Exposure to combinations of substances: A system for assessing health risks

Combined exposures may be categorised as specified combinations or mixtures of substances, depending on composition and exposure scenario. The major characteristic of a specified combination is known composition and that of a mixture simultaneous exposure. A framework was developed as a guide for safety evaluation of combined exposures. This...

Summary of the report 'Toxicology-Based Recommended Exposure Limits'

Toxicologische advieswaarden voor blootstelling aan stoffen [Toxicology-based recommended exposure limits]

Migration of human antigen-presenting cells in a human skin graft onto nude mice model after contact sensitization

Fluorescent contact chemical allergens provoke sensitization after application on both syngeneic and allogeneic skin grafts in mice. We attempted to determine whether the functional activity in a contact sensitization response of human skin graft was affected at the level of antigen uptake and migration. After xenogeneic skin transplantation, we...

Te veel onbekend over arbeidsmarktpositie chronisch zieken

Sinds de invoering in augustus 1993 van een nieuw arbeidsongeschiktheidscriterium is sprake van een toename van het aantal chronisch zieken dat geschikt geacht wordt om werk te verrichten. Door de strenge selectie op gezondheid bij personeelswerving, lijken hun kansen op de arbeidsmarkt echter beperkt. Om de werkloosheid onder deze groep tegen...

In vivo cytokine profiles in allergic and irritant contact dermatitis

Local cytokine profiles in skin biopsies from allergic and irritant patch test reactions were determined by in vivo immunohistochemistry to differentiate between these 2 clinically identical afflictions especially at the time of final reading in diagnostic patch testing. Biopsies were taken from established allergic persons after specific...

Reduction of thyroxine uptake into cerebrospinal fluid and rat brain by hexachlorobenzene and pentachlorophenol

In the present study the effects of hexachlorobenzene (HCB) and the metabolite pentachlorophenol (PCP) were investigated with respect to uptake of thyroxine (T4) into cerebrospinal fluid (CSF) and brain structures of rats. [125I]T4 was taken up into CSF of control rats by a relatively slow process, reaching a steady state after about 3 h. Both...

Hexachlorobenzene and its metabolites pentachlorophenol and tetrachlorohydroquinone: Interacion with thyroxine binding sites of rat thyroid hormone carriers ex vivo and in vitro

Previous results have indicated that hexachlorobenzene (HCB)-induced hypothyroidism may be caused by its main metabolite pentachlorophenol (PCP), and by tetrachlorohydroquinone (TCHQ), rather than by the parent compound. In the present experiments it was investigated whether hormone displacement from serum carriers could be a factor in the...

Interactions of halogenated industrial chemicals with transthyretin and effects on thyroid hormone levels in vivo

Previous results in experimental systems have suggested that hydroxylated PCBs may decrease thyroid hormone levels through associative interaction with transthyretin. In the present paper it was investigated whether this property was also shared by various industrial chemicals, mainly pesticides. In total, 65 compounds from 12 chemical groups...

Internationale workshop 'Health surveillance of individual workers exposed to chemical agents'; Coronel Laboratorium, Universiteit van Amserdam, 29-31 oktober 1986

Wetenschappelijke dag t.g.v. het afscheid van Prof. Zielhuis, 28 november 1986.

Effect of variable versus fixed exposure levels on the toxicity of acetaldehyde in rats

The effects of exposure pattern on the toxicity of acetaldehyde vapour were investigated in 4-week inhalation studies. Male rats were exposed to 500 or 150 and 110 ppm for 6 h per day/5 days per week. One group of animals was exposed without interruption, the exposure of a second group was interrupted for 1.5 h between the first and second 3-h...