Developmental toxicity of combined ethylbenzene and methylethylketone administered by inhalation to rats.

Pregnant Sprague-Dawley rats were exposed to ethylbenzene (EB; 0, 250, or 1000 ppm) and methylethylketone (MEK; 0, 1000, or 3000 ppm), alone and in combination, by inhalation, for 6h/day, during days 6-20 of gestation. Maternal toxicity, evidenced by decreased in body weight gain and food consumption, tended to be greater after simultaneous exposures to the high concentrations of 1000 ppm EB and 3000 ppm MEK, when compared to the treatments with individual compounds. No significant increase in embryo/fetal lethality or incidence of malformations and variations was observed in any of the treatment groups. Fetal body weight was significantly reduced after individual treatment with 1000 ppm EB or 3000 ppm MEK, and in the combined groups. There was no evidence of interaction between EB and MEK in causing developmental toxicity.

Neutrophil functions in lead-exposed workers.

Neutrophil functions were studied in 38 lead-exposed workers compared to 34 controls. Both groups were matched according to age, sex, drinking and smoking habits, ethnic origin and drug intake. Blood lead levels were found to be seven times higher in exposed workers than in controls. Phagocytosis assayed by chemiluminescence was found to be slightly but not significantly altered in exposed workers. In contrast, chemotaxis using the agarose technique was significantly depressed. These results are in agreement with previous in-vitro findings. A further assessment of clinical consequences is warranted.

[Immunological quantity determinations of hPL and total oestrogens during the course of pregnancy (author's transl)]. / Dosages immunoenzymologiques de l'hPL et des oestrogènes totaux au cours de la grossesse.

The quantity determination of hPL and of total plasma oestrogens, by means of immuno-enzymology in the heterogenic phase, allows a satisfactory pregnancy. The methods of quantity determination are presented and studied; the criteria for the quality of these methods, and the values found during the course of normal pregnancy, can allow them to be used in many laboratories.

[Comparison of radial immunodiffusion and laser nephelometry for the determination of pregnancy specific beta 1-SP1-glycoprotein in plasma]. / Comparison de l'immunodiffusion radiale et de la néphélométrie laster pour le dosage de la beta 1-SP1-glycoprotéine plasmatique.

Concentrations of pregnancy-specific beta 1-glycoprotein were assayed in 137 plasmas by radial immunodiffusion and laser nephelometry. The two methods were evaluated in parallel. A good correlation factor was founded for SP1 values above 60 mg/l. Although the sensitivity of both methods at low concentrations remained unsatisfactory, that of laser nephelometry was superior and therefore to be preferred.

Immunological protection against ajmaline toxicity.

In search for an effective treatment of human poisonings with ajmaline, a potent antiarrhythmic drug, the use of specific antibodies as neutralizing agents was explored in a preliminary animal model. For this purpose, New Zealand white rabbits were immunized with the antigen obtained after coupling the 17-hemisuccinate ester of ajmaline-21-acetate to bovine serum albumin, whereas other rabbits were immunized with the protein carrier only. While seven control rabbits receiving 0.625 mg/kg/min. ajmaline intravenously until death, died within 54.8 +/- 5.2 min. death was delayed until 137.7 +/- 15.5 min in seven ajmaline bovine serum albumin-immunized rabbits (p less than 0.001). Three bovine serum albumin-immunized rabbits behaved as controls. These results provide evidence that an immunological protection against ajmaline toxicity can be obtained in laboratory animals.

Evaluation of active specific immunization against paraquat toxicity in rats.

Four groups of Wistar rats were immunized against a BSA-paraquat derivative antigen, when lethally poisoned with paraquat dichloride via intraperitoneal route. No significant correlation in survival rate was observed between immunized (5/45) and control (0/26) rats, but a significant correlation (p less than 0.05) in the mean survival time was noted in immunized rats as compared to controls (9.1 +/- 16.8 days and 2.0 +/- 0.8 days versus 2.1 +/- 2.4 days and 1.0 +/- 0.1 days respectively).

Increased plasma paraquat levels in intoxicated mice following antiparaquat F(ab')2 treatment.

Death most often results from human acute poisonings due to paraquat, a widely used herbicide. It causes a quick and insidious accumulation in lungs. It was proposed to study the effects of the administration of antiparaquat F(ab')2 fragments in mice intoxicated with paraquat. Antisera against a paraquat acid derivative coupled to bovine serum albumin were prepared in rabbits, then purified using immunoaffinity chromatography columns and fragmented by pepsin. Antiparaquat F(ab')2 antibodies obtained were preventively injected to mice. After intravenous paraquat injection of 8 mg/kg, plasma paraquat levels were measured from 0.25 to 48 hours. Plasma from antiparaquat F(ab')2 pretreated mice as compared with non-specific immunoglobulin pretreated control mice showed a significant increase (p less than 0.001) of the paraquat concentrations from the 4th (1.17 +/- 0.06 versus 0.20 +/- 0.01 microgram/ml) to the 48th hour (0.47 +/- 0.08 versus 0.02 +/- 0.01 microgram/ml). Although pulmonary paraquat concentrations presented no modification, it could be considered that these preliminary results would have to be studied thoroughly with a view to finding an efficient treatment in human acute poisoning with paraquat.