[The document of chemical risk assessment: experiences in small companies]. / Il documento di valutazione del rischio chimico: esperienze nelle piccole imprese.

Were examined 60 documents of chemical risk assessment of companies from 19 municipalities in the provinces of Siena and Grosseto. The review of evaluations was conducted initially by checking the internal coherence of the documents. What emerged was subsequently analyzed together with the staff who performed the inspection. Although in 12 companies has been declared the presence of carcinogens, in only 5 the evaluation of exposure have been done using measures, others have used models or other techniques. Overall assessment showed that only 8 out of 60 (13.3%) were wrote correctly.

Inhibitor of antagonist binding to the muscarinic receptor is elevated in Alzheimer's brain.

The 100,000 x g supernatant fraction of human brain contains endogenous inhibitors of antagonist binding to the muscarinic receptor. Significantly greater inhibition was observed with Alzheimer's than non-demented control supernatant fractions. Low molecular weight inhibitor was separated from larger inhibitor species by membrane dialysis (3,500 dalton cut-off). The activity of low molecular weight inhibitor was greatly increased by sulfhydryl reducing agents. While the low molecular weight inhibitor was stable to heat, acid and base for short time periods (< 20 min), it was inactivated by acid hydrolysis (50% loss after 16 h, 100% loss after 96 h). The low molecular weight inhibitor activity is elevated approximately three-fold in Alzheimer's brain. The low molecular weight inhibitor from Alzheimer's brain was found to be a non-competitive inhibitor. This is the first report of endogenous inhibitors in human brain of ligand binding to the muscarinic receptor and of increased inhibitor activity in Alzheimer's disease.