El osteoma en la mastoides, ¿un hallazgo incidental?

Osteoma in the mastoid is a rare benign osteogenic tumour that has been described in literature in only 137 cases. It usually appears in asymptomatic patients, although a few cases are described associated with clinical manifestations. We report three cases of mastoid osteoma: a pedunculated osteoma in the aditus ad antrum (associated with a cholesteatoma), a superficial osteoma of the mastoid surface and a sessile osteoma that progressed to the temporal lobe (associated with vertigo). A brief review of this rare entity is presented and a possible association between mastoid osteoma, cholesteatoma otitis and vertigo is posed.     

Temporal evolution of pneumothorax: respiratory mechanical and histopathological study

Respiratory mechanics, chest wall configuration, and lung morphometry were determined in rats before and at 30 (PTX.30) and 60 (PTX.60) min after pneumothorax induction (intrathoracic injection of 8 ml of room air; 50% collapse). Pneumothorax increased respiratory system and lung elastances and viscoelastic/inhomogeneous pressures in both groups, but respiratory system and lung resistive pressures increased only in PTX.60 group. Antero-posterior diameters at the third intercostal space and xiphoid levels, circumference at xiphoid level, and thoracic cephalo-caudal diameter increased significantly after pneumothorax induction independently of temporal evolution. In both groups lung collapse, hyperinflation, and interstitial and alveolar edema were present. Additionally, in PTX.60 group the central airways calibre diminished in relation to PTX.30. In conclusion pneumothorax yields changes in respiratory system and lung elastic and viscoelastic parameters, which are related to alveolar collapse and edema, respectively. Temporal evolution of pneumothorax also leads to changes in lung resistive pressure, probably because of airway narrowing.     

Role of Clostridium difficile infection in the relapse of ulcerative colitis

A case of nosocomial diarrhea by Clostridium difficile in an older woman with an old history of increasing stool frequency, is reported. Colonoscopy and biopsy was performed due to an incomplete response to vancomicyn, and the diagnosis of underlying ulcerative colitis was made. The incidence of Clostridium difficile infection associated with the relapse of ulcerative colitis is nearly 10%. In patients with ulcerative colitis, macroscopic pseudomembranes and the usual predisposing factors for Clostridium difficile infection, usually, are not present. It seems to exist a significant correlation between the severity of the relapse and Clostridium difficile. The specific treatment of the pseudomembranous colitis, in the majority of the cases, is sufficient for a correct control of relapse of ulcerative colitis.     

High-risk eating behavior in Mexican adolescents. Data on the student population in the Federal District

Data of the Drug and Alcohol Prevalence in Student Population of Mexico City Survey 1997 were used to achieve knowledge about the presence of risk eating behaviors, characteristic of eating disorders in the student population of Mexico city (N = 10,173). The sample was conformed by boys (47.9%) and girls (52.1%), with a mean age of 14.5 years (SD = 1.8). The identification of the differences between boys and girls, and age groups in two occurrence categories of risk eating behavior (ever and two or more times per week) were among the main objectives. An eleven items scale with three answering options about eating behavior during the last three months was used. The BMI-P distributed normally, with greater percentage of overweight, than underweight in both sexes. A greater percentage of risk eating behaviors were found among girls, excluding hard exercising and binge eating, as well as similar percentages of laxative and enema use in both sexes. The analysis held by age groups for risk eating behaviors showed significant differences in binge eating, self induced vomiting, pills and enemas use among boys, while girls showed differences in almost all of these practices, being the group of 18 and 19 years where the greater percentages were found.     

Effect of Experimental Hypertriglyceridaemia on Tissue and Serum Lipoprotein Lipase Activity

Abstract Hypertriglyceridaemia was produced in rats by the intravenous infusion of Intralipid emulsion or of very low density (d < 1.006) rabbit or human lipoproteins (VLDL). Lipoprotein lipase activity was assayed, in tissues removed at the end of infusion, on serum-activated mono- and triolein emulsions at pH 8.6. Hypertriglyceridaemia resulted in a marked decrease in epididymal adipose tissue lipoprotein lipase activity and in an increase in heart enzyme activity. These changes were evident with both mono- and triolein substrates. The effects on adipose tissue enzyme activity seemed roughly dependent on the triglyceride (TG) level and, relative to TG elevation, were most pronounced in the case of VLDL infusion. Serum lipoprotein lipase activity, measured in the absence of heparin, was considerably increased suggesting that the TG-rich material "leached" the adipose tissue enzyme into the circulation. Leaching of lipoprotein lipase from adipose tissue by Intralipid emulsion or VLDL was also demonstrated in an in vitro system devoid of heparin. Contact with the TG-poor, 1.006 < d < 1.063, lipoprotein induced only a small loss in adipose tissue lipoprotein lipase activity, either in vitro or in vivo.
Intracellular lipolytic activity toward mono- and triolein, measured in adipose tissue and heart homogenates at pH 7.2 in the absence of serum, was not significantly affected by TG elevation. Thus, the observed changes in lipoprotein lipase activity seem unrelated to the intracellular lipolytic activity.
It is suggested that the low adipose tissue lipoprotein lipase activity and the retarded TG removal observed in certain hypertriglyceridaemic conditions may be secondary to the increased supply of TG-rich lipoproteins.