Establishment of an In Vitro Photoallergy Test Using NCTC2544 Cells and IL-18 Production

Differentiation between photoallergenic and phototoxic reactions induced by low molecular weight compounds represents a current problem. The use of eratinocytes as a potential tool for the detection of photoallergens as opposed to photoirritants is considered an interesting strategy for developing in vitro methods. We have previously demonstrated the possibility to use the human keratinocyte cell line NCTC2455 and the production of interleukin-18 (IL-18) to screen low molecular weight sensitizers. The purpose of this work was to explore the possibility to use the NCTC2544 assay to identify photoallergens and discriminate from phototoxic chemicals. First, we identified suitable condition of UV-irradiation (3.5 J/cm2) by investigating the effect of UVAirradiation on intracellular IL-18 on untreated or chloropromazine (a representative phototoxic compound)- treated NCTC2544 cells. Then, the effect of UVA-irradiation over NCTC2544 cells treated with increasing concentrations of 15 compounds including photoallergens (benzophenone, 4-ter-butyl-4-methoxydibenzoylmethane, 2-ethylexyl-p-methoxycinnamate, ketoprofen, 6-methylcumarin); photoirritant and photoallergen (4-aminobenzoic acid, chlorpromazine, promethazine); photoirritants (acridine, ibuprofen, 8-methoxypsoralen, retinoic acid); and negative compounds (lactic acid, SDS and p-phenilendiamine) was investigated. Twenty-four hours after exposure, cytotoxicity was evaluated by the MTT assay or LDH leakage, while ELISA was used to measure the production of IL-18. At the maximal concentration assayed with non-cytotoxic effects (CV80 under irradiated condition), all tested photoallergens induced a significant and a dose-dependent increase of intracellular IL-18 following UVA irratiation, whereas photoirritants failed. We suggest that this system may be useful for the in vitro evaluation of the photoallergic potential of chemicals.

Vespignani, Giorgio, Iппoδρoμoς. Il circo di Costantinopoli nuova Roma dalla realtà alla storiografia, Fondazione Centro Italiano di Studi sull"Alto Medioevo, Spoleto, 2010, 303 páginas. ISBN: 978 88-7988-197-5

"El Circo Máximo es su templo, su hogar, su asamblea y la esperanza de todos sus deseos" (AmmiAnvs mArc., Res gest., XXVIII, 4, 29: eisque templum et habitaculum et contio et cupitorum spes omnis Circus est maximus). De este modo describió el historiador Amiano Marcelino, hacia el 382/397, la pasión que la plebe de Roma sentía hacia los espectáculos, especialmente hacia los ludi circenses. Se trata de una afición que se fue incrementando a lo largo de toda la historia del Imperio Romano, hasta el extremo que a mediados del siglo iv, según el calendario de Filócalo (CIL, I2, 1, p. 256-278), se alcanzaron los 177 días de juegos anuales. Y evidentemente tal apasionamiento no fue exclusivo de la ciudad de Roma, sino que se vivió de un modo común en todo el Imperio, sobre todo en las ciudades más grandes, entre las que destacó de una manera especial la capital de Oriente, Constantinopla, la nueva Roma fundada por Constantino I.

Establishment of an in vitro photoassay using THP-1 cells and IL-8 to discriminate photoirritants from photoallergens

At present, there are no in vivo or in vitro methods developed which has been adopted by regulatory authorities to assess photosensitization induced by chemicals. Recently, we have proposed the use of THP-1 cells and IL-8 release to identify the potential of chemicals to induce skin sensitization. Based on the assumption that sensitization and photosensitization share common mechanisms, the aim of this work was to explore the THP-1 model as an in vitro model to identify photoallergenic chemicals. THP-1 cells were exposed to 7 photoallergens and 3 photoirritants and irradiated with UVA light or kept in dark. Non phototoxic allergens or irritants were also included as negative compounds. Following 24 h of incubation, cytotoxicity and IL-8 release were measured. At subtoxic concentrations, photoallergens produced a dose-related increase in IL-8 release after irradiation. Some photoirritants also produced a slight increase in IL-8 release. However, when the overall stimulation indexes of IL-8 were calculated for each chemical, 6 out of 7 photoallergens tested reached a stimulation index above 2, while the entire set of negative compounds had stimulation indexes below 2. Our data suggest that this assay may become a useful cell-based in vitro test for evaluating the photosensitizing potential of chemicals.

“L’Emozione di conoscere e il desiderio di esistere”: Què és i com afecta la seva pràctica en el desenvolupament de l'autonomia de l'infant

El treball que es presenta a continuació pretén fer un aprofundiment en la metodologia pedagògica “Emozione di conoscere e desiderio di esistere”, nascuda a Itàlia i usada com a referent en l’Educació Especial, amb la intensió de poder valorar de quina manera afecta la seva pràctica en el desenvolupament de l’autonomia de l’infant. Per fer-ho, s’ha fet un recull dels estudis més rellevants relacionats amb el mètode “Emozione di conocscere” i amb el concepte d’autonomia. Seguidament, s’ha fet una observació acurada per poder descriure la posada en pràctica d’un projecte basat en aquesta metodologia i analitzar com aquest intervé en desenvolupar dita competència en els alumnes. Tot això, emmarcat dins l’escenari de la “Scuola Elementare Pirazzini”, situada al centre – nord d’Itàlia.