AIMTo determine if there are different penile hemodynamic patterns between sildenafil non-responders and responders by using color Doppler ultrasonography.

METHODSA total of 69 erectile dysfunction (ED) patients aged 22-79 years were enrolled into the present study. Thirty-eight (55.1%) men with ED who did not respond to four attempts of treatment with 100 mg sildenafil after re-education were classified as sildenafil non-responders. A combination of three vasodilator drugs, 1.25 mg papaverine, 0.4 mg phentolamine and 5 mg prostaglandin E1, was given by intracavernous injection before penile Doppler ultrasonography was carried out. The erectile response to intracavernous injection and vascular parameters including peak systolic velocity (PSV), resistance index (RI), end diastolic velocity (EDV) and cavernosa artery diameter (CD) were measured and the results between sildenafil non-responders and responders were compared.

RESULTSNo statistical difference in vascular parameters measured by Doppler ultrasonography studies between non-responders and responders was noted. Sildenafil non-responders had a poorer penile rigidity response to intracavernous injection than responders (P < 0.05). Among patients with adequate PSV (>or=30 cm/s) and abnormal EDV (> 5 cm/s), individuals in the non-responder group had fewer positive responses to intracavernous vasodilator injection than in the responder group (35.3% vs. 72.2%, P < 0.05). Advanced age and comorbidity with diabetes mellitus were significantly associated with sildenafil non-response (P < 0.05).

CONCLUSIONSildenafil non-responders were characterized by a poorer penile rigidity response to intracavernous injection and had an associated impaired veno-occlusive mechanism. Advanced age and comorbidity with diabetes mellitus were two common factors associated with non-response.

Adult ; Aged ; Alprostadil ; therapeutic use ; Erectile Dysfunction ; diagnostic imaging ; drug therapy ; Humans ; Male ; Middle Aged ; Papaverine ; therapeutic use ; Phentolamine ; therapeutic use ; Piperazines ; therapeutic use ; Purines ; therapeutic use ; Sildenafil Citrate ; Sulfones ; therapeutic use ; Ultrasonography, Doppler, Color ; Vasodilator Agents ; therapeutic use

The aim of this study was to determine the correlation of ultrasonographic estimates of testicular volume with true testicular volume and to compare the accuracy and precision of the three most commonly utilized formulas. A total of 15 patients underwent high-resolution ultrasonography (US) analysis for testicular volume before orchiectomy. Testicular volume was calculated using three common formulas: (1) length (L) x width (W) x height (H) x 0.52; (2) the empirical formula of Lambert: L x W x H x 0.71; and (3) L x W2 x 0.52. The actual volume of each removed testis was estimated directly by a water displacement method. Thus, four volume measurements were obtained for each of the 30 testes. The obtained data were analyzed by paired t-test and linear regression analysis. All three US formula measurements significantly underestimated the true testicular volume. The largest mean biases were observed with US formula 1, which underestimated the true volume by 3.3 mL (31%). US formula 2 had a smaller mean difference from the true volume, with an underestimation of only 0.6 mL (6%). Regression analysis showed that formulas 1 and 2 had better R2 values than formula 3. However, all three US formulas displayed a strong linear relationship with the true volume (R2= 0.872-0.977; P < 0.001). Among the commonly used US formulas, the empirical formula of Lambert (L x W x H x 0.71) provided better accuracy than the other two formulas evaluated, and better precision than formula 3. Therefore, the formula of Lambert is the optimal choice in clinical practice.
Aged ; Aged, 80 and over ; Humans ; Male ; Middle Aged ; Organ Size ; Reproducibility of Results ; Testis ; anatomy & histology ; diagnostic imaging ; Ultrasonography ; methods

A liquid chromatography equipped with tandem mass spectrometric method using multistage flow rates was developed for the determination of donepezil in human plasma to support a randomized, crossover bioequivalence (BE) study in which healthy volunteers each received a single oral dose of the reference and test formulations of 10 mg donepezil hydrochloride. This integrated liquid chromatography with tandem mass spectrometry (LC-MS/MS) system with electrospray ionization and a deuterium-labeled internal standard (IS) were employed for the positive multiple-reaction-monitoring (MRM) analyses. The baseline separation using a high-resolution monolithic column under gradient and flexible flowrate conditions between donepezil and multiple interfering peaks from the extracted quality control, calibration standard and study plasma samples following simple protein precipitation extraction procedures was accomplished within 1.5 minutes. The ultrafast monolithic column performance in terms of chromatographic separation efficiency, peak asymmetry and resolution and retention time reproducibility was found to be sustainable.The linear dynamic range was detected over a concentration range of 0.2–50 ng/mL. The intra- and inter-day assay accuracy and precision were within 15% for the analyte in individual biological fluids. A positive correlation coefficient (r) greater than 0.995 for donepezil concentrations in study plasma samplers measured by the proposed and the other validated LC-MS/MS methods in support of a bioequivalence study was observed.