In the penis of the alloxan-induced diabetic rat, eNOS protein expression and synthetic activity were reduced compared with the normal rat penis, independent of testosterone influence and in the absence of significant erectile tissue degenerative changes. These eNOS effects apparently preceded nNOS effects. Full elucidation of the possible mechanisms affecting eNOS function in the diabetic rat penis requires further investigation.
Straightening maneuvers (SM), including manual penile modeling, tunical relaxing incisions and corporal reconstruction using grafting techniques, are occasionally required during inflatable penile prosthesis (IPP) implantation to ensure functional penile straightness. The aim of this study was to compare the outcomes of men undergoing SM employed during IPP implantation compared with those wherein these maneuvers were not required. A retrospective review of 391 patients undergoing IPP implantation at the Johns Hopkins Hospital from January 2000 to December 2011 was performed. Patients in whom some SM was employed (SM, n=93, 23.9% of the overall cohort) were compared with those for whom SM was not required (IPP group, n=298). Seven patients were excluded from final analysis (6 patients with IPPs inserted in neophalli (SM group), and 1 patient with incomplete data (IPP group). Patients in whom a SM was used were younger (55.4 vs 62.3 years), more likely to have Peyronie's disease, and less likely to have prostate cancer, radical prostatectomy or to have previously used erectile aids (all P<0.05). Mean operating room time in the SM group was longer (173.8 vs 152.9 min, P=0.003). Within the SM group, modeling was performed in 40 (43%), tunical relaxing incisions in 37 (39.8%) and tunical reconstruction in 16 (17.2%) (most commonly using allograft dermis or pericardium, or synthetic gore-tex grafts). There were no significant differences in terms of device infection (P=0.15), mechanical failure (P=0.23) or erosion (P=0.96). Although limited in size, this cohort study suggests that IPP implantation in men with penile deformity requiring complex reconstruction to achieve straightening may be done proficiently and without increased adverse outcome risk.
In recent years, a significant body of experimental evidence has accumulated implicating nitric oxide as the central component of a novel signal transduction system that functions in the penis to mediate penile erection. The involvement of nitric oxide in erection physiology appears to be quite complex, involving multiple regulatory interactions: this gaseous molecule has been found to trigger several biochemical events that elicit erectile tissue responses, while a host of modulatory factors have been identified that influence its release and action in erectile tissue. Ongoing investigations in nitric oxide biology in other organ systems also suggest mechanisms which, while yet to be fully established in the penis, may operate significantly to determine the role of nitric oxide in this organ. Further elucidation of cellular and molecular interactions involving nitric oxide effects in the penis can be expected to reveal diverse targets that may serve as a basis for novel pharmacotherapeutic strategies for the future management of erectile dysfunction.
SUMMARYMammary cell differentiation was measured in lactating pipistrelle bats (Pipistrelli.s pipistreillis) by assay of key enzyme activities, and by determination of protein and lactose synthesis rates in short-term tissue cultures. By these criteria, mammary cell differentiation did not change significantly with stage of lactation, but depended on the extent to which the gland was filled with milk. Key enzyme activities and in ritro synthesis rates were significantly higher in glands suckled immediately before tissue collection, compared with contralateral glands that were engorged with milk. This indicates that mammary cell difTerentiation in the lactating bat is regulated locally within each gland by a mechanism sensitive to milk accumulation, to the extent that, unlikc other species, this obscures any underlying effect of stage of lactation.
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