Gades, Naomi M.

Abstract In collaboration with the American College of Veterinary Pathologists

Percutaneous transendocardial injections of therapeutic agents into the myocardium may not always be effective. We used an animal model for assessing the efficacy of the injections using linoleic acid as a testing agent. Efficacious delivery into the myocardium of a beating heart was indicated by rapidly developed local myocardial necrosis and wall motion abnormalities using echocardiography. We employed this experimental model to test our innovative technology, an acoustically active injection catheter. The Doppler ultrasound‐guided acoustically active injection catheter effectively delivers the substance to the myocardium but needs further technical improvements to minimize an unwanted systemic distribution of the agent.

Abstract Background and aims Endoscopic resections are associated with bleeding and perforation and may be managed with through-the-scope (TTS) clips, over-the-scope clips and endoscopic suturing. The aim of this preclinical study was to compare technical success of closure using a novel TTS tissue helix tack and suture device (X-Tack) to TTS clips in a porcine model. Materials and methods Four subjects underwent 40 mucosal resections, diameter range 25–50 mm, in the stomach (n = 24) and colon (n = 16). Closures were randomized to X-Tack (n = 24) or clip (n = 16). Animals underwent weekly endoscopic follow-up for 4 weeks. Results Technical closure with X-Tack was successful in 24 of 24 (100 %) cases and with clips in 13 of 16 cases (81.3 %) (P = 0.0001). One colonic perforation occurred and was successfully managed using X-Tack. The rate of healing was not statistically different between the groups, and all sites healed at 4 weeks including the perforation and were confirmed by histology. Conclusions Compared to TTS clip, X-Tack is superior for effecting large mucosal defect closure, including durable sealing of full-thickness perforation. There was no difference in rate of healing between devices.

214 Background: In our preliminary in vitro studies, we have demonstrated evidence of enhanced apoptosis and inhibition of cellular proliferation in both hormone sensitive and castrate resistant prostate cancer (PCa) cell lines using a combination of an antiandrogen (Bicalutamide) and a selective estrogen receptor modulator (Raloxifene). The aim of this study was to study the effect of the administration of these two drugs in in vivo models of castrate resistant PCa. Methods: In vivo model consisted on NCr Nude: Mice bearing s.c. human prostate (PC3 cell line) xenografts. Based on the treatment received, mice were divided into 5 groups as follows: Group 1: No drugs (control); Group 2: Bicalutamide 50mg; Group 3: Raloxifene 60 mg; Group 4: Combined administration of Bicalutamide 50 mg and Raloxifene 60 mg; Group 5 Combined administration of Bicalutamide 150 mg and Raloxifene 120 mg. A total of 10 mice where included in each group. All drugs dosages were converted to their equivalent in the mice. Drugs were administered by gavage technique to the mice once per day for a total of 14 days. Results: As expected, Bicalutamide administered alone causes minimal inhibition without reaching statistical significance (Group 2: 0.34 g Vs Group 1: 0.40 g; p=0.073). Although Raloxifene causes some marked growth inhibition, its effect is not statistically significant (Group 3: 0.31 Vs Group 1: 0.40 g; p=0.062). Bicalutamide and Raloxifene, when administered in combination, induced prominent growth inhibition in PC3 tumors when compared to the control group (Group 4: 0.26 g Vs Group 1: 0.40 g; p=0.038). Growth inhibition is significantly more evident when the drugs dosages are increased (Group 5: 0.17 g Vs Group 1: 0.40 g; p=0.024). Conclusions: The simultaneous administration of Bicalutamide and Raloxifene appears to have a synergistic effect on tumor growth inhibition in PC3 xenografts. The pathway(s) responsible for this observation may be independent of the androgen receptor as PC3 cells are AR negative and still affected by the combination over the drugs administered alone. Research is warranted to identify these potential pathways.

Pharmacokinetics of drugs may differ between small and large mammals (including humans); therefore, drug testing in animal models must be carefully designed. Sprague–Dawley rats were used in cardiac experiments, during which the lopinavir concentration in serum had to match human therapeutic levels (4–10 μg/mL). Lopinavir was administered as a co-formulated drug of lopinavir and ritonavir. It was found that after a single administration of a standard human peroral dose (lopinavir 13.3 mg/kg of body weight), the serum concentration of lopinavir was only one-tenth of the target level. It remained below the minimum target level even after 10-fold the standard dose was administered. After initial pilot tests, a dose escalation study was conducted with oral doses 10- and 15-fold the standard clinical dose of lopinavir (i.e. 133 and 200 mg/kg, respectively). A second administration 2 h later effectively increased and maintained higher concentrations during the experimental ischaemia and reperfusion periods. A dose-dependent increase in serum concentration of the drug was observed. Thus, the target therapeutic serum level of lopinavir in the rats was achieved by administrating 10- to 15-fold the standard human dose twice, separated by a 2 h interval.

ABSTRACT Introduction The presence of erectile or ejaculatory dysfunction may indicate physical problems; however, individual perceptions (e.g., sexual satisfaction) may reflect the degree of concern about these changes. Long-term data showing how changes in multiple sexual function domains track together may be useful in understanding the importance of physical declines vs. sexual satisfaction. Aim The aim of this study was to describe changes in sexual function among a population-based sample of aging men. Methods A population-based cohort study using data from the Olmsted County Study of Urinary Symptoms and Health Status among Men. Sexual function was assessed biennially from 1996 to 2004 using a previously validated questionnaire in a random sample of 2,213 men. Main Outcome Measures Changes in erectile function, libido, ejaculatory function, sexual problems, and sexual satisfaction. Results Overall, we observed declines in all of the sexual function domains, ranging from an annual decrease of 0.03 point per year for sexual satisfaction to an annual decrease of 0.23 point per year in erectile function. Moderate correlations were observed among all longitudinal changes in sexual function (range in age-adjusted rs = 0.14–0.43); however, significantly smaller correlations between changes in the functional domains and changes in sexual satisfaction and problem assessment were observed among older men (range in age-adjusted rs = 0.03–0.29). Conclusion Overall, these results demonstrate that longitudinal changes in five sexual function domains change together over time in our community-based cohort. Erectile function, ejaculatory function, and sexual drive decrease over time with greater rates of decline for older men. However, older men may be less likely to perceive these declines as a problem and be dissatisfied. These data may prove helpful to patients and clinicians in understanding and discussing changes in multiple aspects of sexual function.

ABSTRACT Introduction Testosterone replacement therapy has been used in the treatment of sexual dysfunction; however, its use remains controversial, and the effectiveness and long-term health implications are unknown. Aim To evaluate the association between sex hormone serum levels, erectile function, and sexual drive in a population-based sample of men. Methods A stratified random sample of men residing in Olmsted County, Minnesota, completed a questionnaire containing questions from the Brief Male Sexual Function Inventory (BMSFI), and participated in a clinical exam, which included serum hormone measurements. Main Outcome Measures Levels of sexual drive (libido) and erectile function as assessed by the BMSFI and serum testosterone, bioavailable testosterone, and estradiol measurements. Results Out of 414 men, 294 had a regular sexual partner and androgen measurements at the 14th year of follow-up. Total testosterone and erectile function were significantly correlated even after adjustment for age (r = 0.12, P = 0.04). Conversely, total testosterone was not significantly correlated with sex drive (r = 0.08, P = 0.17). Bioavailable testosterone was significantly correlated with both erectile function and sex drive (r = 0.16, P = 0.01 and r = 0.20, P = 0.001, respectively). However, these associations disappeared after age adjustment (r = 0.04 and r = 0.09). Conclusions These cross-sectional results suggest the relationship between sex hormones and sexual function is complex, and that the age-related decline in sexual function may be due to age-related declines in levels of bioavailable testosterone rather than total testosterone levels.