scholarly journals Validation, Optimization, and Application of the Zebrafish Developmental Toxicity Assay for Pharmaceuticals Under the ICH S5(R3) Guideline

2021 ◽  
Vol 9 ◽  
Author(s):  
Yi-Sheng Song ◽  
Ming-Zhu Dai ◽  
Chen-Xia Zhu ◽  
Yan-Feng Huang ◽  
Jing Liu ◽  
...  
Keyword(s):  
Developmental Toxicity ◽  
False Negative ◽  
Toxicity Testing ◽  
The United States ◽  
Toxicity Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Developmental Toxicity Testing ◽  
Classical Protocol

The zebrafish as an alternative animal model for developmental toxicity testing has been extensively investigated, but its assay protocol was not harmonized yet. This study has validated and optimized the zebrafish developmental toxicity assay previously reported by multiple inter-laboratory studies in the United States and Europe. In this study, using this classical protocol, of 31 ICH-positive compounds, 23 compounds (74.2%) were teratogenic in zebrafish, five had false-negative results, and three were neither teratogenic nor non-teratogenic according to the protocol standard; of 14 ICH-negative compounds, 12 compounds (85.7%) were non-teratogenic in zebrafish and two had false-positive results. After we added an additional TI value in the zebrafish treated with testing compounds at 2 dpf along with the original 5 dpf, proposed a new category as the uncategorized compounds for those TI values smaller than the cutoff both at 2 dpf and 5 dpf but inducing toxic phenotypes, refined the testing concentration ranges, and optimized the TI cut-off value from ≥ 10 to ≥ 3 for compounds with refined testing concentrations, this optimized zebrafish developmental assay reached 90.3% sensitivity (28/31 positive compounds were teratogenic in zebrafish) and 88.9% (40/45) overall predictability. Our results from this study strongly support the use of zebrafish as an alternative in vivo method for screening and assessing the teratogenicity of candidate drugs for regulatory acceptance.

Aspiration Revisited: Prospective Evaluation of a Physiologically Pressurized Model With Animal Correlation and Broader Applicability to Filler Complications

2021 ◽  
Author(s):  
Hyoung-Jin Moon ◽  
Won Lee ◽  
Ji-Soo Kim ◽  
Eun-Jung Yang ◽  
Hema Sundaram
Keyword(s):  
Normal Saline ◽  
False Negative ◽  
Vascular Complications ◽  
Filler Injection ◽  
Negative Results ◽  
Needle Position ◽  
False Negative Results ◽  
In Vivo Testing

Abstract Background Aspiration testing before filler injection is controversial. Some believe that aspiration can help prevent inadvertent intravascular injection, while others cite false-negative results and question its value given that the needle position always changes somewhat during injection procedures. Objectives To test the relation of false-negative results to the viscosity of the material within the needle lumen and determine whether a less viscous material within the needle lumen could decrease the incidence of false-negative results. Methods In vitro aspiration tests were performed using 30-G and 27-G needle gauges, two cross-linked hyaluronic acid fillers, normal saline bags pressurized at 140 and 10 mmHg to mimic human arterial and venous pressures, and three needle lumen conditions (normal saline, air, and filler). Testing was repeated three times under each study condition (72 tests in total). For in vivo correlation, aspiration tests were performed on femoral arteries and central auricular veins in three rabbits (4–5 aspirations per site, 48 tests in total). Results In vitro and in vivo testing using 30-G needles containing filler both showed false-negative results on aspiration testing. In vitro and in vivo testing using needles containing saline or air showed positive findings. Conclusions False-negative results from aspiration testing may be reduced by pre-filling the needle lumen with saline rather than a filler. The pressurized system may help overcome challenges of animal models with intravascular pressures significantly different from those of humans. The adaptability of this system to mimic various vessel pressures may facilitate physiologically relevant studies of vascular complications.

scholarly journals The 28 + 28 day design is an effective sampling time for analyzing mutant frequencies in rapidly proliferating tissues of MutaMouse animals

2021 ◽  
Vol 95 (3) ◽  
pp. 1103-1116
Author(s):  
Francesco Marchetti ◽  
Gu Zhou ◽  
Danielle LeBlanc ◽  
Paul A. White ◽  
Andrew Williams ◽  
...  
Keyword(s):  
Germ Cells ◽  
False Negative ◽  
Sampling Time ◽  
Male Germ Cells ◽  
Negative Results ◽  
False Negative Results ◽  
Detection Of Mutations ◽  
The Impact ◽  
Sampling Times

AbstractThe Organisation for Economic Co-Operation and Development Test Guideline 488 (TG 488) uses transgenic rodent models to generate in vivo mutagenesis data for regulatory submission. The recommended design in TG 488, 28 consecutive daily exposures with tissue sampling three days later (28 + 3d), is optimized for rapidly proliferating tissues such as bone marrow (BM). A sampling time of 28 days (28 + 28d) is considered more appropriate for slowly proliferating tissues (e.g., liver) and male germ cells. We evaluated the impact of the sampling time on mutant frequencies (MF) in the BM of MutaMouse males exposed for 28 days to benzo[a]pyrene (BaP), procarbazine (PRC), isopropyl methanesulfonate (iPMS), or triethylenemelamine (TEM) in dose–response studies. BM samples were collected + 3d, + 28d, + 42d or + 70d post exposure and MF quantified using the lacZ assay. All chemicals significantly increased MF with maximum fold increases at 28 + 3d of 162.9, 6.6, 4.7 and 2.8 for BaP, PRC, iPMS and TEM, respectively. MF were relatively stable over the time period investigated, although they were significantly increased only at 28 + 3d and 28 + 28d for TEM. Benchmark dose (BMD) modelling generated overlapping BMD confidence intervals among the four sampling times for each chemical. These results demonstrate that the sampling time does not affect the detection of mutations for strong mutagens. However, for mutagens that produce small increases in MF, sampling times greater than 28 days may produce false-negative results. Thus, the 28 + 28d protocol represents a unifying protocol for simultaneously assessing mutations in rapidly and slowly proliferating somatic tissues and male germ cells.

scholarly journals Immunoassay-Based Drug Tests Are Inadequately Sensitive for Medication Compliance Monitoring in Patients Treated for Chronic Pain

10.36076/se9 ◽  
2017 ◽  
Vol 2 (20;2) ◽  
pp. sE1-sE9 ◽  
Author(s):  
Stacy Melanson
Keyword(s):  
Mass Spectrometry ◽  
Chronic Pain ◽  
Pain Management ◽  
Drug Use ◽  
Illicit Drugs ◽  
False Negative ◽  
The United States ◽  
Enzyme Immunoassays ◽  
Negative Results ◽  
False Negative Results

Background: Enzyme immunoassays (EIA) have notable limitations for monitoring therapeutic compliance in pain management. Chromatography coupled with mass spectrometry provides definitive results and superior sensitivity and specificity over traditional EIA testing. Objective: To analyze and compare the sensitivity of EIA results together with known prescriptions to liquid chromatography-tandem mass spectrometry (LC-MS/MS) for monitoring drug use (and abuse) in patients treated for chronic pain. Study Design: A total of 530 urine samples from patients being treated for chronic pain were studied. Setting: Pain management clinic in the United States. Methods: The samples were tested for a profile of chronic pain medications and illicit drugs with commercially available EIA kits followed by analysis with Agilent LC-MS/MS system. Results: The EIAs exhibited poor sensitivity and high rates of false negative results in the pain management setting. For example, 21% of EIA for opiates show false negative results. Mass spectrometry methods were more sensitive, detected a broader range of drugs and metabolites, and could detect non-prescribed drug use and simulations in compliance. Limitations: Patients do not always accurately report drug use information, and some drugs do not have EIA methods available for comparative purposes. Conclusions: Mass spectrometry is a more robust and reliable method for detection of drugs used in the pain management setting. Due to the extent of undisclosed use and abuse of medications and illicit drugs, LC-MS/MS testing is necessary for adequate and accurate drug detection. In addition, LC-MS/MS methods are superior in terms of sensitivity and number of compounds that can be screened, making this a better method for use in pain management. Key words: Pain management, enzyme immunoassays, mass spectrometry, urine drug testing, prescription status, compliance

scholarly journals DMSO Concentrations up to 1% are Safe to be Used in the Zebrafish Embryo Developmental Toxicity Assay

2021 ◽  
Vol 3 ◽  
Author(s):  
Jente Hoyberghs ◽  
Chloé Bars ◽  
Miriam Ayuso ◽  
Chris Van Ginneken ◽  
Kenn Foubert ◽  
...  
Keyword(s):  
Zebrafish Embryo ◽  
Developmental Toxicity ◽  
Toxicity Testing ◽  
Negative Control ◽  
Zebrafish Embryos ◽  
Toxicity Assay ◽  
Dmso Concentration ◽  
Developmental Toxicity Testing ◽  
Positive Results

Dimethyl sulfoxide (DMSO) is a popular solvent for developmental toxicity testing of chemicals and pharmaceuticals in zebrafish embryos. In general, it is recommended to keep the final DMSO concentration as low as possible for zebrafish embryos, preferably not exceeding 100 μL/L (0.01%). However, higher concentrations of DMSO are often required to dissolve compounds in an aqueous medium. The aim of this study was to determine the highest concentration of DMSO that can be safely used in our standardized Zebrafish Embryo Developmental Toxicity Assay (ZEDTA). In the first part of this study, zebrafish embryos were exposed to different concentrations (0–2%) of DMSO. No increase in lethality or malformations was observed when using DMSO concentrations up to 1%. In a follow-up experiment, we assessed whether compounds that cause no developmental toxicity in the ZEDTA remain negative when dissolved in 1% DMSO, as false positive results due to physiological disturbances by DMSO should be avoided. To this end, zebrafish embryos were exposed to ascorbic acid and hydrochlorothiazide dissolved in 1% DMSO. Negative control groups were also included. No significant increase in malformations or lethality was observed in any of the groups. In conclusion, DMSO concentrations up to 1% can be safely used to dissolve compounds in the ZEDTA.

Developmental Toxicity Evaluation of Several Cosmetic Ingredients in the Hydra Assay

1990 ◽  
Vol 9 (3) ◽  
pp. 361-365 ◽  
Author(s):  
L.M. Newman ◽  
R.L. Giacobbe ◽  
L-J. Fu ◽  
E.M. Johnson
Keyword(s):  
Developmental Toxicity ◽  
Toxicity Testing ◽  
Potassium Sorbate ◽  
Toxicity Evaluation ◽  
False Negatives ◽  
Cosmetic Ingredients ◽  
In Utero Development ◽  
Developmental Toxicity Testing

The developmental toxicity hazard potential of six cosmetic products was determined in the in vitro Hydra assay. These studies were conducted to supplement available toxicological information and provide an indication of the priority of these compounds for higher level (in vivo) developmental toxicity testing. All but one ingredient, potassium sorbate, was predicted by the assay to be generally equally or more toxic to adults than to embryos and, therefore, to be low-priority chemicals for more elaborate tests. In contrast, assay results suggest that potassium sorbate is a prime candidate for higher-level animal developmental toxicology testing. The endpoints for this in vitro prescreen were ‘set’ some years ago to avoid false negatives as much as possible, but approximately 7% false positives result. Therefore, it is premature to consider sorbate as being uniquely hazardous to in utero development until this is established by testing in pregnant laboratory mammals.

scholarly journals Transmission of prion infectivity from blood by peptoid-conjugated beads

2019 ◽  
Author(s):  
Simone Hornemann ◽  
Petra Schwarz ◽  
Elisabeth J. Rushing ◽  
Michael D. Connolly ◽  
Ronald N. Zuckermann ◽  
...  
Keyword(s):  
False Negative ◽  
Transmitted Disease ◽  
Body Fluids ◽  
Protein Assay ◽  
Prion Infectivity ◽  
Negative Results ◽  
False Negative Results ◽  
Presymptomatic Stage ◽  
Positively Charged

AbstractPrions cause transmissible infectious diseases in humans and animals and have been found to be transmissible by blood transfusion even in the presymptomatic stage. However, the concentration of prions in body fluids such as blood and urine is extremely low, and therefore direct diagnostic tests on such specimens often yield false-negative results. Quantitative preanalytical prion enrichment may significantly improve the sensitivity of prion assays by concentrating trace amounts of prions from large volumes of body fluids. Here we show that beads conjugated to positively charged peptoids not only captured PrP aggregates from plasma of prion-infected hamsters, but also adsorbed prion infectivity in both the symptomatic and preclinical stages of the disease. Bead absorbed prion infectivity efficiently transmitted disease to transgenic indicator mice. We found that the readout of the peptoid-based misfolded protein assay (MPA) correlates closely with prion infectivity in vivo, thereby validating the MPA as a simple, quantitative, and sensitive surrogate indicator of the presence of prions. The reliable and sensitive detection of prions in plasma will enable a wide variety of applications in basic prion research and diagnostics.

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