Pulmonary toxicity induced by intratracheal instillation of coarse and fine particles of cerium dioxide in male rats.

In order to examine the short-, medium- and long-term effects of cerium dioxide particles of different sizes on the lung, 10-wk-old male Wistar rats were administered a physiological saline solution with a suspension of coarse or fine particles of cerium dioxide at 34 mg/kg body weight by a single intratracheal instillation. Lungs were examined with cellular and biochemical analyses of the bronchoalveolar lavage (BAL) fluid and histopathology on different days after the instillation. Geometric mean and geometric standard deviation of the diameter were 3.

Dissolution of functional materials and rare earth oxides into pseudo alveolar fluid.

The dissolution rates of rare earth oxides and two types of rare earth containing functional materials into water, saline solution, and Gamble's fluid were measured in order to evaluate the biological effects of rare earth-containing functional materials. The tested materials were yttrium, lanthanum, cerium and neodymium oxides, and neodymium-boron-iron magnet alloy (NdBFe) and lanthanum-mish-metal-nickel-cobalt (LmNiCo) hydrogen-containing alloy. The dissolution rates of the rare earth oxides were very low, resulting in concentrations of rare earth elements in the test solutions of the order of ppb.

Effects of surface characteristics of potassium titanate whisker samples on acute lung injury induced by a single intratracheal administration in rats.

We compared in vivo biological effects, focusing on lung inflammatory responses after a single intratracheal administration of two types of well-characterized whiskers: potassium octatitanate and potassium hexatitanate, which have similar fiber sizes and chemical compositions, except their surface morphology. The geometrical mean of length (microm), width (microm), and geometric standard deviation (GSD) are: K(2)Ti(8)O(17) (PT1), 6.0[2.