1,721,307 research outputs found
Medicina e classificazione delle scienze
No full textNell'articolo si esamina il problema della collocazione della medicina nella classificazione delle scienze tra Seicento e Ottocento. Sono prese in considerazione le proposte di organizzazione del sapere, e del posto in esse assegnato alla medicina, da parte dei filosofi F. Bacon, R. Descartes, Chr. Wolff, dello scienziato A.-M. Ampère, del medico H. Boerhaave con riferimento alla classificazione della medicina, e dalle sistemazioni presentate nell'Encyclopaedia di J.H. Alsted e nell'Encyclopédie curata da D. Diderot e J. D'Alembert. Si precisa che sono stati scritti da A. Moretto l'Introduzione e i §§ 3, 4
Inibitori delle esterase e danno nervoso periferico : dalla clinica ai modelli sperimentali
No full textAcute reference doses: theory and practical approaches
No full textThe approach of the Joint Meeting on Pesticide Residues to the establishment of the acute reference dose for pesticides is presented and related issues are discussed. Three main points seem relevant when discussing the acute reference dose: (1) what compounds should have an acute reference dose, (2) what toxicological database is required for the establishment of an acute reference dose; (3) what safety factors are to be used. It is concluded that (1) groups of compounds that need an acute reference dose can be identified, whereas general rules for identifying groups not requiring an acute reference dose cannot be easily given; (2) studies from the standard toxicological database can often be used to allocate an acute reference dose and the usefulness of refinements (by requesting specific studies) should be evaluated after intake assessment; general rules on study requirements cannot be easily given; (3) more thought should be given to what safety factors apply in certain circumstances
Hexavalent and trivalent chromium in leather: What should be done?
No full textTrivalent chromium compounds are used for leather tanning, and chromium may be released during use of leather goods. In certain instances, small amounts of hexavalent chromium can be formed and released. Both trivalent and hexavalent chromium can elicit allergic skin reaction in chromium sensitised subjects, the latter being significantly more potent. Induction of sensitisation only occurs after exposure to hexavalent chromium. A minority of subjects are sensitised to chromium, and in a fraction of these subjects allergic skin reaction have been described after wearing leather shoes or, less frequently, other leather goods. The evidence that in all these cases the reaction is related to hexavalent chromium is not always strong. The content of hexavalent chromium in leather is regulated in European Union, but rate of release rather than content is relevant for allergic skin reaction. The role of trivalent chromium appear much less relevant if at all. Modern tanning procedure do not pose significant risk due to either hexavalent or trivalent chromium. Dismissing bad quality and worn-off leather goods is relevant in reducing or eliminating the skin reaction. It should also be pointed out that shoe components or substances other than chromium in leather may cause allergic/irritative skin reactions
Changing the paradigm of toxicity testing of pesticides : between science and regulation
No full text[Risk assessment and risk management of chemical exposures in agriculture]
No full textThe most important risk in agriculture derives from exposure to pesticides. Pesticide risk assessment is conducted before (pre-market) and after (post-market) the introduction in use of the substance. Evaluation of the extensive toxicological studies required for all pesticides leads to the definition of the Acceptable Operator Exposure Level (AOEL) expressed as systemic dose (mg/kg). The AOEL is compared with exposures estimated by exposure models, that are currently being revised in the European Union. Only if estimated exposure is below the AOEL the product is authorised, sometimes with compulsory use of certain personal protective equipment. These are reported in the label. Post-marketing activities include health surveillance, biological monitoring, exposure monitoring, enforcement on the use of proper and properly maintained equipment, and use of proper personal protection devices
Minisymposium : pesticide exposure and the nervous system : what evidence exists for chronic and long-term effects? Mechanisms of neurotoxicity : an overview
No full text
- …
