Search PubMed⌕ Search

Biomedical subjects

Tom F Lue

Publications and source records attributed to Tom F Lue.

At least 55 records · Page 3Linked to original sources

Prevention and treatment of erectile dysfunction using lifestyle changes and dietary supplements: what works and what is worthless, part II.

It seems naïve to believe that some plants or herbs do not contain specific compounds that could benefit patients with ED. Many supplements have not been investigated in a laboratory or clinical research setting before commercial sale, however,which creates a complex situation. If efficacy is or is not demonstrated through adequate research, then the benefit or lack thereof cannot be mentioned on the label. Furthermore, clinicians and the public cannot be made aware of which compounds or supplements are effective because no general standards for sale exist under the current guidelines. Dietary supplements have received a tremendous amount of publicity. The large and growing market for ED treatment seems to have contributed partly to the promotion of numerous supplements and their apparent benefits. Whether these dietary supplements have merit is questionable. Some supplements may produce results opposite to those advertised. Other supplements may be enjoying the benefits of the placebo effect. Because a placebo response of 25% to 50% has been recorded in clinical trials with effective agents, it is understandable that some supplements enjoy financial success despite the limited research espousing their use. If one to two of four individuals or one of three individuals who try a dietary supplement gain some benefit for their ED, the market for these supplements will remain extraordinary. On a larger scale, of 100,000 men who try a supplement, approximately 25,000 to 50,000 will claim some success. The challenge for clinicians is to discuss the placebo response properly and the need for good research before any intervention, especially supplements, can be advocated for general use. Table 2 summarizes some popular ED supplements and general conclusions that can be drawn from clinical investigations. Some dietary supplements may have an active ingredient that benefits patients with certain types of ED. An exciting area of future dietary supplement research is the ability of certain agents to have a synergistic effect with prescription agents for ED, thereby improving response rates in men that have failed approved ED therapy initially, especially with oral agents. Randomized clinical trials are the best method of determining which dietary supplements will become a part of conventional medicine. Therefore, more randomized trials for dietary supplements are needed so that they may have the opportunity to become a part of the mainstream milieu, which means that more funding needs to be made available for ED research. The coming years of research should bring enormous excitement and objectivity to this area of medicine.

Adult↗

Obstructive lower urinary tract symptoms correlate with erectile dysfunction.

OBJECTIVES: To examine whether the severity of lower urinary tract symptoms (LUTS), when controlled for other factors, is related to erectile dysfunction (ED) in the male veteran population. Early evidence suggests that LUTS may be associated with ED in men. METHODS: A total of 181 male veterans were prospectively entered into the study. They completed the Sexual Health Inventory for Men (SHIM) and International Prostate Symptom Score (IPSS) questionnaires. Of the 181 men, 144 also underwent uroflowmetry, including determination of the postvoid residual urine volume. Demographic and medical history data were recorded. Pearson correlation coefficients and multiple linear regression analysis were used to examine the relationship between LUTS and ED, as well as the effects of age and comorbidities. RESULTS: The correlation coefficient (r) for the SHIM score with the total IPSS was -0.17 (P = 0.023); with the obstructive IPSS, it was -0.20 (P = 0.006); and with the irritative IPSS, -0.05 (P = 0.492). Age was the only other factor with a statistically significant correlation with the SHIM score (r = -0.23, P = 0.002). Multiple linear regression modeling showed obstructive IPSS (P = 0.001) and depression (P = 0.017) to be the only statistically significant predictors of the SHIM score. A consistent negative correlation was found between obstructive IPSS and the SHIM score across age groups, with the strongest effect for men aged 60 to 70 years (r = -0.412, P = 0.003). CONCLUSIONS: Obstructive LUTS correlated with, and were predictive of, ED, even after controlling for age and comorbidities. Although age correlated with ED, it did not add to the power of the multiple linear regression model composed of obstructive IPSS and depression.

Adult↗

Androgen, estrogen, and progesterone receptor gene regulation during diabetic erectile dysfunction and insulin treatment.

OBJECTIVES: To determine whether altered levels of sex hormone receptor genes (androgen, estrogen, and progesterone receptors) are involved in the etiology of diabetes-related erectile dysfunction. Insulin treatment can restore erectile function through modulation of sex hormone receptor genes. METHODS: Diabetes was induced in rats (n = 40) by intraperitoneal injection of streptozotocin. The diabetic rats were divided into two groups: untreated rats (n = 20) and rats treated daily with 10 U subcutaneous human recombinant insulin (n = 20). Control nondiabetic rats (n = 20) were given only vehicle. Erectile function was analyzed by measurement of intracavernous pressure. Gene and protein expression of sex hormone receptors were analyzed by reverse transcriptase-polymerase chain reaction and immunohistochemistry, respectively. RESULTS: The mean intracavernous pressure was significantly decreased in the diabetic rats compared with the controls and was restored to normal after insulin treatment. In the diabetic rat crura, mRNA and protein expression for estrogen receptor-beta and progesterone receptor were significantly lower than in the control crura, and the expression profile of androgen receptor and estrogen receptor-beta did not change. Insulin treatment restored estrogen receptor-beta and progesterone receptor mRNA and protein expression. Insulin treatment significantly increased the expression of mRNA and protein for androgen receptor and estrogen receptor-alpha in diabetic rats compared with control rats. CONCLUSIONS: This is the first study to demonstrate that insulin treatment may restore erectile function through restoration of sex hormone receptor gene and protein expression in the diabetic rat crura.

Animals↗

Erectile dysfunction and priapism.

BACKGROUND: A 46-year-old man presented with erectile dysfunction following a blunt perineal injury sustained 1 year previously. Oral phosphodiesterase type 5 inhibitors failed to improve his erections. The remainder of the patient's history, physical examination and laboratory tests were unremarkable except for a moderate tenderness in the left perineum and some 'fullness' in the corpora cavernosa during physical examination. INVESTIGATION: Physical examination, color duplex ultrasound of the penis and perineal area and Sexual Health Index for Men questionnaire. DIAGNOSIS: Non-ischemic priapism due to a ruptured left helicine artery, intermittent penile turgidity and erectile dysfunction. MANAGEMENT: Open suture ligation of the helicine artery and imbrication of the pseudocapsule.

Humans↗

Peyronie's disease: advancements in recent surgical techniques.

PURPOSE OF REVIEW: The aim of this review is to discuss the recent advances in surgical techniques for the correction of Peyronie's disease. A review of the literature published in 2002 and 2003 regarding surgical treatment was performed in preparation for this article. RECENT FINDINGS: The surgical treatment of Peyronie's disease remains a debated topic. Generally, surgical therapy for Peyronie's disease can be divided into three main categories: wedge resection/plication surgeries; plaque excision/incision with grafting procedures; and the placement of a penile prosthesis. New reports have investigated suture selection, graft acceptability, and new surgical approaches. These new surgical enhancements will give urologists a greater choice in the surgical management of Peyronie's disease. This will aid the ability of the urologist to tailor the therapy necessary for each individual patient. SUMMARY: The correction of acquired penile deformity seen in Peyronie's disease patients can be a challenge for the practising urologist. Newer advancements in surgical techniques and materials will allow the urologist greater treatment options. The degree of curvature, the type of deformity, erectile dysfunction, and penile length are all characteristics that are assessed in choosing the best surgical intervention in Peyronie's disease. Surgical therapy can be quite beneficial for patients who suffer from penile deformity and can greatly improve their quality of life.

Humans↗

Combined penile plication surgery and insertion of penile prosthesis for severe penile curvature and erectile dysfunction.

PURPOSE: For persistent penile curvature after corporeal dilation and prosthesis placement other maneuvers, such as plaque incision with or without grafting, or penile modeling, must be used to complete penile straightening. However, each of these techniques is associated with increased morbidity, which includes higher rates of infection and urethral injury. We describe a new technique for correcting severe penile curvature and erectile dysfunction using combined penile plication and placement of a 3 piece inflatable penile prosthesis. MATERIALS AND METHODS: Between February 2000 and June 2003, 5 patients with erectile dysfunction and severe curvature for which other treatment modalities had failed were treated with combined inflatable penile prosthesis and additional plication to correct the severe malformation. Detailed medical and sexual history was obtained as well as preoperative duplex ultrasound prior to surgery. RESULTS: The age range of our patient population was 22 to 55 years. In each case penile prosthesis placement was insufficient to correct the malformation and the addition of multiple plication sutures was required. The malformation in all patients was corrected with this technique. To date no patients have reported any complications with followup (range 3 to 36 months). CONCLUSIONS: In cases of severe penile deformity and curvature with erectile dysfunction the combination of penile plication and inflatable penile prosthesis placement is a method of repair that is well tolerated.

Adult↗

The effect of neural embryonic stem cell therapy in a rat model of cavernosal nerve injury.

OBJECTIVE: To isolate embryonic stem cells that have differentiated along the neuronal cell line, and to assess whether injecting these neural stem cells into the corpus cavernosum influences cavernosal nerve regeneration and functional status. MATERIALS AND METHODS: Embryonic neural stem cells were obtained; 26 male Sprague-Dawley rats were divided into four groups: five had a sham operation; eight (controls) had a bilateral cavernosal nerve crush and injection of culture medium into the corpora cavernosa; four had an injection of neural embryonic stem (NES) cells into the major pelvic ganglion (MPG); and nine had bilateral cavernosal nerve crush and injection of NES cells into the corpora cavernosa. Erectile response was assessed by cavernosal nerve electrostimulation at 3 months, and penile tissue samples were evaluated histochemically for nitric oxide synthase (NOS)-containing fibres, tyrosine hydroxylase and neurofilament staining. RESULTS: The groups injected with NES cells into the MPG and corpora cavernosa had significantly higher intracavernosal pressures than the control group. Immunohistochemical staining also revealed differences in the quality of the NOS-containing nerve fibres. Neurofilament staining was significantly better in the experimental groups injected with NES cells. CONCLUSION: We were able to isolate embryonic stem cells that had differentiated along the neural cell line and, using these NES cells intracavernosally, showed improved erectile function in a rat model of neurogenic impotence.

Animals↗

Summary of the recommendations on sexual dysfunctions in men.

INTRODUCTION: There are few published guidelines for the management of sexual dysfunctions in men and women, despite the prevalence and lack of attention to these problems. Disorders of sexual function in men include erectile dysfunction, orgasm/ejaculation disorders, priapism, and Peyronie's disease. AIM: To provide evidence-based and expert-opinion consensus guidelines for the clinical management of men's sexual dysfunctions. METHODS: An International Consultation in collaboration with major urological and sexual medicine societies assembled over 200 multidisciplinary experts from 60 countries into 17 consultation committees. Committee members established the scope and objectives for each chapter. Following intensive review of available data and publications, committees developed evidence-based guidelines in each area. MAIN OUTCOME MEASURE: New algorithms and guidelines for assessment and treatment of men's sexual dysfunction were developed. The Oxford system of evidence-based review was systematically applied. Expert opinion was based on systematic grading of the medical literature, in addition to cultural and ethical considerations. RESULTS: Recommendations and guidelines for men's sexual dysfunction are presented. These guidelines were developed as evidence-based, patient-centered, and multidisciplinary in focus. For the clinical assessment and diagnosis of ED, a basic evaluation was recommended for all patients, with optional and specialized testing reserved for special cases. A new treatment algorithm is proposed. This algorithm provides a clinically relevant guideline for managing ED in the large majority of men. New treatment guidelines and algorithms are provided for men's orgasm and ejaculation disorders, including premature ejaculation, retrograde and delayed ejaculation. Finally, expert opinion-based guidelines for the clinical management of priapism and Peyronie's disease are provided. CONCLUSIONS: Additional research is needed to validate and extend these guidelines. Nonetheless, this summary encompasses the recommendations concerning men's sexual dysfunctions presented at the 2nd International Consultation on Sexual Medicine in Paris, France, June 28-July 1, 2003.

Algorithms↗

Longitudinal differences in disease specific quality of life in men with erectile dysfunction: results from the Exploratory Comprehensive Evaluation of Erectile Dysfunction study.

PURPOSE: We assessed the impact of erectile dysfunction therapy on 1-year health related quality of life using a validated erectile dysfunction specific instrument. MATERIALS AND METHODS: Using an observational erectile dysfunction registry clinical, sociodemographic and health related quality of life information was collected at baseline, and 3, 6 and 12 months later. Only men who reported undergoing erectile dysfunction treatment were included in this analysis sub-sample. Patients were classified as treatment responders based on improvements in International Index of Erectile Function scores. Changes in health related quality of life scores from baseline were compared between responders and nonresponders. RESULTS: The cohort consisted of 89 patients, of whom 40 (45%) responded to therapy by International Index of Erectile Function criteria. Responders and nonresponders had comparable baseline disease severity and health related quality of life. At 1 year responders reported significantly better health related quality of life and greater improvement from baseline in sexual experience (mean change -1.64 versus 3.19) and emotional life (mean -3.01 for responders versus 1.75) domains of the Psychological Impact of Erectile Dysfunction scales (p <0.01). This 4.5 to 5 point difference in mean change score (1/2 SD) was considered moderately clinically significant. CONCLUSIONS: Men who respond to erectile dysfunction treatment report significantly better health related quality of life 1 year after initial presentation for erectile dysfunction than nonresponders. This finding should motivate providers to be more proactive in diagnosing and treating men with erectile dysfunction since successful therapy appears to improve health related quality of life. These data suggest that men in whom primary therapy for erectile dysfunction fails should be offered secondary treatment because many men in this study in whom previous therapies failed reported improved health related quality of life when they began effective secondary treatment.

Adult↗

Peyronie's disease: a review.

PURPOSE: We provide a current review of Peyronie's disease. MATERIALS AND METHODS: We reviewed the world peer reviewed literature on the pathology, pathogenesis, diagnosis and treatment of Peyronie's disease. RESULTS: The incidence of Peyronie's disease has continuously increased during the last 30 years. However, fewer patients need prosthesis surgery as the sole treatment option because of earlier diagnosis, improved medical therapy, refinement in surgical technique and better understanding of the basic sciences of the disease. CONCLUSIONS: Currently patients with Peyronie's disease have had improvements in prognosis and experienced an expansion of the available therapeutic options.

Cell Differentiation↗

The effect of vascular endothelial growth factor and adeno-associated virus mediated brain derived neurotrophic factor on neurogenic and vasculogenic erectile dysfunction induced by hyperlipidemia.

PURPOSE: We examined neurogenic and vasculogenic erectile dysfunction associated with hypercholesterolemia and evaluated vascular endothelial growth factor (VEGF) and adeno-associated virus (AAV) mediated, brain derived neurotrophic factor (BDNF) for potential treatment. MATERIALS AND METHODS: A total of 21, 2-month-old male rats were fed a 2% cholesterol diet and another seven were fed a normal diet. Two months later serum cholesterol levels were measured and test agents were given intracavernously. Those on normal diet (controls) received phosphate buffered saline (PBS). Those on cholesterol diet were randomly divided into 3 groups receiving PBS, VEGF (4 microg.) or AAV-BDNF (10 viral particles). Four months later erectile function was evaluated and cavernous tissues were collected for erectile dysfunction and immunohistochemical staining. RESULTS: Serum cholesterol levels were higher in rats fed the high fat diet than in controls. Intracavernous pressure was lower in cholesterol plus PBS treated rats than in rats of the other 3 groups. All hypercholesterolemic rats had less nerve content, fewer endothelial cells and higher smooth muscle content than rats with normal cholesterol levels. In cholesterol plus PBS treated rats electron microscopy showed hypermyelination and severe atrophy of axons, a remarkable decrease in the number and size of nonmyelinated axons, disarray of the smooth muscle cells with scant myofilaments and foamy cytoplasm, and denuded endothelial lining of the sinusoids covered by numerous platelets. VEGF and AAV-BDNF appeared to alleviate partially these changes. CONCLUSIONS: A high fat diet caused erectile dysfunction with accompanying neurological and vascular changes. VEGF and AAV-BDNF seemed to alleviate these problems.

Adenoviridae↗

Up and down-regulation of phosphodiesterase-5 as related to tachyphylaxis and priapism.

PURPOSE: We identify whether tachyphylaxis and priapism effects of sildenafil are related to regulation of phosphodiesterase-5 (PDE-5) expression. MATERIALS AND METHODS: Cavernous smooth muscle cells (CSMCs) were isolated from young rats and treated with 0, 1, 10 and 25 microM sildenafil with or without 100 microM of sodium nitroprusside for 3 and 7 days. The cells were subjected to reverse transcriptase-polymerase chain reaction and Western blot analysis for PDE-5 expression. Plasmid constructs carrying PDE-5A1 and PDE-5A2 promoters were transfected into COS-7 cells, treated with 25 microM sildenafil and analyzed for promoter activities. To simulate priapism, CSMCs were cultured under anoxia or hypoxia and then analyzed for PDE-5 expression. Furthermore, rats underwent bilateral pudendal arterial ligation for 1 day to 14 weeks, and corpus cavernous tissues were subjected to reverse transcriptase-polymerase chain reaction analysis for PDE-5 expression. RESULTS: Up-regulation of PDE-5 was noted in CSMCs treated with 25 microM sildenafil for 7 days. PDE-5 messenger RNA and protein levels were significantly increased in the 7-day sildenafil treated cultures. Sodium nitroprusside appeared to down-regulate PDE-5 expression. Sildenafil significantly increased the activities of PDE-5A1 promoter. PDE-5 expression was significantly reduced under anoxia and hypoxia. The corpus cavernous tissue showed a gradual decrease in PDE-5 expression under ischemia. CONCLUSIONS: Repeated treatment with sildenafil at high concentrations was needed to simulate tachyphylaxis in our cell culture system. Adequate oxygenation was important for PDE-5 expression. Thus, sicklemic patients may express PDE-5 at abnormally low levels, predisposing them at risk of stuttering priapism.

3',5'-Cyclic-GMP Phosphodiesterases↗

Do impotent men with diabetes have more severe erectile dysfunction and worse quality of life than the general population of impotent patients? Results from the Exploratory Comprehensive Evaluation of Erectile Dysfunction (ExCEED) database.

OBJECTIVE: Little is known regarding how diabetic men with erectile dysfunction (ED) differ from the general population of impotent men. The primary objective of this study was to compare disease-specific health-related quality of life (HRQOL) and severity of ED in impotent men with and without diabetes. RESEARCH DESIGN AND METHODS: Validated functional and HRQOL questionnaires (including the International Index of Erectile Function, the Sexual Self-Efficacy Scale, and the Psychological Impact of Erectile Dysfunction scales) were administered to patients in an ED disease registry. Men with ED and a history of diabetes (n = 20) were compared with men with ED and no history of diabetes (n = 90) at baseline and at the 12-month follow-up. RESULTS: Diabetic impotent men reported worse erectile function and intercourse satisfaction at baseline, and ED had a greater impact on their emotional life. Diabetic men with ED had significantly different trends over time in the Erectile Function (P < 0.001), Intercourse Satisfaction (P < 0.013), Sexual Desire (P < 0.016), Overall Satisfaction (P < 0.023), and the Sexual Experience-Psychological Impact domains (P < 0.002). In addition, there was a trend toward a difference over time in the Emotional Life-Psychological Impact domain (P < 0.067). CONCLUSIONS: Impotent men with diabetes present with worse ED than nondiabetic men with ED, resulting in worse disease-specific HRQOL in the diabetic men. Although diabetic patients initially respond well to ED treatment, responses do not appear to be durable over time. Therefore, clinicians must provide longer-term follow-up when treating ED in diabetic patients.

Age of Onset↗