Quantifying Processes Determining the Free Concentration of Phenanthrene in Basal Cytotoxicity Assays

2012 ◽  
Vol 25 (2) ◽  
pp. 436-445 ◽  
Author(s):  
Nynke I. Kramer ◽  
Mirna Krismartina ◽  
Ángeles Rico-Rico ◽  
Bas J. Blaauboer ◽  
Joop L. M. Hermens
Keyword(s):  
Free Concentration ◽  
Cytotoxicity Assays ◽  
Basal Cytotoxicity

Single Amino Acid Based Self-Assemblies of Cysteine and Methionine

2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acids ◽  
Neutral Condition ◽  
Single Amino Acid ◽  
Binding Assays ◽  
Human Neuroblastoma ◽  
Cytotoxicity Assays ◽  
First Time

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

102 Cord-blood derived NK cells, and CAR-T cells, an attractive improved immunotherapy treatment to be considered for hematological malignancies

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A113-A113
Author(s):  
Mireia Bachiller García ◽  
Lorena Pérez-Amill ◽  
Anthony Battram ◽  
Alvaro Urbano-Ispizua ◽  
Beatriz Martín-Antonio
Keyword(s):  
T Cells ◽  
Tumor Cell ◽  
Cord Blood ◽  
Immune Cells ◽  
In Vivo Models ◽  
Cell Clusters ◽  
Cytotoxicity Assays ◽  
Anti Tumor Activity

BackgroundMultiple myeloma (MM) remains an incurable hematological malignancy where a proportion of patients relapse or become refractory to current treatments. Administration of autologous T cells modified with a chimeric antigen receptor (CAR) against B cell maturation antigen (BCMA) has achieved high percentages of complete responses. Unfortunately, the lack of persistence of CART-BCMA cells in the patient leads to relapses. On the other side, cord-blood derived natural killer cells (CB-NK) is an off-the-shelf cellular immunotherapy option to treat cancer patients with high potential due to their anti-tumor activity. However, clinical results in patients up to date have been sub-optimal. Whereas CB-NK are innate immune cells and their anti-tumor activity is developed in a few hours, CART cells are adaptive immune cells and their activity develops at later time points. Moreover, we previously described that CB-NK secrete inflammatory proteins that promote the early formation of tumor-immune cell clusters bringing cells into close contact and thus, facilitating the anti-tumor activity of T cells. Therefore, we hypothesized that the addition of a small number of CB-NK to CART cells would improve the anti-tumor activity and increase the persistence of CART cells.MethodsT cells transduced with a humanized CAR against BCMA and CB-NK were employed at 1:0.5 (CART:CB-NK) ratio. Cytotoxicity assays, activation markers and immune-tumor cell cluster formation were evaluated by flow cytometry and fluorescence microscopy. In vivo models were performed in NSG mice.ResultsThe addition of CB-NK to CART cells demonstrated higher anti-MM efficacy at low E:T ratios during the first 24h and in long-term cytotoxicity assays, where the addition of CB-NK to CART cells achieved complete removal of tumor cells. Analysis of activation marker CD69 and CD107a degranulation from 4h to 24h of co-culturing proved differences only at 4h, where CD69 and CD107a in CART cells were increased when CB-NK were present. Moreover, CB-NK accelerated an increased formation of CART-tumor cell clusters facilitating the removal of MM cells. Of note, CB-NK addition did not increase total TNFα and IFNγ production. Finally, an in vivo model of advanced MM with consecutive challenge to MM cells evidenced that the addition of CB-NK achieved the highest efficacy of the treatment.ConclusionsOur results suggest that the addition of ‘off-the-shelf’ CB-NK to CART cells leads to a faster and earlier immune response of CART cells with higher long-term maintenance of the anti-tumor response, suggesting this combinatorial therapy as an attractive immunotherapy option for MM patients.

scholarly journals Newly Isolated Animal Pathogen Corynebacterium silvaticum Is Cytotoxic to Human Epithelial Cells

2021 ◽  
Vol 22 (7) ◽  
pp. 3549
Author(s):  
Jens Möller ◽  
Anne Busch ◽  
Christian Berens ◽  
Helmut Hotzel ◽  
Andreas Burkovski
Keyword(s):  
Cell Lines ◽  
Galleria Mellonella ◽  
Roe Deer ◽  
Electric Resistance ◽  
Human Epithelial Cell ◽  
Cytotoxicity Assays ◽  
Corynebacterium Ulcerans ◽  
Invertebrate Animal ◽  
Epithelial Cell Lines ◽  
Microscopy Measurement

Corynebacterium silvaticum is a newly identified animal pathogen of forest animals such as roe deer and wild boars. The species is closely related to the emerging human pathogen Corynebacterium ulcerans and the widely distributed animal pathogen Corynebacterium pseudotuberculosis. In this study, Corynebacterium silvaticum strain W25 was characterized with respect to its interaction with human cell lines. Microscopy, measurement of transepithelial electric resistance and cytotoxicity assays revealed detrimental effects of C. silvaticum to different human epithelial cell lines and to an invertebrate animal model, Galleria mellonella larvae, comparable to diphtheria toxin-secreting C. ulcerans. Furthermore, the results obtained may indicate a considerable zoonotic potential of this newly identified species.

Analogy Models for Prediction of Human Toxicity

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 103-116
Author(s):  
Sven Hellberg ◽  
Lennart Eriksson ◽  
Jörgen Jonsson ◽  
Fredrik Lindgren ◽  
Michael Sjöström ◽  
...  
Keyword(s):  
Human Subjects ◽  
Toxicity Testing ◽  
In Vitro Cytotoxicity ◽  
Alternative Methods ◽  
Laboratory Animals ◽  
In Vitro Tests ◽  
Human Toxicity ◽  
Efficient Data ◽  
Basal Cytotoxicity

Estimating the toxicity to humans of chemicals by testing on human subjects is not considered to be ethically acceptable, and toxicity testing on laboratory animals is also questionable. Therefore, there is a need for alternative methods that will give estimates of various aspects of human toxicity. Batteries of in vitro tests, together with physicochemical and toxicokinetic data, analysed by efficient data analytical methods, may enable analogy models to be constructed that can predict human toxicity. It may be possible to model non-specific toxicity relating to lipophilicity, or basal cytotoxicity, for a series of diverse compounds with large variation in chemical structure and physicochemical properties. However, local models for a series of similar compounds are generally expected to be more accurate, as well as being capable of modelling more-specific interactions. Analogy models for the prediction of human toxicity are discussed and exemplified with physicochemical and cytotoxicity data from the first ten chemicals in the multicenter evaluation of in vitro cytotoxicity (MEIC) project.

scholarly journals Structure modification, antialgal, antiplasmodial, and toxic evaluations of a series of new marine-derived 14-membered resorcylic acid lactone derivatives

2021 ◽  
Author(s):  
Wei-Feng Xu ◽  
Na-Na Wu ◽  
Yan-Wei Wu ◽  
Yue-Xuan Qi ◽  
Mei-Yan Wei ◽  
...  
Keyword(s):  
Positive Control ◽  
Structure Modification ◽  
Inhibitory Effects ◽  
Cytotoxicity Assays ◽  
Structure Activity ◽  
Novel Drugs ◽  
Systematic Strategy ◽  
Nmr Techniques ◽  
Acid Lactone ◽  
Drug Leads

AbstractMarine natural products play critical roles in the chemical defense of many marine organisms and are essential, reputable sources of successful drug leads. Sixty-seven 14-membered resorcylic acid lactone derivatives 3–27 and 30–71 of the natural product zeaenol (1) isolated from the marine-derived fungus Cochliobolus lunatus were semisynthesized by chlorination, acylation, esterification, and acetalization in one to three steps. The structures of these new derivatives were established by HRESIMS and NMR techniques. All the compounds (1–71) were evaluated for their antialgal and antiplasmodial activities. Among them, 14 compounds displayed antifouling activities against adhesion of the fouling diatoms. In particular, 9 and 34 exhibited strong and selective inhibitory effects against the diatoms Navicula laevissima and Navicula exigua (EC50 = 6.67 and 8.55 μmol/L), respectively, which were similar in efficacy to those of the positive control SeaNine 211 (EC50 = 2.90 and 9.74 μmol/L). More importantly, 38, 39, and 69–71 showed potent antiplasmodial activities against Plasmodium falciparum with IC50 values ranging from 3.54 to 9.72 μmol/L. Very interestingly, the five antiplasmodial derivatives displayed non-toxicity in the cytotoxicity assays and the zebrafish embryos model, thus, representing potential promising antiplasmodial drug agents. The preliminary structure–activity relationships indicated that biphenyl substituent at C-2, acetonide at positions C-5′ and C-6′, and tri- or tetra-substituted of acyl groups increased the antiplasmodial activity. Therefore, combining evaluation of chemical ecology with pharmacological models will be implemented as a systematic strategy, not only for environmentally friendly antifoulants but also for structurally novel drugs.

Polydopamine and dopamine interfere with tetrazolium-based cytotoxicity assays and produce exaggerated cytocompatibility inferences

2021 ◽  
Author(s):  
Anand Kumar Awasthi ◽  
Sakshi Gupta ◽  
Kavthekar Rupesh Namdev ◽  
Aditi Banerjee ◽  
Aasheesh Srivastava
Keyword(s):  
Cell Viability ◽  
Trypan Blue ◽  
Reliable Estimate ◽  
Trypan Blue Exclusion ◽  
Cytotoxicity Assays ◽  
Trypan Blue Exclusion Assay

Polydopamine (PDA) and dopamine (DA) can spontaneously reduce MTT reagent to formazan, resulting in incorrect cell-viability inferences. The non-redox Trypan Blue exclusion assay provides a more reliable estimate of cell viability with PDA and DA.

scholarly journals Functional Inequalities for Two-Level Concentration

2021 ◽  
Author(s):  
Franck Barthe ◽  
Michał Strzelecki
Keyword(s):  
Sobolev Inequality ◽  
Poincaré Inequality ◽  
Logarithmic Sobolev Inequality ◽  
Probability Measures ◽  
Exponential Rate ◽  
Functional Inequalities ◽  
Concentration Inequality ◽  
Poincare Inequality ◽  
Free Concentration ◽  
Concentration Property

AbstractProbability measures satisfying a Poincaré inequality are known to enjoy a dimension-free concentration inequality with exponential rate. A celebrated result of Bobkov and Ledoux shows that a Poincaré inequality automatically implies a modified logarithmic Sobolev inequality. As a consequence the Poincaré inequality ensures a stronger dimension-free concentration property, known as two-level concentration. We show that a similar phenomenon occurs for the Latała–Oleszkiewicz inequalities, which were devised to uncover dimension-free concentration with rate between exponential and Gaussian. Motivated by the search for counterexamples to related questions, we also develop analytic techniques to study functional inequalities for probability measures on the line with wild potentials.

scholarly journals The determination of binding parameters when the total and free substrate concentrations are not approximately equal

1979 ◽  
Vol 179 (3) ◽  
pp. 697-700 ◽  
Author(s):  
N Gains
Keyword(s):  
Substrate Concentration ◽  
Graphical Method ◽  
Enzyme Concentration ◽  
Binding Parameters ◽  
Free Concentration ◽  
Equilibrium Binding ◽  
Substrate Concentrations

By using a standard graphical method values of Km and V may be found that are independent of the conditions and assumptions that the total substrate concentration approximates to its free concentration and that Km is much larger than the enzyme concentration. The procedure is also applicable to the determination of equilibrium binding parameters of a ligand to a macromolecule.

Comparative study of a new composite biomaterial fluor-hydroxyapatite on fibroblast cell line NIH-3T3 by direct test

Biologia ◽  
2008 ◽  
Vol 63 (2) ◽  
Author(s):  
Marica Theiszová ◽  
Soňa Jantová ◽  
Silvia Letašiová ◽  
Ľuboš Valík ◽  
Martin Palou
Keyword(s):  
Comparative Study ◽  
Cell Line ◽  
Dna Content ◽  
Fibroblast Cell ◽  
Cell Number ◽  
Fibroblast Cell Line ◽  
3T3 Cells ◽  
End Points ◽  
Basal Cytotoxicity ◽  
Nih 3T3

AbstractThe number of biomaterials used in biomedical applications has rapidly increased in the past two decades. Fluorapatite (FA) is one of the inorganic constituents of bone or teeth used for hard tissue repairs and replacements. Fluor-hydroxyapatite (FHA) is a new synthetically prepared composite that in its structure contains the same molecular concentration of OH− groups and F− ions. The aim of this experimental investigation was to use the embryonal mouse fibroblast cell line NIH-3T3 for comparative study of basal cytotoxicity of fluoridated biomaterials FHA and FA discs. Hydroxyapatite (HA) disc, high-density polyethylene as negative control and polyvinyl chloride (PVC) containing organotin stabilizer as positive control were used as standard biomaterials. The appropriateness of the use of NIH-3T3 cells and their sensitivity for tested biomaterials were evaluated on the basis of five cytotoxic end points: cell proliferation, cell morphology, lactate dehydrogenase (LDH) released, protein and DNA cell content. The basal cytotoxicity of FHA, FA and HA discs was measured by direct contact method. FHA composite, FA and HA demonstrated in cell line NIH-3T3 nearly similar basal cytotoxicity increasing with the time of treatment. After 72 h of biomaterials treatment, about 25% inhibition of cell number, unchanged morphology of dividing cells, 6.31–0.16% increase of released LDH, about 10% inhibition of cell protein content and about 20% inhibition of DNA content was found. On the other hand, from the growth rates it resulted that NIH-3T3 cells, affected by tested biomaterials, divided about 20% slowlier than the control (untreated cells). Using the linear regression analysis we found out that deviations in measurements of cytotoxicity by four methods were as follows: less than 10% for cell number, protein and DNA content methods and 12.4% for released LDH method. Based on a good correlation of the cytotoxicity of biomaterials obtained from all end points we could conclude that fibroblast NIH-3T3 cell line was appropriate for measuring the basal cytoxicity of tested biomaterials.

High-throughput 3-D cell-based proliferation and cytotoxicity assays for drug screening and bioprocess development

2011 ◽  
Vol 151 (2) ◽  
pp. 186-193 ◽  
Author(s):  
Xudong Zhang ◽  
Shang-Tian Yang
Keyword(s):  
High Throughput ◽  
Drug Screening ◽  
Bioprocess Development ◽  
Cytotoxicity Assays ◽  
D Cell
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