Electroencephalographic findings during experimental human exposure to m-xylene.

Aromatic hydrocarbon solvents, used widely in industry, cause central nervous system symptoms in exposed workers. Acute effects of m-xylene were studied in nine voluntary subjects exposed experimentally to stable or varying concentrations of m-xylene at rest or while exercising. Each subject participated in four exposure and two control sessions in a single-blind fashion.

Changes induced by short-term xylene exposure in human evoked potentials.

Nine healthy male volunteers were exposed to m-xylene for 3 h in the morning and 40 min in the afternoon with a 40-min break in between. The atmospheric m-xylene concentrations were either stable at 8.2 mumol/l (200 ppm) or they fluctuated (5.

Acute biological effects of commercial cresyl diphenyl phosphate in rats.

A commercial cresyl diphenyl phosphate preparation was analyzed to contain approximately 35% of triphenyl phosphate, 45% of cresyl diphenyl phosphates, 18% of dicresyl phenyl phosphates and 2% of tricresyl phosphates. The product was almost free of the o-cresyl isomers as revealed by the analysis of its alkaline hydrolysis products. A single intraperitoneal injection (150 or 300 mg/kg) caused an induction of microsomal cytochrome P-450 in the liver of Wistar rats with a concomitant increase in the activities of mixed function monooxygenases and proliferation of smooth endoplasmic reticulum 24 h after the treatment.

Risk factors and markers associated with proliferative retinopathy in patients with insulin-dependent diabetes.

To define risk factors and markers associated with proliferative retinopathy (PR), we compared 44 insulin-dependent diabetic patients with PR with 45 matched patients without advanced retinopathy (NR). Glycemic control assessed by HbA1 measurements from 5 yr preceding diagnosis of PR was significantly worse than in NR patients. The NR patients had more frequently been treated with multiple daily insulin injections than the PR patients.

Electron microscopy and immunohistochemistry of toxic and allergic effects of methylmethacrylate on the skin.

Prolonged exposure of rat tail skin to methylmethacrylate (MMA) caused a toxic effect on all types of epidermal cells as judged by electron microscopy. Myelin figures as a sign of degeneration of nerve processes were observed in the dermis. Immunohistochemistry and electron microscopy of MMA allergic patch tests in humans corresponded to observations seen with other allergens.

Comparison of local neurotoxicity of three white spirit formulations by percutaneous exposure of rat tail nerve.

A recently developed technique was used to compare the local neurotoxicity of three white spirit (crude oil distillates) formulations. They differed in aliphatic and aromatic hydrocarbon concentrations. Formulations I and II contained over 10% n-nonane, whereas its concentration was negligible in formulation III with 17% aromatics.

Local neurotoxicity of methylmethacrylate monomer.

A technique was devised which allowed a controlled exposure to methylmethacrylate liquid on rat tail skin. The procedure was repeated 3 h daily for 8 weeks. This caused keratolysis without ulcerations in the exposed skin and abnormal muscle responses to stimulation of the rat tail motor nerves by a skin electrode through the treated area after 4 weeks of exposure.

Impaired nerve-muscle interaction by percutaneous terphenyl exposure.

Rat tail muscle responses decreased in amplitude and showed polyphasia in intermittent (3 h daily for 4 to 8 wks) percutaneous exposure to a commercial terphenyl mixture. The gross conduction times did not change excluding demyelination as a mechanism. The exposure technique allowed an exact estimation of the absorbed dose (0.