Biomedical subjects
Publications and source records attributed to J Rajfer.
Herniation of the ureter occurs infrequently in a sliding inguinal hernia. Massive herniation may cause ureteral obstruction leading to hydronephrosis. Computed tomography can demonstrate both ureteral herniation and associated hydronephrosis.
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The purpose of the study was to utilize axial penile buckling testing as a primary efficacy variable of erection quality during multi-institutional in-office dose titration testing with alprostadil alfadex, prostaglandin E1 (PGE1)-alpha-cyclodextrin, (EDEX /VIRIDAL, Schwarz Pharma) in patients with erectile dysfunction. In 41 study sites, in three different dose titration studies involving 894 patients with impotence >6 months, a buckling test was performed and repeated every 10 min for up to 60 min, within 30 min following alprostadil alfadex administration, or when two consecutive circumference measurements reached maximum values. The buckling device consisted of a standard weight scale attached to a 2 inch diameter plastic cap with a concavity on its ventral surface (H. Eric Richards, Inc., Canton MA). A positive test was associated with absent penile shaft buckling to a downward force of 1.0 kg, slowly applied to the glans in the axis of the erect shaft. A total of 630 (71%) patients experienced at least one positive buckling test. Three consecutive positive buckling tests, implying a functionally rigid erection for at least 20 min, were noted in 521 (58%) patients. There were high correlations between the presence of three consecutive positive buckling tests following alprostadil alfadex injection and the patient's (83% of cases) and the investigator's (88% of cases) evaluation of adequacy of erection for intercourse. Similarly, there were high correlations between the presence of negative buckling tests and the patient's (95% of cases) and the investigator's (96% of cases) evaluation of inadequacy of erection for intercourse. The axial penile buckling test offers a simple, reliable, and inexpensive method to objectively quantify erectile response following in-office dose titration of intracavernosal alprostadil alfadex. The high correlation to subjective patient/investigator assessment adds to the validity of the test.
The major event in normal erectile function is relaxation of the smooth muscle both within the penile arterial system and the cavernosal tissue. The cavernosal smooth muscle is indistinguishable from peripheral vascular smooth muscle from a physiological point of view, ie both are mediated by the NO-cGMP pathway. In man, the major reason for erectile dysfunction (ED) is 'abnormal smooth muscle relaxation', where the smooth muscle of the cavernosa fails to trap blood within the cavernosa (trapping requires a high intracorporeal pressure). The failure of the cavernosal muscle to relax may be due to inadequate stimulation of the muscle or simply non-compliance of the smooth muscle itself. Therefore, attempts to reverse this abnormal smooth muscle relaxation should be directed at either increasing stimulation to the muscle and/or reversing the poor compliance of the muscle tissue itself. Because the major and most efficient pathway for smooth muscle relaxation is the NO-cGMP pathway, any medication that affects this system should prove to be more potent than other alternate pathways of corporal smooth muscle relaxation, as is evidenced from the clinical observations with current intracorporeal instilled drugs. Because the peripheral vascular smooth muscle is indistinguishable physiologically from the muscle of the cavernosal system, any oral drug must be able to differentiate the two smooth muscle compartments to prevent systemic side effects that could render such drugs clinically useless. At the present time, there are no methods to improve smooth muscle compliance but advances in tissue engineering may allow us to accomplish this in the future. International Journal of Impotence Research (2000) 12, Suppl 4, S59-S61.
Penile erection is mediated by nitric oxide (NO) synthesized by the neuronal nitric oxide synthase (nNOS). In the rat penis, the main nNOS mRNA variant, PnNOS, differs from cerebellar nNOS (CnNOS) by a 102 base pair insert encoding a 34-amino acid sequence. In the mouse, two nNOS mRNAs have been identified: nNOSalpha, encoding a 155-kDa protein, and an exon 2-deletion variant, nNOSbeta, encoding a 135-kDa protein that lacks a domain where a protein inhibitor of nNOS (PIN) binds. We wished to determine whether PnNOSalpha and beta are expressed in the rat penis and are located in the nerves and whether the beta form persists in the potent nNOS knock-out mouse (nNOS( big up tri, open big up tri, open)). A PnNOS antibody against the insert common to both PnNOSalpha and beta detected the expected 155-kDa protein in PnNOSalpha-transfected cells. This antibody, and the one common to PnNOS/CnNOS, showed (on Western blots) the 155- and 135-kDa nNOS variants in rat penile tissue during development and aging. PnNOSalpha mRNA and its subvariants were found as the main nNOS in the penile corpora, the cavernosal nerve, and the pelvic ganglia, with lower levels of PnNOSbeta mRNA. In tissue sections, PnNOS protein was immunodetected in the penile nerve endings in the rat and in the nNOS wild-type and nNOS( big up tri, open big up tri, open) mice. An antibody against the sequence encoded by exon 2 did not react (on Western blots) with the 135-kDa band, which confirms that this protein is the beta form. In conclusion, both PnNOSalpha and beta are expressed in the rat penis at all ages and are located in the nerves. The beta form may allow nitric oxide synthesis during erection to be partially insensitive to PIN. The residual expression of PnNOS, and possibly CnNOS, in the penis of the nNOS( big up tri, open big up tri, open) mouse occurs through transcription of the beta mRNA, and this may explain the retention of erectile function when the expression of nNOSalpha is disrupted.
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Hyperprolactinemia from a pituitary adenoma is a rare cause of erectile dysfunction. Men with erectile dysfunction who are found to have a low testosterone level should have a measurement of their prolactin level. Treatment consists of lowering the prolactin level by medication or surgery, or both. Bromocriptine, a dopamine agonist, is efficacious in lowering elevated prolactin levels and can simultaneously shrink these pituitary tumors. With large tumors, transphenoidal surgery may be used to debulk/remove the tumor. Post-treatment prolactin levels can be used to monitor the efficacy of treatment.
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Although erectile function is clearly androgen dependent, is it just as clear at what level of testosterone erectile dysfunction (ED) begins? Does the decline in testosterone that occurs with aging always produce ED? Are exogenous androgens the answer to ED? The answers range from clear to complex.
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CONTEXT: Erectile dysfunction is common in men with diabetes. OBJECTIVE: To assess the efficacy and safety of oral sildenafil citrate in the treatment of erectile dysfunction in men with diabetes. DESIGN: A multicenter, randomized, double-blind, placebo-controlled, flexible dose-escalation study conducted May through November 1996. SETTING: Patients' homes and 19 clinical practice centers in the United States. PATIENTS: A total of 268 men (mean age, 57 years) with erectile dysfunction (mean duration, 5.6 years) and diabetes (mean duration, 12 years). INTERVENTIONS: Patients were randomized to receive sildenafil (n = 136) or placebo (n = 132) as needed, but not more than once daily, for 12 weeks. Patients took the study drug or placebo 1 hour before anticipated sexual activity. The starting dose of sildenafil citrate was 50 mg, with the option to adjust the dose to 100 mg or 25 mg based on efficacy and tolerability, to be taken as needed. MAIN OUTCOME MEASURES: Self-reported ability to achieve and maintain an erection for sexual intercourse according to the International Index of Erectile Function and adverse events. RESULTS: Two hundred fifty-two patients (94%) completed the study (131/136 in the sildenafil group, 121/132 in the placebo group). By intention-to-treat analysis, at 12 weeks, 74 (56%) of 131 patients in the sildenafil group reported improved erections compared with 13 (10%) of 127 patients in the placebo group (P<.001). The proportion of men with at least 1 successful attempt at sexual intercourse was 61 % (71/ 117) for the sildenafil group vs 22% (25/114) for the placebo group (P<.001). Adverse events related to treatment were reported for 22 (16%) of 136 patients taking sildenafil and 1 (1%) of 132 patients receiving placebo. The most common adverse events were headache (11% sildenafil, 2% placebo), dyspepsia (9% sildenafil, 0% placebo), and respiratory tract disorder (6% sildenafil, 2% placebo), predominantly sinus congestion or drainage. The incidence of cardiovascular adverse events was comparable for both groups (3% sildenafil, 5% placebo). CONCLUSION: Oral sildenafil is an effective and well-tolerated treatment for erectile dysfunction in men with diabetes.
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OBJECTIVES: The National Institutes of Health (NIH) category III chronic prostatitis syndromes (nonbacterial chronic prostatitis and prostatodynia) are common disorders with few effective therapies. Bioflavonoids have recently been shown in an open-label study to improve the symptoms of these disorders in a significant proportion of men. The aim of this study was to confirm these findings in a prospective randomized, double-blind, placebo-controlled trial. METHODS: Thirty men with category IIIa and IIIb chronic pelvic pain syndrome were randomized in a double-blind fashion to receive either placebo or the bioflavonoid quercetin 500 mg twice daily for 1 month. The NIH chronic prostatitis symptom score was used to grade symptoms and the quality-of-life impact at the start and conclusion of the study. In a follow-up unblind, open-label study, 17 additional men received 1 month of a supplement containing quercetin, as well as bromelain and papain (Prosta-O), which enhance bioflavonoid absorption. RESULTS: Two patients in the placebo group refused to complete the study because of worsening symptoms, leaving 13 placebo and 15 bioflavonoid patients for evaluation in the blind study. Both the quercetin and placebo groups were similar in age, symptom duration, and initial symptom score. Patients taking placebo had a mean improvement in NIH symptom score from 20.2 to 18.8 (not significant), while those taking the bioflavonoid had a mean improvement from 21.0 to 13.1 (P = 0.003). Twenty percent of patients taking placebo and 67% of patients taking the bioflavonoid had an improvement of symptoms of at least 25%. In the 17 patients who received Prosta-Q in the open-label study, 82% had at least a 25% improvement in symptom score. CONCLUSIONS: Therapy with the bioflavonoid quercetin is well tolerated and provides significant symptomatic improvement in most men with chronic pelvic pain syndrome.
Since the discovery that nitric oxide is the mediator of penile erection, considerable evidence has been accumulated in experimental animals and men regarding the pharmacology and molecular biology of the nitric oxide/cGMP pathway in the penis. This review examines the expression and tissue localization of nitric oxide synthase isoforms (NOS) in this organ and the functional significance of their variants. The disregulation of the balance between nitric oxide synthesis and the compliance of the corpora cavernosa smooth muscle in relation to erectile dysfunction in animal models is discussed. The possible up-regulation of NOS levels and the interaction of NOS variants with protein modulators of their activity is analyzed in the context of novel concepts of gene therapy of erectile dysfunction.
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PURPOSE: To determine the effect of naturally occurring cryptorchidism on testicular histology in both the cryptorchid and normally descended testis from birth to adulthood using the LE/ORL rat model. MATERIALS AND METHODS: Testicular histology was assessed using established morphometric measures in bilaterally descended (BD), unilaterally descended (UD), bilaterally cryptorchid (BC) and unilaterally cryptorchid (UC) testis at days 15, 22, 30, 45 and 60 of age. Testicular mass was also measured at these times. RESULTS: Changes in testicular histology in the BC and UC testes were not noted on or prior to day 30 of age. Significant changes were noted by day 45 of age and continued into adulthood at day 60 of age. There were no histological abnormalities noted in the UD and BD groups. CONCLUSIONS: Since histological changes seen in this animal model occur after the time of testicular descent (day 28 of age), we hypothesize that these changes are due to an abnormal anatomical position of the testis as opposed to an inherent testicular defect in the LE/ORL rat. This hypothesis is supported by the fact that no histological differences were noted between the scrotal testes of unilaterally cryptorchid animals and bilaterally descended control animals.
Transrectal ultrasonography and seminal vesicle aspiration with or without vesiculography have become an integral part of the evaluation and management of the infertile male with ejaculatory duct obstruction. We have found that the Echo Tip Turner Biopsy Needle used in conjunction with ultrasound guidance greatly facilitates these transrectal procedures.