The use of large-scale cDNA analysis to profile differential gene expression in KYSE 410 human esophageal cancer cells after irradiation.

Atlas Human cDNA Expression Array, which includes 588 genes divided into functional classes, was used to study gene expression profiles in KYSE 410 human esophageal cancer cells irradiated in doses of 6 and 18 Gy. Considerable changes in the expression of a number of genes was found, including down-regulation of 3 cell cycle regulators and up-regulation of an apoptosis-related gene. Comparison of the expression profiles and identification of genes were performed with Atlas Vision 3.0 software.

Age-specific patterns of diagnosis of acute otitis media.

A retrospective review of clinical experience with the diagnosis of acute otitis media (AOM) in a large pediatric population (age, 0-12 years old) reveals two age-specific patterns of diagnosis: one in preschool children and one in schoolage children. In the population as a whole, AOM is diagnosed most frequently in the first 5 years of life; rates of diagnosis vary with gender (male: female ratio = 1.10) and season (fall/winter peak). In a linear regression model, age, gender, season, and interactions among these account for 52 percent of the variability in diagnostic rates. In children less than 5 years of age, rates of diagnosis vary strikingly with gender and season; the regression model accounts for 55 percent of observed variability in diagnostic rates. In schoolage children (5-11 years old), however, males and females are equally likely to be diagnosed to have AOM, and seasonal variability is blunted; among these children, the regression model predicts only 22 percent of diagnostic rate variability. These findings buttress existing knowledge of the epidemiology of AOM and have important implications for clinical practice, health planning, and pediatric research.

High-altitude retinopathy.

Thirty-nine healthy subjects were examined before and after a stay at 5,360 m by ophthalmoscopy and by retinal photography. Twenty of them were also tested for visual acuity, scotomata, and capillary leakage. Vascular engorgement and tortuosity and disc hyperemia were seen in all subjects at altitude and are a "normal" response to hypoxia. Twenty-two (56%) of the subjects had retinal hemorrhages and one showed "cotton-wool spots". These changes are abnormal reactions and are considered high-altitude retinopathy. After maximal exertion on a cycle ergometer, fresh hemorrhages were observed in seven of 34 subjects. The incidence of hemorrhage associated with exercise was significantly greater than predicted. Fluorescein leakage was noted after exercise in eight of 20 persons tested and was associated with exercise-induced hemorrhages. Two persons developed premacular hemorrhages.

Effect of altitude exposure on platelets.

Since decompression from depth is known to produce a fall in platelet count, the effect of altitude decompression and high-altitude exposure on platelets was investigated. Sixteen subjects decompressed without hypoxia to 20,000 ft simulated altitude for two hours showed a significant (P less than 0.01) drop in circulating platelet count of approximately 10% for three days following decompression. Four of five subjects similarly exposed had a shortened autologous platelet survival compared to that prior to exposure. Subjects exposed to 9,800 ft and then 17,600 ft in a mountain environment showed a significant mean decrease in platelet count on day 2 of 7% and 25% respectively, which had returned to control by day 5. Nonhypoxic and hypoxic decompressed rabbits which received homologous chromium-51-labeled platelets had an increase in lung radioactivity compared with sea-level controls. It is postulated that altitude decompression produces platelet reductions similar to these seen after decompression from depth, and that platelets sequester in the pulmonary vascular bed.