A novel safety assessment strategy applied to non-selective extracts

A main challenge in food safety research is to demonstrate that processing of foodstuffs does not lead to the formation of substances for which the safety upon consumption might be questioned. This is especially so since food is a complex matrix in which the analytical detection of substances, and consequent risk assessment thereof, is difficult...

Subacute toxicity of a mixture of nine chemicals in rats: Detecting interactive effects with a fractionated two-level factorial design

The present study was intended (1) to find out whether simultaneous administration of nine chemicals at a concentration equal to the 'no-observed-adverse-effect level' (NOAEL) for each of them would result in a NOAEL for the combination and (2) to test the usefulness of fractionated factorial models to detect possible interactions between...

Toxicity of mixtures of nephrotoxicants with similar or dissimilar mode of action

The toxicity of mixtures of chemicals with the same target organ was examined in rats using nephrotoxicants with similar or dissimilar modes of action. In a 4-wk feeding study, lysinoalanine, mercuric chloride, hexachloro-1,3-butadiene and d-limonene, each affecting renal proximal tubular cells but through different modes of action, were...

Use of factorial designs in combination toxicity studies

The use of factorial designs, in which n chemicals are studied at x(n) dose levels (x treatment groups), has been put forward as one of the valuable statistical approaches for hazard assessment of chemical mixtures. Very recently a '25 study' was presented to describe interactions between the carcinogenic activity of five polycyclic aromatic...

Complex mixtures: Hazard identification and risk assessment

Regarding risk evaluation of complex mixtures, the Working Group discussed the following topics: evaluation of the mixture as a whole, fractionation of the mixture, identification of the 'top ten' chemicals, and composite standards. It was concluded that no standard methodology for hazard identification and risk assessment of complex mixtures...

Experimental designs and risk assessment in combination toxicology: Panel discussion

Advancing our knowledge on the toxicology of combined exposures to chemicals and implementation of this knowledge in guidelines for health risk assessment of such combined exposures are necessities dictated by the simple fact that humans are continuously exposed to a multitude of chemicals. A prerequisite for successful research and fruitful...

4-Week oral toxicity study of a combination of eight chemicals in rats: comparison with the toxicity of the individual compounds

In a 4-wk oral toxicity study, 4-wk-old male and female Wistar rats were exposed to a combination of arbitrarily chosen chemicals comprising sodium metabisulphite, Mirex, Loperamide, metaldehyde, di-n-octyltin dichloride, stannous chloride, lysinoalanine and potassium nitrite. The dose levels used were based on the 'no-observed-adverse-effect...

In vivo effects of toxic and detoxified endotoxin alone or in combination with muramyl dipeptide on lymphoid and non-lymphoid cells in the spleen of Meth A sarcoma-bearing mice

Chemicals/CAS: Acetylmuramyl-Alanyl-Isoglutamine, 53678-77-6; Acid Phosphatase, EC 3.1.3.2; Antigens, Surface; Antigens, Thy-1; carboxylesterase, EC 3.1.1.1; Carboxylic Ester Hydrolases, EC 3.1.1; Endotoxins; Immunoglobulins, Surface.

Respiratory tract tumours in hamsters exposed to acetaldehyde vapour alone or simultaneously to benzo(a)pyrene or diethylnitrosamine

Syrian golden hamsters were exposed to 0 or 2500-1650 ppm acetaldehyde vapour, 7 hr/day, 5 days/week for a period of 52 weeks. A proportion of the animals was given, simultaneously, either intratracheal instillations of benzo(a)pyrene (BP) or subcutaneous injections of diethylnitrosamine (DENA). All treatments were stopped after 52 weeks. The...

Tissue culture and neurotoxicology

Application of tissue culture in neurotoxicology may serve two purposes. First, they may be used to unravel the mechanism of action of neurotoxic compounds and secondly, they may be used for the screening of neurotoxic agents. Studies belonging to the first group can be subdivided into those aiming at the replication of neurotoxic processes in...

Intra arterial infusion with methotrexate in the rat

Chemicals/CAS: folinate calcium, 1492-18-8, 51057-63-7; folinic acid, 58-05-9, 68538-85-2; methotrexate, 15475-56-6, 59-05-2, 7413-34-5; Leucovorin, 58-05-9; Methotrexate, 59-05-2