Validation of In Vitro Methods to Single Out Photoirritants Using Mechanistically Based Tests

1997 ◽  
pp. 239-247 ◽  
Author(s):  
Wolfgang J. W. Pape
Keyword(s):  
In Vitro Methods

Anti-amnesic activity screening of the seed ethanol extracts of Turkish Paeonia taxa by in vitro methods

Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
D Sevim ◽  
FS Senol ◽  
I Orhan ◽  
B Şener ◽  
E Kaya
Keyword(s):  
In Vitro Methods ◽  
Activity Screening ◽  
Ethanol Extracts

Analysis of antidepressant properties of some Papaver species by in vivo and in vitro methods

Planta Medica ◽  
2015 ◽  
Vol 81 (16) ◽  
Author(s):  
OML Bayazeid ◽  
F Yalcin ◽  
M İlhan ◽  
H Karahan ◽  
E Kupeli-Akkol ◽  
...  
Keyword(s):  
In Vitro Methods

The Effects of Some Synthetic Compounds on In Vitro Fibrinolytic Activity Measured by Different Methods and the Relevance to Activity In Vivo

1972 ◽  
Vol 28 (03) ◽  
pp. 351-358
Author(s):  
A.J Baillie ◽  
A. K Sim
Keyword(s):  
Inhibitory Activity ◽  
Substrate Concentration ◽  
Fibrinolytic Activity ◽  
Synthetic Compounds ◽  
In Vitro Methods ◽  
Narrow Concentration Range

SummaryThe activity of several synthetic compounds, rated from good to poor (or inactive) fibrinolytic activators, has been assessed by two different commonly-used in vitro methods. Compounds shown to be active over a narrow concentration range in the hanging clot test were shown to be inhibitors of plasmin and trypsin in the casein-olytic test. The inhibitory activity of these compounds was shown to increase with increasing substrate concentration and apparent activity in the hanging clot test. Possible explanations and relevance of these observations are discussed.

A Call for a European Prohibition of Monoclonal Antibody Production by the Ascites Procedure in Laboratory Animals

1998 ◽  
Vol 26 (4) ◽  
pp. 523-536
Author(s):  
Coenraad F.M. Hendriksen
Keyword(s):  
Monoclonal Antibody ◽  
Laboratory Animals ◽  
Induction Method ◽  
Therapeutic Application ◽  
Monoclonal Antibody Production ◽  
In Vitro Methods ◽  
Appeals Process ◽  
Core Facilities ◽  
Mab Production

Monoclonal antibodies (mAbs) are particularly valuable in therapeutics and research. Unfortunately, one of the most familiar methods of producing mAbs, the ascites induction method, causes pain and distress to the animals used. In most cases, non-animal or in vitro alternatives can be employed to reduce or eliminate the use of animals for mAb production. Prohibition of the use of animals in the production of mAbs is recommended, except when the replacement in vitro methods prove to be insufficient, and in a limited number of other well-documented cases, such as an exceptional need for an emergency therapeutic application. A total ban on the use of animals for mAb production is impractical and it is imperative that an appeals process should accompany the prohibition. The need for the establishment of core facilities for in vitro mAb production is emphasised.

In Vitro Methods for the Assessment of L-Cysteine Conjugate Toxicity

1994 ◽  
Vol 22 (2) ◽  
pp. 72-80
Author(s):  
Lorraine D. Buckberry ◽  
Harriet J. Adcock ◽  
Jeremy Adler ◽  
Ian S. Blagbrough ◽  
Peter J. Gaskin ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Mammalian Species ◽  
Mercapturic Acid ◽  
Assay Method ◽  
Cellular Toxicity ◽  
In Vitro Methods ◽  
Metabolic Route ◽  
Assay Methods ◽  
Chang Liver

L-Cysteine conjugates are normally metabolised via N-acetylation to produce a mercapturic acid. However, a recently identified metabolic route (C-S lysis) may lead to the generation of an unstable thiol which has been demonstrated to be responsible for toxicity in various mammalian species. Human Chang liver cells were challenged with a number of established L-cysteine conjugates. The cellular toxicity of these compounds was determined using a range of assay procedures, which provided differing information, depending on the assay method used. These observations were then investigated in order to establish which system would provide the most reliable indication of C-S lyase toxicity and whether any information on the mechanism of action could be obtained by these assay methods.

In Vitro Toxicology Methods in Risk Assessment

1996 ◽  
Vol 24 (3) ◽  
pp. 325-331
Author(s):  
Iain F. H. Purchase
Keyword(s):  
Risk Assessment ◽  
Hazard Assessment ◽  
Human Health Risk ◽  
In Vitro Test ◽  
In Vitro Methods ◽  
New Concepts ◽  
Vitro Test

The title of this paper is challenging, because the question of how in vitro methods and results contribute to human health risk assessment is rarely considered. The process of risk assessment usually begins with hazard assessment, which provides a description of the inherent toxicological properties of the chemical. The next step is to assess the relevance of this to humans, i.e. the human hazard assessment. Finally, information on exposure is examined, and risk can then be assessed. In vitro methods have a limited, but important, role to play in risk assessment. The results can be used for classification and labelling; these are methods of controlling exposure, analogous to risk assessment, but without considering exposure. The Ames Salmonella test is the only in vitro method which is incorporated into regulations and used widely. Data from this test can, at best, lead to classification of a chemical with regard to genotoxicity, but cannot be used for classification and labelling on their own. Several in vitro test systems which assess the topical irritancy and corrosivity of chemicals have been reasonably well validated, and the results from these tests can be used for classification. The future development of in vitro methods is likely to be slow, as it depends on the development of new concepts and ideas. The in vivo methods which currently have reasonably developed in vitro alternatives will be the easiest to replace. The remaining in vivo methods, which provide toxicological information from repeated chronic dosing, with varied endpoints and by mechanisms which are not understood, will be more difficult to replace.

Semen Cuscutae-Fructus Lycii improves spermatogenic dysfunction by repairing the blood-testis barrier in rats according to in silico and in vitro methods

2021 ◽  
pp. 114022
Author(s):  
Yutian Zhu ◽  
Lei Dong ◽  
Jingshang Wang ◽  
Qiuning Liu ◽  
Hongxuan Tong ◽  
...  
Keyword(s):  
In Silico ◽  
In Vitro Methods ◽  
Fructus Lycii ◽  
Blood Testis Barrier

Studies of Metabolism Mediated Mutagenicity In Vitro

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 243-250
Author(s):  
Dag Jenssen ◽  
Lennart Romert
Keyword(s):  
Cell Lines ◽  
Biological Effects ◽  
Animal Experiments ◽  
Culture Technique ◽  
Organ Perfusion ◽  
Isolated Cells ◽  
Toxicological Effect ◽  
In Vitro Methods

To understand the cause of the biological effects of xenobiotic metabolism in mammals, investigators have traditionally performed animal experiments by comparing the results of biochemical methods, such as measurement of enzyme activity analysis of the metabolites produced, with the observed toxicological effect. This article deals with in vitro methods for genotoxicity combined with drug metabolising preparations at the organelle, cell or organ levels, as exemplified by microsome preparations, isolated cells/cell lines and organ perfusion systems, respectively. The advantage of some of these methods for studying metabolism-mediated mutagenicity is that the measured endpoint reflects not only the bioactivating phase I reactions, but also the detoxifying phase II reactions, and the transfer of the non-conjugated reactive metabolites to other cells and their ability to cause mutations in these cells. In vivo, all these events are important factors in the initiation of cancer. A mechanistic advantage of the methods for metabolism-mediated mutagenicity in vitro is that the relevance of the different steps in metabolism for the mutational events can seldom be investigated in an in vivo assay. Furthermore, human studies can easily be performed using the co-culture technique with isolated human cells or cell lines.

The EYTEX™ System and the Neutral Red Uptake Inhibition Assay in Cultured Hep G2 Cells as Alternative Methods for In Vivo Eye Irritation Following the EEC Protocol

1990 ◽  
Vol 17 (4) ◽  
pp. 325-333
Author(s):  
Paul J. Dierickx ◽  
Virginia C. Gordon
Keyword(s):  
Neutral Red ◽  
Alternative Methods ◽  
Inhibition Assay ◽  
Hep G2 ◽  
Hep G2 Cells ◽  
Eye Irritation ◽  
Uptake Inhibition ◽  
In Vitro Methods ◽  
Neutral Red Uptake

The neutral red uptake inhibition assay and the EYTEX™ system were investigated as alternative methods for the assessment of eye irritation, determined according to the EEC protocol. The 17 test chemicals used were mainly organic solvents. The xenobiotics were applied to Hep G2 cells for 24 hours at different concentrations. Neutral red uptake inhibition was then measured. The results are expressed as the NI50 value, which is the concentration of test compound required to induce a 50% reduction in neutral red uptake. The same chemicals were also tested as coded samples by the EYTEX™ test according to the manufacturer's directions. A nearly identical quantitative correlation was found for both in vitro methods with corneal opacity scores: r = 0.84 for EYTEX™ scores and r = 0.83 for log NI50, expressed in μg/ml. Whilst these correlations are certainly not perfect, it is clear that both in vitro methods can be used as valuable prescreening methods.

scholarly journals Vitamin E-Coated Dialyzer Inhibits Oxidative Stress

2017 ◽  
Vol 44 (4) ◽  
pp. 288-293 ◽  
Author(s):  
Shiho Yamadera ◽  
Yuya Nakamura ◽  
Masahiro Inagaki ◽  
Isao Ohsawa ◽  
Hiromichi Gotoh ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vitamin E ◽  
Synthetic Polymer ◽  
Intracellular Reactive Oxygen Species ◽  
Ros Production ◽  
Oxygen Species ◽  
In Vitro Methods ◽  
Stress Effects ◽  
Intracellular Ros

Aim: To examine the effects of vitamin E-coated dialyzer on oxidative stress in vitro. Methods: A dialyzer with a synthetic polymer membrane (APS-11SA) and vitamin E-coated dialyzer (VPS-11SA) were connected to a blood tubing line, and U937 cells were circulated in the device. The circulating fluid was collected at 1, 2, 5, 10, 25, and 50 cycles, which are estimated numbers of passes through the dialyzer. Intracellular reactive oxygen species (ROS) production, malondialdehyde (MDA), and Cu/Zn-superoxide dismutase (SOD) were quantified. Results: Intracellular ROS production was increased in the first cycle by APS-11SA and was decreased throughout the experiment by VPS-11SA. Intracellular ROS production in the VPS-11SA device was lower, and MDA levels were decreased. MDA levels were lower during VPS-11SA processing than during APS-11SA processing. Cu/Zn-SOD levels remained unchanged. Conclusion: Our results highlight anti-oxidative-stress effects of a vitamin E-coated dialyzer.

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