Biomedical subjects

Arnold Melman

Publications and source records attributed to Arnold Melman.

26 records · Page 2Linked to original sources

PubMed2004

Critical surgical techniques for radical perineal prostatectomy.

PURPOSE: Radical perineal prostatectomy was historically the surgical treatment of choice for localized adenocarcinoma of the prostate until the 1980s when radical retropubic prostatectomy began to gain popularity. Nevertheless, the perineal approach possesses advantages that prompt resurgence in the interest of this classic operation. We review the relevant anatomy and our modified technique of performing a successful radical perineal prostatectomy. MATERIALS AND METHODS: The English literature pertaining to the different surgical approaches to radical perineal prostatectomy was reviewed through PubMed. Attention was paid to its indications, anatomical significance and various surgical techniques. RESULTS: Studies demonstrate no difference in the incidence of positive surgical margins and biochemical recurrence between radical retropubic and perineal prostatectomies. Furthermore, the perineal approach avoids the dorsal venous complex and better facilitates the vesicourethral anastomosis in the face of minimal pain and requirement for transfusion. We use a modified Belt approach, aiming to yield the most optimal outcome with minimal morbidity. A meticulous anatomical approach is warranted if complications such as rectal injury, incontinence and erectile dysfunction are to be minimized. CONCLUSIONS: With careful preoperative evaluation, selected patients should benefit from radical perineal prostatectomy for the management of localized prostate cancer. Familiarity with this specialized technique should be an immeasurable addition to any armamentarium in the therapy of prostatic diseases.

Equipment Design↗

PubMed2004

Standards for clinical trials in sexual dysfunctions of women: research designs and outcomes assessment.

INTRODUCTION: Clinical trials on sexual dysfunctions in women are limited in spite of the fact that sexual dysfunctions are likely more common in women than in men. Currently there are no medications approved for treatment in women, and limited data on drug efficacy or psychological efficacy in well-controlled studies. AIM: To provide recommendations/guidelines concerning state-of-the-art knowledge for the research design and outcome assessment standards for clinical trials in women's sexual dysfunctions. METHODS: An International Consultation in collaboration with the major urology and sexual medicine associations assembled over 200 multidisciplinary experts from 60 countries into 17 committees. Committee members established specific objectives and scopes for various male and female sexual medicine topics. The recommendations concerning state-of-the-art knowledge in the respective sexual medicine topic represent the opinion of experts from five continents developed in a process over a 2-year period. Concerning the Standards for Clinical Trials in Women's Sexual Dysfunctions Committee, there were seven experts from two countries. MAIN OUTCOME MEASURE: Expert opinion was based on grading of evidence-based medical literature, widespread internal committee discussion, public presentation and debate. RESULTS: A comprehensive update was created which included references and recommended guidelines for rationale and design of clinical trials, study populations, outcome assessments, protocol design and implementation, data analysis and reporting, as well as ethical and clinical issues related to sexual dysfunction research. CONCLUSIONS: There is a need for more research in developing standards to be used when performing clinical trials and outcomes assessment research in sexual dysfunctions of women.

Consensus↗

PubMed2004

Intracorporal injection of hSlo cDNA restores erectile capacity in STZ-diabetic F-344 rats in vivo.

The ability of gene transfer with the pore-forming subunit of the human maxi-K channel (hSlo) to ameliorate the decline in erectile capacity commensurate with 12-24 wk of streptozotocin (STZ)-diabetes was examined in 181 Fischer-344 rats. A 2-mo period of STZ-diabetes was induced before gene transfer, and erectile capacity was evaluated by measuring the intracavernous pressure response (ICP) to cavernous nerve (CN) stimulation (ranging from 0.5 to 10 mA). In the first series of experiments, ANOVA revealed increased CN-stimulated ICP responses at 1 and 2 mo postinjection of 100 microg pcDNA-hSlo compared with control values. A second series of experiments further examined the dose dependence and duration of gene transfer. The ICP response to submaximal (0.5 mA) and maximal (10 mA) nerve stimulation was evaluated 3 or 4 mo postinjection of a single dose of pcDNA-hSlo ranging from 10 to 1,000 microg. ANOVA again revealed that hSlo overexpression was associated with increased CN-stimulated ICP responses compared with responses in corresponding control animals. Histological studies revealed no immune response to the presence of hSlo. PCR analysis documented that expression of both plasmid and transcript were largely confined to the corporal tissue. In the third series of pharmacological experiments, hSlo gene transfer in vivo was associated with iberiotoxin-sensitive relaxation responses to sodium nitroprusside in corporal tissue strips in vitro. The latter data indicate that gene transfer produces functional maxi-K channels that participate in the modulation of corporal smooth muscle cell tone. Taken together, these observations suggest a fundamental diabetes-related change in corporal myocyte maxi-K channel regulation, expression, or function that may be corrected by expression of recombinant hSlo.

Animals↗

PubMed2003

Radical perineal prostatectomy in obese patients.

OBJECTIVES: To evaluate the efficacy of radical perineal prostatectomy in obese patients. No study has ever been published providing evidence of success of any type of prostatectomy specifically in patients with significant truncal obesity. METHODS: A retrospective review of 103 patients who underwent radical perineal prostatectomy between 1996 and 2002 was performed. Obesity is defined as having a body mass index greater than 30 kg/m(2). Seven obese patients were found. The operative time, blood loss, hospital length of stay, perioperative complications, urinary continence, and quality of specimen were assessed. RESULTS: The mean age was 61 years (range 56 to 67). The body mass index ranged between 30.21 and 47.9 (average 39.27). The average operative time and blood loss was 142 minutes and 542 mL, respectively. No complications occurred and no blood transfusions were needed perioperatively. Two specimens had a positive surgical margin. Six (85.7%) of the 7 patients went home on postoperative day 2; the remaining patient left on day 3. The 1-year continence rate was 66%. CONCLUSIONS: Radical perineal prostatectomy remains an excellent option for obese patients. It remains to be seen if this is the case with radical retropubic prostatectomy.

Aged↗

PubMed2003

Quantitative somatosensory testing of the penis: optimizing the clinical neurological examination.

PURPOSE: Quantitative somatosensory testing, including vibration, pressure, spatial perception and thermal thresholds of the penis, has demonstrated neuropathy in patients with a history of erectile dysfunction of all etiologies. We evaluated which measurement of neurological function of the penis was best at predicting erectile dysfunction and examined the impact of location on the penis for quantitative somatosensory testing measurements. MATERIALS AND METHODS: A total of 107 patients were evaluated. All patients were required to complete the erectile function domain of the International Index of Erectile Function (IIEF) questionnaire, of whom 24 had no complaints of erectile dysfunction and scored within the "normal" range on the IIEF. Patients were subsequently tested on ventral middle penile shaft, proximal dorsal midline penile shaft and glans penis (with foreskin retracted) for vibration, pressure, spatial perception, and warm and cold thermal thresholds. RESULTS: Mixed models repeated measures analysis of variance controlling for age, diabetes and hypertension revealed that method of measurement (quantitative somatosensory testing) was predictive of IIEF score (F = 209, df = 4,1315, p <0.001), while site of measurement on the penis was not. To determine the best method of measurement, we used hierarchical regression, which revealed that warm temperature was the best predictor of erectile dysfunction with pseudo R(2) = 0.19, p <0.0007. There was no significant improvement in predicting erectile dysfunction when another test was added. Using 37C and greater as the warm thermal threshold yielded a sensitivity of 88.5%, specificity 70.0% and positive predictive value 85.5%. CONCLUSIONS: Quantitative somatosensory testing using warm thermal threshold measurements taken at the glans penis can be used alone to assess the neurological status of the penis. Warm thermal thresholds alone offer a quick, noninvasive accurate method of evaluating penile neuropathy in an office setting.

Analysis of Variance↗

PubMed2002

The effect of ovariectomy and long-term estrogen replacement on bladder structure and function in the rat.

PURPOSE The use of estrogen replacement therapy for treating postmenopausal urinary incontinence is a controversial topic. We examined the behavioral, cystometric and histological changes that occur with long-term estrogen depletion and supplementation in rat bladders to determine the role of menopause in lower urinary tract dysfunction. MATERIALS AND METHODS A total of 40 female Sprague-Dawley rats were placed into 1 of 3 groups, including bilateral ovariectomy, bilateral ovariectomy plus estrogen replacement and control. The estrogen replaced group received a 0.25 mg. 16-week sustained release pellet (Innovative Research of America, Sanasota, Florida) placed subcutaneously. After surgery voiding frequency and volume were measured in 24-hour periods by placing animals in metabolic cages. After 16 weeks the rats underwent catheterization and continuous cystometry. The bladder was then removed and stained with Gomori trichrome. The collagen-to-smooth muscle density ratio was calculated for each specimen using current imaging software. RESULTS There was no significant difference in voiding patterns in the 3 groups, as measured by volume and voiding frequency. Cystometric data showed a trend toward higher voiding pressure, threshold pressure, baseline pressure and mean inter-voiding pressure in the ovariectomy group compared with the estrogen and control groups, although there was no statistical significance. Histological studies showed a higher mean collagen-to-smooth muscle ratio plus or minus standard deviation in the ovariectomy group (0.807 +/- 0.204) than in the ovariectomy plus estrogen replacement (0.709 +/- 0.118) and control (0.700 +/- 0.129) groups (p <0.05). Furthermore, when histological and cystometric data were compared for individual samples, we found a direct correlation of mean inter-voiding pressure (a measure of bladder instability) with the collagen-to-smooth muscle ratio (p <0.05). CONCLUSIONS Long-term estrogen replacement is beneficial for treating postmenopausal urinary incontinence.

Animals↗

PubMed2002

Potassium channels and human corporeal smooth muscle cell tone: further evidence of the physiological relevance of the Maxi-K channel subtype to the regulation of human corporeal smooth muscle tone in vitro.

PURPOSE: Recent evidence indicates that the large conductance, voltage dependent, Ca2+ sensitive K channel or Maxi-K has an important role in the modulation of human corporeal smooth muscle tone and, thus, in erectile capacity. We further clarified the contribution of the Maxi-K channel subtype to the generation of contractile responses in isolated human corporeal tissue strips. MATERIALS AND METHODS: We performed pharmacological studies of phenylephrine contracted isolated corporeal tissue strips in the presence and absence of the 2 Maxi-K channel blockers tetraethylammonium chloride (TEA) and charybdotoxin, and the Maxi-K opener NS1619. K channel treatment effects were evaluated using 2 parameters, including 1) the steady state parameter of the empirically determined peak magnitude of the steady state contractile response and 2) the kinetic parameter of time required to achieve half of the peak steady state contractile response or half-time. Electrophysiological studies in freshly isolated and cultured myocytes were performed in parallel to corroborate findings further at the tissue level. RESULTS: Pre-incubating isolated human corporeal tissue strips with 1 mM. TEA and 1 microM. charybdotoxin was associated with an approximate 20% increase in the peak steady state contractile response and a corresponding approximate 20% decrease in the half-time of the phenylephrine induced contractile response. Conversely, pre-incubation with 10 microM. NS1619 produced a significant, approximately 20% decrease in the peak steady state contractile response and an approximate 38% increase in the half-time of the phenylephrine induced contractile response. Adding 30 to 180 microM. NS1619 to phenylephrine pre-contracted smooth muscle strips resulted in a 30% to 50% reduction in steady state contractile tension. No detectable effect of NS1619 was observed in 120 mM. KCl or 100 mM. TEA pre-contracted corporeal tissue strips. Whole cell recordings of freshly isolated and cultured corporeal myocytes confirmed that 30 microM. NS1619 induced a charybdotoxin sensitive hyperpolarizing current mediated by the Maxi-K channel. CONCLUSIONS: These in vitro studies confirm and extend previous observations indicating the importance of the Maxi-K channel for regulating human corporeal smooth muscle tone, and by extension, erectile capacity and function.

Benzimidazoles↗

PubMedDate not supplied

The hemodynamics of erection and the pharmacotherapies of erectile dysfunction.

The past few years have been witness to a sea of change in understanding the diagnosis and treatment of erectile dysfunction. In the wake of Viagra, effective orally administered therapies are now the expected gold standard. Currently available therapies include both peripherally (at the level of the penis) and centrally (brain, e.g., hypothalamic nuclei) acting compounds. When all modes of pharmacotherapy are considered, ranging from oral, to topical, to intraurethral, to intracavernous injection, it is clear that the vast majority of men with mild to moderate erectile dysfunction can now be effectively treated. However, all forms of pharmacotherapy have the lowest efficacy and greatest side effect profiles (including cardiovascular events) in the patients that need the therapy most, that is, those with relatively severe and longstanding erectile dysfunction. The newer generation of pharmacotherapies, which will likely include gene therapy techniques as well, will therefore have to target this latter group. Improved mechanism-based, perhaps patient-specific therapies are foreseen that will dramatically increase the number of patients seeking treatment, as well as the quality of their lives.

Adrenergic alpha-Antagonists↗