Knowledge of the time course of penile erection is very important to understanding erection physiology. The changes in the intracavernosal pressure (ICP) and the different phases of an erection are pivotal to the ability to produce and maintain a rigid penile erection. This study investigated an objective and low-invasiveness method for identifying different erection phases based on an innovative ICP analysis technique. Blood infuses into the corpora cavernosa and causes the ICP to increase. The ICP usually exhibits tiny oscillations at the frequency of the heartbeat when it increases from diastole to systole. The characteristic oscillation amplitudes corresponding to the period when the full and rigid erection phases begin can be extracted by power spectral density analysis. The reliability and accuracy of the proposed method was verified by the Bland-Altman graphs indicating a good agreement with the existing method that compares the ICP with the arterial pressure. Moreover, all of the intraclass correlation coefficient values were close to 1.00, with the lower limit of the 95% confidence interval exceeding 0.75. The described novel objective and low-invasiveness method can therefore be used for identifying the full and rigid erection phases of the penis in urological investigations during different erection phases.

We analyzed cytokine expression in recipient spleens and cardiac allografts placed in mice that were unable to synthesize interleukin (IL)-4 due to disruption of the IL-4 gene (IL-4 -/-) and in wild-type (IL-4 +/+) mice. Polyclonal BL-4P and monoclonal 11B11, 1D11, and 24G2 anti-IL-4 antibodies were used to detect cell-surface and cytoplasmic antigens in sections of frozen tissue. All of the antibodies were found to react with non-IL-4 determinants associated with graft-infiltrating cells, and BL-4P, 1D11, and 24G2 bound to cells and connective tissue in the spleens of IL-4 -/- mice. The IL-4-producing cell line, X63Ag8-653 (X63), was used as a positive control for IL-4 staining and to test the ability of recombinant IL-4 to block the binding of antibodies to IL-4.