: Matériaux de cours issus des formations Mutual Heritage

Cet ouvrage fait partie du projet Mutual Heritage : from historical integration to contemporary active participation, un projet sur la patrimoine architectural et urbain récent dans le monde méditerranéen. Il rassemble des matériaux de cours issus d'une de ses formations

Dose-Dependent ATP Depletion and Cancer Cell Death following Calcium Electroporation, Relative Effect of Calcium Concentration and Electric Field Strength

Background: Electroporation, a method for increasing the permeability of membranes to ions and small molecules, is used in the clinic with chemotherapeutic drugs for cancer treatment (electrochemotherapy). Electroporation with calcium causes ATP (adenosine triphosphate) depletion and cancer cell death and could be a novel cancer treatment. This study aims at understanding the relationship between applied electric field, calcium concentration, ATP depletion and efficacy. Methods: In three human cell lines — H69 (small-cell lung cancer), SW780 (bladder cancer), and U937 (leukaemia), viability was determined after treatment with 1, 3, or 5 mM calcium and eight 99 μs pulses with 0.8, 1.0, 1.2, 1.4 or 1.6 kV/cm. Fitting analysis was applied to quantify the cell-killing efficacy in presence of calcium. Post-treatment intracellular ATP was measured in H69 and SW780 cells. Post-treatment intracellular ATP was observed with fluorescence confocal microscopy of quinacrine-labelled U937 cells. Results: Both H69 and SW780 cells showed dose-dependent (calcium concentration and electric field) decrease in intracellular ATP (

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Meningeal chondroblastic osteosarcoma: case report and review of the literature

International audiencePrimary meningeal osteosarcomas are exceedingly rare. We report a case of a 51-year-old man with a chondroblastic osteosarcoma treated with pre-operative embolization, surgical removal, followed by adjuvant chemotherapy and radiation therapy. Patient is alive without any recurrence 43 months after diagnosis

Maturation of pre‐40S particles in yeast and humans

International audienc

Viability of H69 and SW780 cells after calcium electroporation.

<p>Viability, assessed using MTS assay, of H69, a human small cell lung cancer cell line (<b>A</b>); and SW780, a human bladder cancer cell line (<b>B</b>) 24 hours after treatment with calcium electroporation. Final extracellular calcium concentrations of 0 mM, 1 mM, 3 mM, or 5 mM and applied electric field of either 0.8 kV/cm, 1.0 kV/cm, or 1.2 kV/cm. Cells thrice thawed and frozen, then sonicated were used as control (dead cells). Results are illustrated as percentage of control (no electroporation, no added calcium), electroporation (EP), mean + S.D., n = 6.</p

U937 cell response to calcium electroporation.

<p>U937, a human leukaemia cell line. (<b>A</b>) Cellular quinacrine fluorescence intensity of U937 15 min after calcium electroporation. The extracellular quinacrine concentration was 10 μM during loading and electroporation. Final extracellular calcium concentrations of 0 mM or 3 mM and applied electric field of 1.0 kV/cm were used. Columns depict the average of 180 cells (9 experiments × 20 cells). Arbitrary units (AU), mean + S.D., n = 9. (<b>B</b>) U937 cell viability measured 24 h after calcium electroporation. Viability assessed for U937 using resazurin cell proliferation assay. Extracellular calcium concentrations of 0 or 3 mM. Applied electric field of 1.0 kV/cm. Results are illustrated as percentage of control (no electroporation, no added calcium), mean + S.D., n = 6.</p

Scanning confocal images of U937 15 min after calcium electroporation.

<p>U937, a human leukaemia cell line. Final extracellular calcium chloride concentrations of 0 mM or 3 mM and applied electric field of 1.0 kV/cm. Quinacrine fluorescence (top row), 10 μM; propidium iodide fluorescence (middle row), 7.5 μM; phase contrast cell images (bottom row).</p