A comparison of hyaluronan and fibronectin in the healing of tympanic membrane perforations.

Fibronectin and 1% hyaluronan, two extracellular matrix components, were applied to tympanic membrane (TM) perforations, using the laboratory rat as an animal model. The perforations occupied the upper, posterior quadrant of the TM. Saline-treated and untreated perforations of equal size served as controls.

Decreased fibronectin in rat liver altered foci and adenomas induced by N-2-fluorenylacetamide.

The disposition of fibronectin in N-2-fluorenylacetamide-induced rat liver lesions was studied by immunohistochemical staining. Male rats were fed the carcinogen for 7 weeks to induce hepatocellular altered foci and then given no chemical or phenobarbital in the diet for 24 weeks until adenomas developed. Regardless of the exposure conditions, the amount of extracellular fibronectin was unchanged in about 60% of the liver altered foci and decreased in about 40%.

Long-term carcinogenicity study in Syrian golden hamster of particulate emissions from coal- and oil-fired power plants.

Male Syrian golden hamsters were given 15 weekly intratracheal instillations with suspensions of coal fly ash or oil fly ash. Controls were instilled with saline containing gelatine (0.5 g/100 mL) or to check particle effects with suspensions of hematite (Fe2O3).

Effects of partial hepatectomy on plasma fibronectin concentrations in the rat.

Rats were subjected to 60% partial hepatectomy. In the immediate postoperative period, there was a small decline in plasma fibronectin concentrations, which was normalized already 12 h post-operatively. Metabolic labelling of fibronectin with 35S-methionine showed that the rate of incorporation of label was unchanged after partial hepatectomy.

Fibronectin concentrations in lung lavage fluid after inhalation exposure to low levels of metals.

Groups of rabbits were exposed by inhalation to chlorides of cobalt, nickel, and manganese as well as to tri- and hexavalent chromium at metal concentrations ranging from 0.4 to 3.9 mg/m3 for 1-4 months (5 days/week, 6 hr/day).