The Hypo-Osmotic Swelling Test: Is it a Sperm Vitality or a Viability Assay?

Background: Lectins have been studied in recent years due to their immunomodulatory activities. Objective: We purified a lectin named OniL from tilapia fish (Oreochromis niloticus) and here we analyzed the cell proliferation and cytokine production in Balb/c mice splenocytes. Methods: Cells were stimulated in vitro in 24, 48, 72 hours and 6 days with different concentrations of OniL and Con A. Evaluation of cell proliferation was performed through [3H]-thymidine incorporation, cytokines were investigated using ELISA assay and cell viability assay was performed by investigation of damage through signals of apoptosis and necrosis. Results: OniL did not promote significant cell death, induced high mitogenic activity in relation to control and Con A and stimulated the cells to release high IL-2 and IL-6 cytokines. Conclusion: These findings suggest that, like Con A, OniL lectin can be used as a mitogenic agent in immunostimulatory assays.

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Investigation on the antibacterial activity of electronic cigarette liquids (ECLs): a proof of concept study

Current Pharmaceutical Biotechnology ◽

10.2174/1389201021666200903121624 ◽

2020 ◽

Vol 21 ◽

Cited By ~ 1

Author(s):

Virginia Fuochi ◽

Massimo Caruso ◽

Rosalia Emma ◽

Aldo Stivala ◽

Riccardo Polosa ◽

...

Keyword(s):

Antibacterial Activity ◽

Bacterial Species ◽

A549 Cells ◽

Bactericidal Effect ◽

Minimal Bactericidal Concentration ◽

Viability Assay ◽

Dependent Inhibition ◽

Dose Dependent Inhibition ◽

Dose Dependent

Background: The key ingredients of e-cigarettes liquid are commonly propane-1,2-diol (also called propylene glycol) and propane-1,2,3-triol (vegetal glycerol) and their antimicrobial effects are already established. The nicotine and flavors which are often present in e-liquids can interfere with the growth of some microorganisms. Objective: The effect of the combining these elements in e-liquids is unknown. The aim of the study was to investigate the possible effects of these liquids on bacterial growth in the presence or absence of nicotine and flavors. Methods: Susceptibilities of pathogenic strains (Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Enterococcus faecalis and Sarcina lutea) were studied by means of a multidisciplinary approach. Cell viability and antioxidant assays were also evaluated. Results: All e-liquids investigated showed antibacterial activity against at least one pathogenic strain. A higher activity was correlated to the presence of flavors and nicotine. Discussion: In most cases the value of minimal bactericidal concentration is equal to the value of minimal inhibitory concentration showing that these substances have a bactericidal effect. This effect was observed in concentrations up to 6.25% v/v. Antioxidant activity was also correlated to presence of flavors. Over time, the viability assay in human epithelial lung A549 cells showed a dose-dependent inhibition of cell growth. Conclusion: Our results have shown that flavors considerably enhance the antibacterial activity of propane-1,2-diol and propane-1,2,3-triol. This study provides important evidence that should be taken into consideration in further investigative approaches, to clarify the different sensitivity of the various bacterial species to e-liquids, including the respiratory microbiota, to highlight the possible role of flavors and nicotine.

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Do We have a Satisfactory Cell Viability Assay? Review of the Currently Commercially-Available Assays

Current Drug Discovery Technologies ◽

10.2174/1570163815666180925095433 ◽

2020 ◽

Vol 17 (1) ◽

pp. 2-22 ◽

Cited By ~ 3

Author(s):

Abdel-Baset Halim

Keyword(s):

Cell Viability ◽

Data Interpretation ◽

Positive Control ◽

Live Cells ◽

Proof Of Concept ◽

Cell Viability Assay ◽

Viability Assay ◽

Current Cell ◽

Dying Cells ◽

Differential Permeability

:Cell-based assays are an important part of the drug discovery process and clinical research. One of the main hurdles is to design sufficiently robust assays with adequate signal to noise parameters while maintaining the inherent physiology of the cells and not interfering with the pharmacology of target being investigated.:A plethora of assays that assess cell viability (or cell heath in general) are commercially available and can be classified under different categories according to their concepts and principle of reactions. The assays are valuable tools, however, suffer from a large number of limitations. Some of these limitations can be procedural or operational, but others can be critical as those related to a poor concept or the lack of proof of concept of an assay, e.g. those relying on differential permeability of dyes in-and-out of viable versus compromised cell membranes. While the assays can differentiate between dead and live cells, most, if not all, of them can just assess the relative performance of cells rather than providing a clear distinction between healthy and dying cells. The possible impact of relatively high molecular weight dyes, used in most of the assay, on cell viability has not been addressed. More innovative assays are needed, and until better alternatives are developed, setup of current cell-based studies and data interpretation should be made with the limitations in mind. Negative and positive control should be considered whenever feasible. Also, researchers should use more than one orthogonal method for better assessment of cell health.

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Under pressure: Hydrogel swelling in a granular medium

Science Advances ◽

10.1126/sciadv.abd2711 ◽

2021 ◽

Vol 7 (7) ◽

pp. eabd2711

Author(s):

Jean-François Louf ◽

Nancy B. Lu ◽

Margaret G. O’Connell ◽

H. Jeremy Cho ◽

Sujit S. Datta

Keyword(s):

Oil Recovery ◽

Granular Medium ◽

Granular Media ◽

Three Dimensional ◽

Osmotic Swelling ◽

Widespread Adoption ◽

Dry Soil ◽

Hydrogel Swelling

Hydrogels hold promise in agriculture as reservoirs of water in dry soil, potentially alleviating the burden of irrigation. However, confinement in soil can markedly reduce the ability of hydrogels to absorb water and swell, limiting their widespread adoption. Unfortunately, the underlying reason remains unknown. By directly visualizing the swelling of hydrogels confined in three-dimensional granular media, we demonstrate that the extent of hydrogel swelling is determined by the competition between the force exerted by the hydrogel due to osmotic swelling and the confining force transmitted by the surrounding grains. Furthermore, the medium can itself be restructured by hydrogel swelling, as set by the balance between the osmotic swelling force, the confining force, and intergrain friction. Together, our results provide quantitative principles to predict how hydrogels behave in confinement, potentially improving their use in agriculture as well as informing other applications such as oil recovery, construction, mechanobiology, and filtration.

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Paracetamol modulates biofilm formation in Staphylococcus aureus clonal complex 8 strains

Scientific Reports ◽

10.1038/s41598-021-84505-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Andi R. Sultan ◽

Kirby R. Lattwein ◽

Nicole A. Lemmens-den Toom ◽

Susan V. Snijders ◽

Klazina Kooiman ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Biofilm Formation ◽

Fluorescent Protein ◽

Clonal Complex ◽

Regulatory Pathways ◽

Immune Modulator ◽

Viability Assay ◽

Analgesic Agents ◽

Green Fluorescent

AbstractStaphylococcus aureus biofilms are a major problem in modern healthcare due to their resistance to immune system defenses and antibiotic treatments. Certain analgesic agents are able to modulate S. aureus biofilm formation, but currently no evidence exists if paracetamol, often combined with antibiotic treatment, also has this effect. Therefore, we aimed to investigate if paracetamol can modulate S. aureus biofilm formation. Considering that certain regulatory pathways for biofilm formation and virulence factor production by S. aureus are linked, we further investigated the effect of paracetamol on immune modulator production. The in vitro biofilm mass of 21 S. aureus strains from 9 genetic backgrounds was measured in the presence of paracetamol. Based on biofilm mass quantity, we further investigated paracetamol-induced biofilm alterations using a bacterial viability assay combined with N-Acetylglucosamine staining. Isothermal microcalorimetry was used to monitor the effect of paracetamol on bacterial metabolism within biofilms and green fluorescent protein (GFP) promoter fusion technology for transcription of staphylococcal complement inhibitor (SCIN). Clinically relevant concentrations of paracetamol enhanced biofilm formation particularly among strains belonging to clonal complex 8 (CC8), but had minimal effect on S. aureus planktonic growth. The increase of biofilm mass can be attributed to the marked increase of N-Acetylglucosamine containing components of the extracellular matrix, presumably polysaccharide intercellular adhesion. Biofilms of RN6390A (CC8) showed a significant increase in the immune modulator SCIN transcription during co-incubation with low concentrations of paracetamol. Our data indicate that paracetamol can enhance biofilm formation. The clinical relevance needs to be further investigated.

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SPARC regulates ferroptosis induced by sorafenib in human hepatocellular carcinoma

Cancer Biomarkers ◽

10.3233/cbm-200101 ◽

2021 ◽

pp. 1-9

Author(s):

Hong-Wei Hua ◽

Hao-Sheng Jiang ◽

Ling Jia ◽

Yi-Ping Jia ◽

Yu-Lan Yao ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Molecular Mechanism ◽

Cancer Progression ◽

Hepg2 Cells ◽

Cytotoxic Effect ◽

Cell Viability Assay ◽

Viability Assay ◽

Ldh Release ◽

Related Proteins ◽

Hcc Cells

BACKGROUND: Secreted protein acidic and rich in cysteine (SPARC) is implicated in cancer progression, but its role and associated molecular mechanism in the sorafenib sensitivity of hepatocellular carcinoma cells (HCC) remains elusive. METHODS: Human HCC cell lines Hep3B and HepG2 were treated with sorafenib alone or combined with activator or inhibitor of ferroptosis. Cell viability assay, reactive oxygen species (ROS) assay, lactate dehydrogenase (LDH) assay and western blot were used to study the regulatory mechanism of SPARC on HCC cells. RESULTS: Overexpression of SPARC enhanced the cytotoxic effect of sorafenib in Hep3B and HepG2 cells compared with parental cells. Depletion of SPARC decreased the cytotoxic effect of sorafenib in Hep3B and HepG2 cells compared with parental cells. Moreover, overexpression of SPARC significantly induced LDH release, whereas depletion of SPARC suppressed the release of LDH in Hep3B and HepG2 cells. Inhibition of ferroptosis exerted a clear inhibitory role against LDH release, whereas activation of ferroptosis promoted the release of LDH in HCC cells, as accompanied with deregulated expression of ferroptosis-related proteins. Furthermore, overexpression of SPARC induced oxidative stress, whereas depletion of SPARC suppressed the production of ROS. Deferoxamine (DFX)-induced inhibition of ferroptosis suppressed the production of ROS, while activation of ferroptosis promoted the contents of ROS in HCC cells exposed to sorafenib. CONCLUSION: Our findings give a better understanding of ferroptosis and its molecular mechanism in HCC cells that is regulated by SPARC in response to sorafenib.

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