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The flare reactions produced by epicutaneous tests with 68 undiluted allergenic pollen extracts were measured in 550 allergic patients. Skin test reactions greater than or equal to 2, greater than or equal to 5, greater than or equal to 10, greater than or equal to 20, and greater than or equal to 30 mm in diameter, respectively, were detected in approximately 67%, 22%, 10%, 3%, and 1% of the 34,700 skin tests. With the Kolmogorov-Smirnov difference test, the cumulative frequency of reaction diameters and loge-transformed diameters of all reactions and reactions to individual allergenic extracts differed significantly (p less than or equal to 0.01) from a normal distribution. The ability to identify specific differences between reactions to closely related pollen extracts was evaluated. Specific reactions could be reliably identified with greater than or equal to 10 mm diameter flares. This arbitrary conservative threshold was used to estimate the relative prevalence of positive reactions to each allergenic extract. Seven allergenic extracts elicited the first quartile of all positive reactions. Thirteen, 18, and 30 allergenic extracts, respectively, were needed to elicit the second, third, and fourth quartiles of all positive reactions. Reactions to amphiphilous, as well as anemophilous, pollens were detected. Skin test reactions to grasses were more prevalent than reactions to weeds and trees. The most informative allergenic extracts for the detection of patients who exhibited a positive reaction to any extract were from red fescue-grass pollens, mesquite, short ragweed, red clover, and timothy-grass pollens.

To evaluate the myocardial protection afforded by multiple-dose versus single-dose administration of potassium cardioplegic solution, we studied 24 isolated feline hearts before, during, and after 1 hour of ischemic arrest. Intramyocardial gas tensions, ventricular function, histologic preservation, and postischemic myocardial edema were compared in hearts maintained at 27 degrees C during the ischemic period. Equal groups of hearts received no infusion of cardioplegic solution, a single dose of potassium solution at the onset of ischemia, or multiple infusions of the cardioplegic solution throughout the arrest period. During ischemia, single-dose cardioplegic administration resulted in less accumulation of myocardial carbon dioxide (Pmco2) than did hypothermia alone, reflecting a reduction in metabolic activity during ischemia. The fact that multiple-dose cardioplegia further reduced Pmco2 accumulation suggests an intermittent washout of metabolic end products. During reperfusion, hearts protected by multidose cardioplegia demonstrated superior preservation of ventricular performance compared to hearts protected by single-dose cardioplegia or hypothermia alone. In addition, multiple infusions of the cardioplegic solution resulted in optimal structural preservation in both light and electron microscope studies.