase in CD4 cells at week 48. RESULTS: We included 29 trials with 9047 participants. Death or progression to AIDS occurred in 226 participants in the NNRTI arm and in 221 in the PI/r arm (RR, 1.03; 95% confidence interval, .87-1.22; 12 trials; n = 3825), death in 205 participants in the NNRTI arm vs 198 in the PI/r arm (1.04; 0.86-1.25; 22 trials; n = 8311), and progression to AIDS in 140 participants in the NNRTI arm vs 144 in the PI/r arm (1.00; 0.80-1.25; 13 trials; n = 4740). Overall treatment discontinuation (1.12; 0.93-1.35; 24 trials; n = 8249) and from toxicity (1.21; 0.87-1.68; 21 trials; n = 6195) were comparable, but discontinuation due to virologic failure was more common with NNRTI (1.58; 0.91-2.74; 17 trials; n = 5371). At week 48, there was no difference between NNRTI and PI/r in virologic suppression (RR, 1.03; 0.98-1.09) or CD4(+) recovery (MD, -4.7 cells; -14.2 to 4.8). CONCLUSIONS: We found no difference in clinical and viro-immunologic outcomes between NNRTI- and PI/r-based therapy.

Implementation of New Test Methods into Practical Testing.

New toxicology test methods, especially those using in vitro methods, are continually being developed. Some are used by industry for screening purposes; others are eventually validated for regulatory use. However, for a new test method to be firmly adopted by industry it must be readily available, generally through an in-house industry laboratory, an academic laboratory, or a contract research organization. Regardless of the type of laboratory which intends to implement the test method, certain steps must be taken to ascertain that the method that is put into place is reproducible and performs identically to the test method that was published or has undergone validation. This involves developing protocols and standard operating procedures, training staff, developing historic positive and negative control data, establishing acceptable performance with proficiency chemicals, and addressing all the safety concerns that may accompany the assay. From experience within a contract research laboratory, we provide guidance on how to most efficiently accomplish these tasks.

Local tolerance testing under REACH: Accepted non-animal methods are not on equal footing with animal tests.

In general, no single non-animal method can cover the complexity of any given animal test. Therefore, fixed sets of in vitro (and in chemico) methods have been combined into testing strategies for skin and eye irritation and skin sensitisation testing, with pre-defined prediction models for substance classification. Many of these methods have been adopted as OECD test guidelines. Various testing strategies have been successfully validated in extensive in-house and inter-laboratory studies, but they have not yet received formal acceptance for substance classification. Therefore, under the European REACH Regulation, data from testing strategies can, in general, only be used in so-called weight-of-evidence approaches. While animal testing data generated under the specific REACH information requirements are per se sufficient, the sufficiency of weight-of-evidence approaches can be questioned under the REACH system, and further animal testing can be required. This constitutes an imbalance between the regulatory acceptance of data from approved non-animal methods and animal tests that is not justified on scientific grounds. To ensure that testing strategies for local tolerance testing truly serve to replace animal testing for the REACH registration 2018 deadline (when the majority of existing chemicals have to be registered), clarity on their regulatory acceptance as complete replacements is urgently required.

Impact of Climate Change on Cellulitis: A Literature Review.

Climate change is a phenomenon that has had, and will continue to have, wide-ranging effects on the world in both the near and distant future. With regards to human health, research has demonstrated the impact of climate change on heat-related illness, mental health, and vector-borne infectious diseases. Through a review of the literature, this paper aims to elucidate both current and future consequences of climate change on cellulitis, a type of skin infection that is associated with significant morbidity, mortality, and cost. Factors such as elevated temperature, pollution, rising sea levels, and the increased frequency of natural disasters pose an alarming risk for the increased proliferation of infections such as cellulitis. Lastly, in light of these trends, this paper will address potential strategies individuals can implement to reduce the effects of climate change on cellulitis.

Metabolism and disposition of vilanterol, a long-acting ß(2)-adrenoceptor agonist for inhalation use in humans.

The metabolism and disposition of vilanterol, a novel long-acting ß(2)-adrenoceptor agonist (LABA) for inhalation use, was investigated after oral administration in humans. Single oral administrations of up to 500 µg of vilanterol were shown to be safe and well tolerated in two clinical studies in healthy men. In a human radiolabel study, six healthy men received a single oral dose of 200 µg of [(14)C]vilanterol (74 kBq). Plasma, urine, and feces were collected up to 168 hours after the dose and were analyzed for vilanterol, metabolites, and radioactivity. At least 50% of the radioactive dose was orally absorbed. The primary route of excretion of drug-related material was via O-dealkylation to metabolites, which were mainly excreted in urine. Vilanterol represented a very small percentage (<0.5%) of the total drug-related material in plasma, indicative of extensive first-pass metabolism. Circulating metabolites resulted mainly from O-dealkylation and exhibited negligible pharmacologic activity. The therapeutic dose level for vilanterol is 25 µg by the inhalation route. At this low-dose level, the likelihood of pharmacologically inactive metabolites causing unexpected toxicity is negligible. In addition to providing an assessment of the disposition of vilanterol in human, this work highlights a number of complexities associated with determining human absorption, distribution, metabolism, and excretion (ADME) for inhaled molecules--mainly related to the low chemical doses and complications associated with the inhalation route of administration.

Efficacy and safety of crofelemer for noninfectious diarrhea in HIV-seropositive individuals (ADVENT trial): a randomized, double-blind, placebo-controlled, two-stage study.

BACKGROUND: HIV-associated diarrhea remains a significant concern with limited treatment options. OBJECTIVE: To determine the optimal dose, efficacy, and safety of crofelemer for noninfectious diarrhea. METHODS: This randomized, double-blind, phase 3 trial used a 2-stage design. Both stages included 2-week screening, 4-week placebo-controlled treatment, and 20-week placebo-free (open-label) extension phases. In stage I, 196 HIV-seropositive patients with chronic diarrhea were randomized to crofelemer 125 mg, 250 mg, or 500 mg or placebo twice daily. Using a prospective analysis, the 125-mg twice-daily dose was selected for stage II. In stage II, 180 new patients were randomized to crofelemer 125 mg twice daily or placebo for 4 weeks. Primary efficacy analysis was the percentage of patients (stages I/II combined) who achieved clinical response (defined as ≤2 watery stools/week during ≥2 of 4 weeks). During the placebo-free extension phase, response (≤2 watery stools) was assessed weekly. RESULTS: Significantly more patients receiving crofelemer 125 mg achieved clinical response versus placebo (17.6% vs 8.0%; one-sided, P = .01). Crofelemer 125 mg resulted in a greater change from baseline in number of daily watery bowel movements (P = .04) and daily stool consistency score (P = .02) versus placebo. During the placebo-free extension phase, percentages of weekly responders ranged from 40% to 56% at weeks 11 to 24. Crofelemer was minimally absorbed, well tolerated, did not negatively impact clinical immune parameters, and had a safety profile comparable to placebo. CONCLUSIONS: In HIV-seropositive patients taking stable antiretroviral therapy, crofelemer provided significant improvement in diarrhea with a favorable safety profile.

Evaluation of chemicals requiring metabolic activation in the EpiDerm™ 3D human reconstructed skin micronucleus (RSMN) assay.

The in vitro human reconstructed skin micronucleus (RSMN) assay in EpiDerm™ is a promising new assay for evaluating genotoxicity of dermally applied chemicals. A global pre-validation project sponsored by the European Cosmetics Association (Cosmetics Europe - formerly known as COLIPA), and the European Center for Validation of Alternative Methods (ECVAM), is underway. Results to date demonstrate international inter-laboratory and inter-experimental reproducibility of the assay for chemicals that do not require metabolism [Aardema et al., Mutat. Res. 701 (2010) 123-131]. We have expanded these studies to investigate chemicals that do require metabolic activation: 4-nitroquinoline-N-oxide (4NQO), cyclophosphamide (CP), dimethylbenzanthracene (DMBA), dimethylnitrosamine (DMN), dibenzanthracene (DBA) and benzo(a)pyrene (BaP). In this study, the standard protocol of two applications over 48h was compared with an extended protocol involving three applications over 72h. Extending the treatment period to 72h changed the result significantly only for 4NQO, which was negative in the standard 48h dosing regimen, but positive with the 72h treatment. DMBA and CP were positive in the standard 48h assay (CP induced a more reproducible response with the 72h treatment) and BaP gave mixed results; DBA and DMN were negative in both the 48h and the 72h dosing regimens. While further work with chemicals that require metabolism is needed, it appears that the RMSN assay detects some chemicals that require metabolic activation (4 out of 6 chemicals were positive in one or both protocols). At this point in time, for general testing, the use of a longer treatment period in situations where the standard 48h treatment is negative or questionable is recommended.

Pregnant women's use of information and communications technologies to access pregnancy-related health information in South Australia.

This paper examines how pregnant women living in South Australia use information and communication technologies (ICTs), principally Internet and mobile phones, to access pregnancy-related information. It draws on 35 semistructured interviews conducted as part of the 'Health-e Baby' project, a qualitative study designed to assess the information needs and ICT preferences of pregnant women cared for at a South Australian metropolitan teaching hospital. Our research shows that although ICTs offer exciting possibilities for health promotion and the potential for new forms of communication, networking and connection, we cannot assume the effectiveness of communicating through such channels, despite near universal levels of ICT access. In turn, this highlights that if e-mediated health promotion is to be effective, health promoters and practitioners need to better understand ICT access, usage and content preferences of their clients.

The AIMS approach: regulating receptivity in patient-provider vaccine conversations.

The World Health Organization named vaccine hesitancy a leading global health threat of modern time. Addressing this public health issue requires a multi-front strategy, one such strategic effort is training health care professionals to respond to reluctant patients/caregivers or those who refuse vaccines. AIMS (Announce, Inquire, Mirror, and Secure) is designed to help HCPs engaged in more productive conversations with patients/caregivers to secure trust, a key behavior leading to higher vaccination rates.

Etiology and pharmacologic management of noninfectious diarrhea in HIV-infected individuals in the highly active antiretroviral therapy era.

Diarrhea remains a common problem for patients with human immunodeficiency virus (HIV) infection despite highly active antiretroviral therapies (HAART) and can negatively affect patient quality of life and lead to discontinuation or switching of HAART regimens. In the era of HAART, diarrhea from opportunistic infections is uncommon, and HIV-associated diarrhea often has noninfectious causes, including HAART-related adverse events and HIV enteropathy. Diarrhea associated with HAART is typically caused by protease inhibitors (eg, ritonavir), which may damage the intestinal epithelial barrier (leaky-flux diarrhea) and/or alter chloride ion secretion (secretory diarrhea). HIV enteropathy may result from direct effects of HIV on gastrointestinal tract cells and on the gastrointestinal immune system and gut-associated lymphoid tissue, which may be active sites of HIV infection and ongoing inflammation and mucosal damage. New therapies targeting the pathogenic mechanisms of noninfectious diarrheas are needed.

Asymptomatic SARS-CoV-2 Infection Is Common Among ART-Treated People With HIV.

BACKGROUND: Limited data are available regarding asymptomatic COVID-19 among people with HIV (PWH). Data on a representative subset of PWH enrolled in Randomized Trial to Prevent Vascular Events in HIV, a global clinical trial, are presented here. METHODS: Randomized Trial to Prevent Vascular Events in HIV is an atherosclerotic cardiovascular disease prevention trial among 7770 PWH on antiretroviral therapy. Beginning April 2020, targeted data on coronavirus disease 2019 (COVID-19) diagnosis and symptoms were collected during routine trial visits. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was defined as either COVID-19 clinical diagnosis or presence of SARS-CoV-2 Immunoglobulin G (IgG) or Immunoglobulin A (IgA) receptor binding domain protein (antispike) antibodies in the absence of prior COVID-19 vaccine. RESULTS: The group (N = 2464) had a median age 53 years, 35% female sex, 47% Black or African American race, median CD4 count 649 c/mm 3 , and 97% with HIV VL <400 cp/m. SARS-CoV-2 infection occurred in 318 persons (13%): 58 with clinical diagnosis and 260 with detectable antibodies. Of these PWH, 304 completed symptom questionnaires: 121 (40%) reported symptoms, but 183 (60%) were asymptomatic. PWH with asymptomatic SARS-CoV-2 infection were more likely to be from low-income or middle-income regions, of Black or African American race, older in age, and with higher atherosclerotic cardiovascular disease risk score. Symptomatic COVID was more common with obesity, metabolic syndrome, and low HDL levels. CD4 counts and HIV viral suppression rates were similar among PWH with symptomatic vs. asymptomatic COVID. CONCLUSIONS: Asymptomatic SARS-CoV-2 infection is common among antiretroviral therapy-treated PWH globally. We determined that 60% of infections in PWH were asymptomatic. HIV clinicians must remain vigilant about COVID-19 testing among PWH to identify asymptomatic cases.

Ethnicity and gender differences in lipodystrophy of HIV-positive individuals taking antiretroviral therapy in Ontario, Canada.

PURPOSE: This study assessed ethnicity and gender differences in prevalence, type, and severity of antiretroviral-associated lipodystrophy in HIV-positive individuals in Ontario. METHODS: This was a cross-sectional analysis of the Ontario Cohort Study (OCS), a prospective study of HIV-positive patients in Ontario. Lipodystrophy was defined as at least 1 major or 2 minor self-reported changes of peripheral lipoatrophy and/or central lipohypertrophy. Prevalence, type, and severity were compared by ethnicity (Black, White, or Other) and gender. Univariate and multivariate logistic regression analyses identified predictors of lipodystrophy. RESULTS: Data were available for 778 participants (659 men, 119 women). There were 517 Whites, 121 Blacks, and 140 patients of Other ethnicities. In univariate analyses, Whites reported more peripheral lipoatrophy (P = .004) and abdominal lipohypertrophy (P = .04); these ethnic differences were observed in males (P = .05 and P = .03, respectively) but not females. Males reported more peripheral lipoatrophy (P = .01), whereas females had more central lipohypertrophy (P < .0001) and mixed fat redistribution (P < .0001). Multivariable regression analyses revealed Black women to be most vulnerable to lipodystrophy (P = .02), particularly lipohypertrophy (P < .0001). CONCLUSIONS: Ethnicity and gender are important factors influencing lipodystrophy. Combining lipoatrophy and lipohypertrophy into a single entity is not appropriate. Black women were most vulnerable to lipohypertrophy, which has important implications for antiretroviral therapy roll-out in Africa.

Expression of TREM-1 is inhibited by PGD2 and PGJ2 in macrophages.

TREM-1 is a superimmunoglobulin receptor present on neutrophils and monocytes, which plays an important role in the amplification of inflammation. The natural ligands for TREM-1 have not been identified; however, Toll-like receptor ligands are known to induce the expression of TREM-1. Blockade of TREM-1 has shown to improve survival in animal models of sepsis. In the present studies, we investigated the role of lipid mediators in the expression of TREM-1. In a macrophage cell line, we show that the expression of TREM-1 in response to LPS and bacteria Pseudomonas aeruginosa is inhibited by PGD(2) and cyclopentanone prostaglandins PGJ(2) and 15-dPGJ(2). The inhibition of TREM-1 by these prostaglandins is independent of the PGD(2) receptors and PPARγ but occurs by activation of Nrf2 and inhibition of NF-κB. Our data suggest a novel mechanism by which these prostaglandins exhibit anti-inflammatory effects and a new therapeutic approach to inhibition of TREM-1.

Adapting Education at the Medical College of Georgia at Augusta University in Response to the COVID-19 Pandemic: the Pandemic Medicine Elective.

The Medical College of Georgia (MCG) responded to the COVID-19 pandemic's challenges to medical education with a novel, comprehensive curriculum. The Pandemic Medicine Elective was an effective solution with a safe, virtual alternative to traditional clinical experiences. As the elective evolved to include pre-clinical students and service initiatives across Georgia, students and faculty navigated online platforms to execute critical community-based projects. This curricular development utilized an interdisciplinary approach by faculty across each of MCG's regional campuses. We describe the curriculum of the electives, the student initiatives, and lessons learned while quickly adapting curriculum during the COVID-19 pandemic.

International prevalidation studies of the EpiDerm 3D human reconstructed skin micronucleus (RSMN) assay: transferability and reproducibility.

Recently, a novel in vitro reconstructed skin micronucleus (RSMN) assay incorporating the EpiDerm 3D human skin model (Curren et al., Mutat. Res. 607 (2006) 192-204; Mun et al., Mutat. Res. 673 (2009) 92-99) has been shown to produce comparable data when utilized in three different laboratories in the United States (Hu et al., Mutat. Res. 673 (2009) 100-108). As part of a project sponsored by the European cosmetics companies trade association (COLIPA), with a contribution from the European Center for the Validation of Alternative Methods (ECVAM), international prevalidation studies of the RSMN assay have been initiated. The assay was transferred and optimized in two laboratories in Europe, where dose-dependent, reproducibly positive results for mitomycin C and vinblastine sulfate were obtained. Further intra- and inter-laboratory reproducibility of the RSMN assay was established by testing three coded chemicals, N-ethyl-N-nitrosourea, cyclohexanone, and mitomycin C. All chemicals were correctly identified by all laboratories as either positive or negative. These results support the international inter-laboratory and inter-experimental reproducibility of the assay and reinforce the conclusion that the RSMN assay in the EpiDerm 3D human skin model is a valuable in vitro method for assessment of genotoxicity of dermally applied chemicals.

Widely Disseminated Cryptococcosis Manifesting in a Previously Undiagnosed Human Immunodeficiency Virus (HIV)-Positive 18-Year-Old.

BACKGROUND After initial infection with HIV, loss of CD4+ T cells progresses along a predictable timeline. The clinical latency stage lasts an average of 10 years, until the CD4+ T cell count falls below 200 cells/uL or the patient develops an AIDS-defining opportunistic infection/cancer. This report describes an unusual opportunistic infection in a young patient with no prior clinical evidence of HIV infection. CASE REPORT An 18-year-old man presented with fever, abdominal pain, and dyspnea for the previous 2 weeks and was symptomatically treated for gastroenteritis. He presented 2 weeks later with extreme fatigue, and a CT scan revealed diffuse lymphadenopathy. He was transferred to a regional hospital, but upon arrival and prior to detailed investigative work-up, he developed cardiac arrest. Despite maximal resuscitative efforts, he died approximately 8 h after admission. At autopsy, diffuse lymphadenopathy, splenomegaly, and pulmonary congestion were noted. Disseminated cryptococcal infection involving almost every organ system was identified at autopsy. A postmortem HIV-1 antibody test was positive. The cause of death was severe immunodeficiency as a result of advanced HIV infection resulting in disseminated cryptococcal infection, with cerebral edema, herniation, and respiratory failure. CONCLUSIONS This patient's non-specific symptoms in conjunction with his rapid decline made arriving at a correct diagnosis challenging. Only during autopsy was the disseminated fungal infection discovered, leading to suspicion of HIV infection. HIV autopsies are not uncommon, but the clinical history is usually known beforehand. This case report highlights the importance of considering HIV-related conditions in patients presenting with this array of symptoms, as well as to alert healthcare providers and staff to the need for increased biosafety precautions.

Intralaboratory and interlaboratory evaluation of the EpiDerm 3D human reconstructed skin micronucleus (RSMN) assay.

A novel in vitro human reconstructed skin micronucleus (RSMN) assay has been developed using the EpiDerm 3D human skin model [R. D. Curren, G. C. Mun, D. P. Gibson, and M. J. Aardema, Development of a method for assessing micronucleus induction in a 3D human skin model EpiDerm, Mutat. Res. 607 (2006) 192-204]. The RSMN assay has potential use in genotoxicity assessments as a replacement for in vivo genotoxicity assays that will be banned starting in 2009 according to the EU 7th Amendment to the Cosmetics Directive. Utilizing EpiDerm tissues reconstructed with cells from four different donors, intralaboratory and interlaboratory reproducibility of the RSMN assay were examined. Seven chemicals were evaluated in three laboratories using a standard protocol. Each chemical was evaluated in at least two laboratories and in EpiDerm tissues from at least two different donors. Three model genotoxins, mitomycin C (MMC), vinblastine sulfate (VB) and methyl methanesulfonate (MMS) induced significant, dose-related increases in cytotoxicity and MN induction in EpiDerm tissues. Conversely, four dermal non-carcinogens, 4-nitrophenol (4-NP), trichloroethylene (TCE), 2-ethyl-1,3-hexanediol (EHD), and 1,2-epoxydodecane (EDD) were negative in the RSMN assay. Results between tissues reconstructed from different donors were comparable. These results indicate the RSMN assay using the EpiDerm 3D human skin model is a promising new in vitro genotoxicity assay that allows evaluation of chromosome damage following "in vivo-like" dermal exposures.

Further development of the EpiDerm 3D reconstructed human skin micronucleus (RSMN) assay.

The upcoming ban on testing of cosmetics in animals by the European Union's 7th Amendment to the Cosmetics Directive will require genotoxicity safety assessments of cosmetics ingredients and final formulations to be based primarily on in vitro genotoxicity tests. The current in vitro test battery produces an unacceptably high rate of false positives, and used by itself would effectively prevent the use and development of many ingredients that are actually safe for human use. To address the need for an in vitro test that is more predictive of genotoxicity in vivo, we have developed an in vitro micronucleus assay using a three-dimensional human reconstructed skin model (EpiDerm) that more closely mimics the normal dermal exposure route of chemicals. We have refined this model and assessed its ability to predict genotoxicity of a battery of chemicals that have been previously classified as genotoxins or non-genotoxins based on in vivo rodent skin tests. Our reconstructed skin micronucleus assay correctly identified 7 genotoxins and 5 non-genotoxins, demonstrating its potential to have a higher predictive value than currently available in vitro genotoxicity tests, and its utility as part of a comprehensive in vitro genotoxicity testing strategy.