in vitro testing Dotaz Zobrazit nápovědu
Hemocompatibility testing is essential for the safe use of medical devices that come into contact with blood. There are various evaluation methodologies. In vivo, ex vivo and in vitro systems can be used and different categories can be evaluated in different ways. This review deals with in vitro hemocompatibility testing mainly on the basis of ISO standard 10993-4 recommendations and possibly new research results. This is a summary of all tested categories, i.e. coagulation, hemolysis, hematology and activation of leukocytes and platelets and the complement system. The main principle of evaluation and the possibilities of testing using various methodologies are always described. In the next part, variants of the method of blood incubation with the tested medical device from the static system to the circulation are described. Circulation can be provided, for example, by means of the Chandler Loop or parallel-plate chambers.
- Klíčová slova
- Coagulation, Hemocompatibility, Human blood, Leukocyte, Platelet,
- MeSH
- hemokoagulace * MeSH
- hemolýza MeSH
- lidé MeSH
- techniky in vitro MeSH
- testování materiálů MeSH
- trombocyty * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
In vitro cytotoxicity testing is an indispensable part of the development of new biomaterials. However, the standard ISO 10993-5 enables variability in the testing conditions, which makes the results of the test incomparable. We studied the influence of media composition on the results of the cytotoxicity test. Solutions of ZnCl2 served as simulated extracts and we also used extracts of three types of Zn-based and Mg-based degradable metals. We incubated the cells with the solutions prepared in two types of media with two concentrations of serum (5 and 10%). We compared the toxic effect of the extracts on L929 murine fibroblast-derived cell line, which is recommended by ISO standard and on "osteoblast-like cells" U-2 OS. We also compared two methods of exposition: solutions were added either to a sub-confluent layer or to the cell suspension. We evaluated the metabolic activity of the cells using the resazurin test. We found out that in vitro cytotoxicity is dramatically influenced by the concentration of serum and by the type of the medium as well as by the type of exposition and type of cells. Therefore, when performing in vitro cytotoxicity testing of biomaterials, the authors should carefully specify the conditions of the test and comparison of different studies should be carried out with caution.
- MeSH
- biokompatibilní materiály farmakologie MeSH
- komplexní sloučeniny farmakologie MeSH
- kultivované buňky MeSH
- myši MeSH
- slitiny MeSH
- techniky in vitro MeSH
- testování materiálů MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biokompatibilní materiály MeSH
- komplexní sloučeniny MeSH
- slitiny MeSH
Despite widespread and prolonged use of adult novelties, their health safety is not regularly tested or legally regulated. In the EU, adult novelties are subjected to the General Product Safety Directive, placing the burden of proof regarding safe products onto the manufacturers. The aim of our pilot study was to expand knowledge on potential application of in vitro methods for hazard prediction of extracts from final products. We subjected extracts of 20 adult novelties, purchased on the Czech market to toxicological tests including NRU cytotoxicity assay, sensitization tests DPRA and LuSens and the YES/YAS endocrine assay. Four samples produced cytotoxicity. Sensitization potential was recorded by DPRA (three samples) while the LuSens reported ten samples. Regarding endocrine disruption, three samples produced antiestrogen and antiandrogen effects. Six samples exhibited androgenic potential and one sample showed estrogenic potential. Positive results with possible health effects were recorded repeatedly for samples made of ABS, PVC and latex. The study has confirmed promising usefulness of our test methods combination with regard to safety testing of this type of consumer products. The results should be evaluated with care, however, the data bring added-value to the limited knowledge of mixture toxicology and are indicative for further testing.
- Klíčová slova
- Chemical mixtures safety, Cytotoxicity, Endocrine disruption, In vitro toxicology, Public health, Risk assessment, Sex toy industry, Skin sensitization,
- MeSH
- buňky BALB 3T3 MeSH
- endokrinní disruptory toxicita MeSH
- fibroblasty účinky léků fyziologie MeSH
- hra a hračky * MeSH
- lidé MeSH
- myši MeSH
- pilotní projekty MeSH
- plastické hmoty toxicita MeSH
- Saccharomyces cerevisiae účinky léků fyziologie MeSH
- sexuální chování účinky léků fyziologie MeSH
- spotřebitelská bezpečnost produktů normy MeSH
- techniky in vitro metody MeSH
- testy akutní toxicity metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- endokrinní disruptory MeSH
- plastické hmoty MeSH
In our experiments we tested 11 kinds of different lignocellulose materials by means of the method in vitro according to Mellenberger et al. (1970) for a determination of their digestiblity. In experiments carried out with beech sawdust treated with 0.1 M of sulphuric acid a digestibility of 3.7% was found, in sawdust treated with 0.47 M of nitric acid a digestibility of 61.6% was found and after a neutralization with ammonia it amounted to 72.2%. Wood fibre (WF-1) treated enzymatically showed a digestibility of 28.6% and in the WF-2 complemented with newsprint paper it amounted to 33.4%. Untreated beech waste -- forest billets -- showed a low digestibility (5.6%) and that of zero fibre was somewhat higher (12.6%). Difibered beech sawdust showed a digestibility of 44.0% and the digestibility of the biomass prepared from lye waste obtained during the production of cellulose fibres amounted to 74.1%. Waste fibre also showed a high digestibility of 76.0%. Straw enriched with yeast proteins (SL-1) showed a digestibility of 58.0%. Cellulose used as a standard in the course of the testing of lignocellulose materials showed the highest digestibility -- 82.3%.
- MeSH
- celulosa * MeSH
- dřevo * MeSH
- lignin * MeSH
- techniky in vitro MeSH
- trávení * MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Názvy látek
- celulosa * MeSH
- lignin * MeSH
- Klíčová slova
- CELLS *, TISSUE CULTURE *,
- MeSH
- buňky * MeSH
- pojivová tkáň * MeSH
- techniky in vitro MeSH
- techniky tkáňových kultur * MeSH
- Publikační typ
- časopisecké články MeSH
Seven selected parabens (4 allowed, 3 banned in cosmetics) were tested in order to confirm and expand historical data on their toxicological properties and safety. The aim was to apply novel in vitro methods, which have been sufficiently technically and scientifically validated for the purposes of toxicological testing of chemicals. The study included several toxicological endpoints such as skin/eye irritation, skin sensitization, endocrine disruption and genotoxicity. The battery of selected methods comprised regulatory accepted EpiDerm™ skin model (OECD TG 439); EpiOcular™ corneal model (OECD TG 492) and scientifically valid test method HET-CAM (DB-ALM Protocol No. 47); in chemico test DPRA (OECD TG 442C); in vitro test LuSens (OECD TG 442D) and in vitro test h-CLAT (OECD TG 442E); Ames MPF™ (Xenometrix) and XenoScreen YES/YAS (Xenometrix). Overall, none of the 4 allowed parabens exhibited skin/eye irritation or genotoxicity. However, all allowed parabens in cosmetics were predicted as samples with potentially sensitizing properties in the LuSens and h-CLAT test methods, but not confirmed by DPRA. Endocrine disruption was recorded only at high concentrations, whereas methyl paraben and ethyl paraben exhibited the lowest activity. This study confirmed the safety of use of the allowed parabens in the highest recommended concentrations in cosmetics or pharmaceuticals.
- Klíčová slova
- Endocrine disruption, Genotoxicity, In vitro toxicology, Parabens, Phototoxicity, Sensitization, Skin and eye irritation,
- MeSH
- alternativy testů na zvířatech * metody MeSH
- kosmetické přípravky * toxicita MeSH
- kůže MeSH
- parabeny toxicita MeSH
- techniky in vitro MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- kosmetické přípravky * MeSH
- parabeny MeSH
Considerable research has been directed towards optimising in vitro tests that can diagnose resistance in pre-parasitic stages of parasites. The objective of this study was to compare the in vivo faecal egg count reduction test (FECRT), the in vitro egg hatch test (EHT), and the molecular determination of the frequency of a codon 200 allele of β-tubulin isotype 1 associated with benzimidazole resistance in larval stages of Haemonchus contortus obtained from infected goats. Animals were infected with composite infective doses representing 10, 20, 30, 40, 60, and 80% resistant alleles. Faecal samples for the EHT were collected on 28, 33, and 35 days post-infection. The results of the in vivo FECRT indicated that albendazole treatment reduced infections consisting of composite doses of 10, 20, 30, 40, 60, and 80% larvae of the resistant isolate by 91.3, 78.0, 63.3, 48.4, 36.5, and 41.4%, respectively. The drug concentration at which 50% of the eggs were prevented from developing hatching larvae (ED50) in the in vitro EHT varied from 0.09 ± 0.01 to 15.63 ± 12.10 μg/mL thiabendazole. The results of the in vitro EHT indicated that the test could estimate in vivo resistance well. The EHT could thus accurately estimate the in vivo efficacy of the drug and percentage of the resistance allele in the population using hatching parameters in delineation doses. This finding was also supported by comparing the FECRT data to the hatching percentages in the EHT on 30 goat farms in Slovakia with natural mixed infections of gastrointestinal parasites.
TITLE: Le test d’éclosion des œufs in vitro prédit-il l’échec du traitement au benzimidazole pour Haemonchus contortus ? ABSTRACT: Des efforts de recherche considérables ont été consacrés à l’optimisation des tests in vitro permettant de diagnostiquer la résistance des parasites aux stades préparasitaires. L’objectif de cette étude était de comparer le test de réduction du nombre d’œufs fécaux in vivo (TRNOF), le test d’éclosion des œufs in vitro (TEO) et la détermination moléculaire de la fréquence d’un allèle du codon 200 de l’isotype 1 de la β-tubuline associé à résistance au benzimidazole au stade larvaire d’Haemonchus contortus, obtenus à partir de chèvres infectées. Les animaux ont été infectés avec des doses infectieuses composites représentant 10, 20, 30, 40, 60 et 80 % d’allèles résistants. Des échantillons de matières fécales ont été prélevés pour le TEO aux jours 28, 33 et 35 après l’infection. Les résultats de la TRNOF in vivo ont indiqué que le traitement à l’albendazole réduisait respectivement de 91,3, 78,0, 63,3, 48,4, 36,5 et 41,4 % les infections composées de doses composites de 10, 20, 30, 40, 60 et 80 % de larves de l’isolat résistant. La concentration de médicament à laquelle 50 % des œufs ont été empêchés de développer des larves qui éclosent (DE50) dans le TEO in vitro variait de 0,09 ± 0,01 à 15,63 ± 12,10 μg/mL de thiabendazole. Les résultats du TEO in vitro ont indiqué que le test pouvait correctement estimer la résistance in vivo. Le TEO a ainsi pu estimer avec précision l’efficacité in vivo du médicament et le pourcentage de l’allèle de résistance dans la population en utilisant des paramètres d’éclosion dans les doses de délimitation. Cette constatation a également été étayée par la comparaison des données du TRNOF aux pourcentages d’éclosion dans le TEO sur 30 élevages de chèvres en Slovaquie, avec des infections mixtes naturelles de parasites gastro-intestinaux.
- Klíčová slova
- Anthelmintic resistance, Detection methods, Egg hatch test, Goats, Haemonchus contortus,
- MeSH
- anthelmintika * farmakologie terapeutické užití MeSH
- benzimidazoly farmakologie terapeutické užití MeSH
- feces MeSH
- Haemonchus * genetika MeSH
- léková rezistence MeSH
- nemoci ovcí * MeSH
- ovce MeSH
- počet parazitárních vajíček veterinární MeSH
- techniky in vitro MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- anthelmintika * MeSH
- benzimidazoly MeSH
- MeSH
- anestetika lokální metabolismus MeSH
- játra metabolismus MeSH
- králíci MeSH
- techniky in vitro MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- anestetika lokální MeSH
Tumorigenesis is always accompanied by alterations of the microenvironment in the respective tissue. The tumor microenvironment represents a heterogeneous complex, in which cell proliferation, differentiation, necrosis or apoptosis are regulated by various extracellular stimuli, and it can also lead to development of an aggressive phenotype of tumor cells. Influence of tumor microenvironment is also often connected with resistance to frequently used therapeutic procedures. Specifics of the tumor microenvironment are closely associated with the structural and functional abnormalities of tumor microvessels and altered cellular metabolism. Moreover, changes such as increase in glycolysis, elevated glucose uptake, production of lactate and CO2, and presence of hypoxic regions and regions with acidic pH are typical features of tumor tissues. At present, there is a lot of methods for in vitro simulation and investigation of some of these specific conditions, and a number of new methods are being developed. A detailed understanding of the specifics of the tumor microenvironment should increasingly improve the development of new treatment possibilities of human cancers.
- MeSH
- lidé MeSH
- nádorové mikroprostředí * MeSH
- techniky in vitro * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
The most dangerous aspect of cancer is the metastatic spread to other parts of the body. Cancer cells frequently use circulation to spread to secondary locations. By entering the blood-stream (in a process called intravasation) and by crossing the vessel walls at the metastatic sites (extravasation) tumor cells disseminate to distal organs and eventually form life threatening metastases. Crossing the vessel walls (transendothelial migration) is a vital step of metastatic cascade and the elucidation of mechanisms involved in transendothelial migration might inspire new strategies of targeted antimetastatic therapy. There are several methods to study transendothelial migration in living models (in vivo). Although they offer complex physiological microenvironment, they are expensive and technically demanding, therefore not widely used. As an alternative, sophisticated techniques to investigate transendothelial migration in vitro have been developed. They are generally more available and feasible, but there is still considerable variability in the difficulty of performance, the requirements for specialized devices, accuracy of in vivo simulation and relevance for oncological applications. The classification, various modifications, pros and cons of in vitro techniques for studying transendothelial migration are summarized in this review.
