Neurotoxicity of 1-methoxycycloheptatriene--a Purkinje cell toxicant.

The toxicity of 1-methoxycycloheptatriene (1-MCHT), a sensory irritant, has been investigated in beagles. It was found to produce gross inco-ordination of the limbs at intravenous doses greater than 10 mg kg-1. The main histological abnormalities were in the cerebellum and consisted of Purkinje cell death and subsequent reactive gliosis.

The repeated dose toxicity of a zinc oxide/hexachloroethane smoke.

Mice, rats and guinea pigs were exposed to the smoke produced by ignition of a zinc oxide/hexachloroethane pyrotechnic composition, 1 h/day, 5 days/week, at three different dose levels, together with controls. The animals received 100 exposures except for the high dose guinea pigs, which underwent 15 exposures, because of high death rate during the first few days of exposure. The test material had very little effect on weight gain, but there was a high rate of early deaths in the top dose of mice.

Inhalation toxicity of a smoke containing Solvent Yellow 33, Disperse Red 9 and Solvent Green 3 in laboratory animals.

The repeated-dose inhalation toxicity of a smoke containing a mixture of three dyes was tested in female mice, rats and guinea pigs. The green component dye (Solvent Green 3) was retained in the lungs. Particularly in the rats marked collections of alveolar macrophages were found.

Pathological changes produced by exposure of rabbits and rats to smokes from mixtures of hexachloroethane and zinc oxide.

Rabbits and rats were exposed to single doses of hexachloroethane zinc smoke and observed for up to 14 days. Changes in the respiratory tract included acute inflammation and in some cases necrosis of the laryngeal and tracheal mucosa. Pulmonary oedema and pneumonitis were observed in decedent animals.

A repeated dose study of the toxicity of technical grade dibenz-(b.f.)-1,4 oxazepine in mice and hamsters.

The repeated dose inhalation toxicology of technical grade dibenz-(b.f.)-1,4 oxazepine (CR) was studied in mice and hamsters.

A repeated dose study of the toxicity of inhaled 2-chlorobenzylidene malononitrile (CS) aerosol in three species of laboratory animal.

The repeated dose inhalation toxicity of 2-chlorobenzylidene maloninitrile (CS) was investigated in male mice, rats, and guinea-pigs. Exposure was 1 h X day-1 for 120 days surviving animals being killed approximately 1 year after the start of exposure. Excess mortality was noted in the high dose groups of all three species but at exposure concentrations below 30 micrograms X 1(-1) mortality varied little between the control and test groups.

A repeated dose study of the toxicity of CR applied to the skin of mice.

Dibenz (b,f)-1-4 oxazepine (CR) was applied to the skin of C3H and Porton-strain mice, daily for 12 weeks. After a further 80 weeks the animals were sacrificed and examined grossly and histologically. The results were compared with appropriate solvent and untreated controls.

Cutaneous histamine-releasing activity of dimethylsulphoxide (DMSO) in guinea pigs.

Dimethylsulphoxide (DMSO) induced swelling in guinea pig ears was found to be abolished by H1- and H2-receptor blocking agents. On histological examination of the ears some degranulation of mast cells was seen. It was concluded that the swelling was mediated by histamine release.

Ultrastructure of rat lungs following exposure to aerosols of dibenzoxazepine (CR).

Three groups of 18 animals were exposed respectively to the following large doses of dibenz (b.f)-1:4 oxazepine (CR) aerosols, 78,200,140,900 and 161,300 mg/min/m3. Animals were killed at intervals from 15 min to 2 days, and the lungs examined macroscopically, by electron microscopy and conventional histology.