RESUMEN
A factorially designed experiment was chosen to form alloys of a gold-palladium-silver-copper quaternary system. A total of 81 alloys for three levels of concentration of each of the four elements were made and tested for the degree of tarnish in in vivo and in vitro environments. The following conclusions may be drawn: 1. In both the in vitro and in vivo experiments, increasing the gold levels of concentration within an alloy decreased the degree of tarnish. 2. In both the in vitro and in vivo experiments, increasing the palladium levels of concentration within an alloy decreased the degree of tarnish with an influence greater than that produced by the gold content. 3. In the in vitro environment of 2% sodium sulfide solution, the degree of tarnish increased as the levels of concentration of silver to copper were increased. 4. In both the in vitro and in vivo experiments, the effect of the interaction of the four elements on the degree of tarnish and corrosion is directly related not only to the concentration of each element within the alloy, but also to their ratios.
Asunto(s)
Aleaciones Dentales , Fenómenos Químicos , Química Física , Cobre/análisis , Corrosión , Aleaciones Dentales/análisis , Aleaciones de Oro/análisis , Humanos , Técnicas In Vitro , Boca/fisiología , Paladio/análisis , Plata/análisis , Factores de TiempoRESUMEN
The feeding of bovine milk to five highly allergic pediatric patients with bilateral family histories of atopy led to transient malabsorption of glucose and fat as well as systemic autonomic functional changes which may be attributable to pharmacologic actions of histamine and/or acetylcholine. It is hypothesized that during allergic reactions endogenously released smooth muscle stimulating neuromediators could provide rapid propulsion of nutrients through the absorbing portion of the gut, leading to suboptimal absorption, and that bovine milk inducible malabsorption in the atopic patients has an immuno-pharmacologic basis in its pathogenesis.
Asunto(s)
Hipersensibilidad a los Alimentos/complicaciones , Síndromes de Malabsorción/etiología , Proteínas de la Leche/efectos adversos , Adolescente , Animales , Permeabilidad Capilar , Glándulas Exocrinas/metabolismo , Heces/análisis , Femenino , Motilidad Gastrointestinal , Glucosa/metabolismo , Histamina/fisiología , Humanos , Lactante , Absorción Intestinal , Lípidos/análisis , Síndromes de Malabsorción/inducido químicamente , Síndromes de Malabsorción/complicaciones , Síndromes de Malabsorción/fisiopatología , Masculino , Leche/efectos adversos , Moco/metabolismo , Sistema Nervioso Parasimpático/fisiopatología , Rinitis Alérgica Estacional/complicacionesRESUMEN
Seven allergic patients with bovine milk or milk protein-inducible transient intestinal malabsorption exhibited radiologic signs of rapid transit of ingested barium through the proximal small intestine hours following oral challenge with bovine milk or milk protein solution. Control studies in the same patients without prior milk challenge revealed significantly more leisurely progress of contrast medium in the proximal small bowel. The possible pathogenetic role of such hasty transit through the functionally most effective portion of the digestive tract in patients with malabsorption points up the physiologic importance of roentgen examination of motility patterns in this particular segment of small bowel.