bromochloroacetic-acid and Weight-Gain

12-O-Tetradecanoylphorbol-13-acetate (TPA) was applied to the back skin of v-Ha-ras (TG-AC) female transgenic mice at a dose of 2.5 microg/200 microl twice a week for 9 weeks. The back skin was then exposed to blue light (wavelength, 470 nm; irradiance, 5.7 mW/cm2) for 1 h daily for 9 weeks. The mice to which TPA was applied developed skin tumors at 6 weeks after the start of application. The tumor incidence rates at 6, 7, 8 and 9 weeks after the start of application were 70%, 80%, 100% and 100%, respectively, and the numbers of tumors 1 mm or more in diameter were 1, 5, 10 and 19, respectively. In the mice that were exposed to blue light after TPA application, the tumor incidence rates were 10%, 40%, 60% and 80%, respectively, and the numbers of tumors 1 mm or more in diameter were 0, 2, 5 and 9, respectively. Histopathological examination of the skin revealed that TPA application induced diffuse hyperplasia, exaggerated keratinization, and papillomas in all 10 mice. A localized form of epidermal hyperplasia was also observed in 4 mice. The incidence rate of papillomas in the mice that were exposed to blue light after TPA application was lower and the degree of exaggerated keratinization was greater. Exaggerated keratinization was considered to represent a regressive change following exposure. These findings suggest that exposure to blue light may be a promising new approach in the treatment of skin tumors.

Topics: Animals; Epidermis; Female; Genes, ras; Hyperplasia; Keratins; Mice; Mice, Transgenic; Oncogene Protein p21(ras); Papilloma; Phototherapy; Precancerous Conditions; Recombinant Fusion Proteins; Skin Diseases; Skin Neoplasms; Tetradecanoylphorbol Acetate; Weight Gain

Twelve newborn Holstein bull calves were used to evaluate the effects of dietary abrasiveness, determined by a new method, on ruminal development. Calves were blocked by age and body weight and were assigned to one of three different diets. Each diet had the same ingredients but different particle sizes, which resulted in different abrasive values. No differences were detected in molar percentages of volatile fatty acids in ruminal fluid or in plasma concentrations of urea, glucose, or beta-hydroxybutyrate. The pH of ruminal fluid was lower for calves fed the fine and intermediate diets than for those fed the coarse diet. Digesta-free weights of the stomach and stomach compartments were similar among calves fed the three diets, except that omasum weights were heavier for calves fed the fine diet. Length of the ruminal papillae increased as the abrasive value of the diet decreased. Measurements of ruminal tissue layers from the ventral floor of the cranial sac were not different among diets, but the keratin portion represented more of the epithelial layer for calves fed the diet with the lowest abrasive value, thus decreasing the percentage of metabolically active tissue for those calves.

Topics: 3-Hydroxybutyric Acid; Animal Feed; Animals; Cattle; Chemical Phenomena; Chemistry, Physical; Diet; Eating; Fatty Acids, Volatile; Hydrogen-Ion Concentration; Hydroxybutyrates; Keratins; Particle Size; Rumen; Weight Gain