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Biomedical subjects

Manoj Monga

Publications and source records attributed to Manoj Monga.

At least 73 records · Page 4Linked to original sources
PubMed2003

Is there a role for pentosan polysulfate in the prevention of calcium oxalate stones?

The clinical role for pentosan polysulfate (PPS) in the prevention of calcium oxalate urolithiasis is not known. Crystallization and aggregation are important steps in calcium oxalate stone formation, and PPS has been shown to inhibit these steps, both in vitro and in vivo. In addition, PPS has a role in repairing injured urothelium and inhibiting adhesion to epithelial defects. A randomized double-blind placebo-controlled study appears warranted to assess the utility of PPS in the prevention of recurrent calcium oxalate stones.

Administration, Oral↗
PubMed2003

Surgical management of the calyceal diverticulum.

PURPOSE OF REVIEW: The management of calyceal diverticulum has evolved from an open surgical approach to a minimally invasive approach. Currently, the percutaneous, ureteroscopic and laparoscopic techniques are recommended by individual investigators. Recent studies have helped establish patient selection criteria for each of the above procedures. This review will discuss technique and results and suggest a treatment algorithm for the patient with a symptomatic calyceal diverticulum. RECENT FINDINGS: Excellent long-term success has been reported with all three minimally invasive modalities. Percutaneous ablation of the calyceal diverticulum is the most established minimally invasive technique for this disorder. A direct puncture into the calyceal diverticulum is recommended. Limitations exist primarily for an anteriorly located diverticulum. In this situation, if the diverticulum is in a superior anterior calyx, a ureteroscopic approach is recommended while if the diverticulum is in a middle or lower pole calyx, a laparoscopic approach is recommended. SUMMARY: This review suggests that experience and expertise in percutaneous, ureteroscopic and laparoscopic techniques provide the urologist with the best opportunity to individualize treatment approach based on location and size of the diverticulum. A treatment algorithm based on these parameters may be helpful in patient counseling and decision-making.

Clinical Trials as Topic↗
PubMed2003

Laboratory evaluations of erectile dysfunction: an evidence based approach.

PURPOSE: We evaluate the prevalence of laboratory abnormalities in men presenting for initial evaluation and therapy of erectile dysfunction. MATERIALS AND METHODS: The computerized charts of men receiving treatment for erectile dysfunction from 1987 to 2002 were retrospectively reviewed. We pooled laboratory data for 3,547 men with erectile dysfunction to assess the prevalence of laboratory abnormalities. Values of the common laboratory screening tests for erectile dysfunction were recorded for testosterone, prolactin, luteinizing hormone, thyroid-stimulating hormone, hemoglobin A(Ic), prostate specific antigen, hemoglobin, cholesterol and creatinine. RESULTS: Of those patients evaluated 18.7% had low testosterone, 4.6% had increased prolactin, 14.6% had abnormal luteinizing hormone, 4.0% had increased thyroid-stimulating hormone, 8.3% had increased prostate specific antigen, 26.5% had anemia and 11.9% tested had renal insufficiency. A high percentage of patients presenting with a primary complaint of erectile dysfunction had increased hemoglobin A(Ic) and total serum cholesterol levels (52.9% and 48.4%, respectively). CONCLUSIONS: An evidence based approach to standardization of laboratory evaluations for men presenting with erectile dysfunction is recommended. Laboratory screening should be directed to identify those risk factors that may benefit from lifestyle modification and pharmacological intervention.

Aged↗
PubMed2003

Psychogenic erectile dysfunction.

OBJECTIVE: To educate healthcare professionals on the historical aspects, clinical diagnosis, and current treatment methods of psychogenic erectile dysfunction. METHOD: A topic review of current literature was performed. Chief sources included primarily mainstream journals in the fields of urology, psychiatry/psychology, impotence/erectile dysfunction, epidemiology, and internal medicine. MEDLINE and PsycINFO databases were utilized. DATA EXTRACTION: Data from clinical studies, trials, and review articles concerned primarily with psychological aspects of the arousal (erectile function) phase of the male sexual response cycle were collected, analyzed, and summarized in this review article. RESULTS: There has been a shift in how erectile dysfunction has been perceived and treated over the past 30 years. With the current focus now on the very prevalent organic causes of ED, psychological factors are increasingly overlooked, though they remain important to the treatment of the patient as a whole. This article provides a complete, concise review of the interplay between psychological components and erectile function, reviews the work-up and diagnosis of psychogenic ED, and discusses treatment methods. CONCLUSIONS: Erectile dysfunction is a prevalent problem that can affect, and can be affected by, psychosocial aspects of a man's life. Medical or pharmacological interventions are often appropriate to treat ED, but the psychosocial aspects should not be ignored. It has become easier for practitioners to put aside patients' psychosocial and interpersonal concerns regarding sexual health. Clinicians provide the best possible treatment if they recognize that erectile dysfunction is a complex, multifactorial disorder, and treat accordingly.

Cognitive Behavioral Therapy↗
PubMed2002

Small intestinal submucosa as a tunica albuginea graft material.

PURPOSE: We evaluated the morphological, immunological and functional response to small intestinal submucosa grafting of the tunica albuginea to determine its potential as a grafting material for penile surgery. MATERIALS AND METHODS: Male New Zealand White rabbits underwent a sham procedure (6) or tunical excision and grafting with small intestinal submucosa (6). The erectile response to the intracavernous vasoactive agents sodium nitroprusside plus a papaverine, phentolamine and prostaglandin E1 combination (Sigma Chemical Co., St. Louis, Missouri) was evaluated 45-day postoperatively. The area under the graft was evaluated for stromal collagen and smooth muscle content by Masson's trichrome stain. Protein expression of smooth muscle specific alpha-actin and the inflammatory markers inducible nitric oxide synthase (NOS) and transforming growth factor-beta1 (TGF-beta1) was evaluated by immunohistochemical methods. Total RNA was extracted from the corpora cavernosum underlying the small intestinal submucosa graft and reverse transcriptase-polymerase chain reaction (RT-PCR) was done using an Access system (Promega, Madison, Wisconsin) with gene specific primers for inducible NOS, TGF-beta1 and vascular endothelial growth factor (VEGF). RESULTS: Grafting of the tunica albuginea with small intestinal submucosa had no significant effect on the magnitude or duration of the erectile response to intracavernous vasoactive agents. Histological examination demonstrated no inflammatory changes in the tunica albuginea or corporeal tissue underlying the area of the small intestinal submucosa graft and there was no appreciable alteration in smooth muscle or collagen content. The 2 groups showed intense positive immunostaining to alpha-actin. Weak expression of TGF-beta1 predominantly associated with smooth muscle fibers was identified in the 2 groups of rabbits by immunostaining and RT-PCR. No significant inducible NOS was detected by immunostaining or RT-PCR in either group. Strong VEGF expression was observed in grafted rabbits. The most noticeable (3-fold) increase in expression was detected in splice variant 165. CONCLUSIONS: Small intestinal submucosa grafting of the tunica albuginea preserves the duration and magnitude of the erectile response to vasoactive agents. This type of tunical grafting does not stimulate a significant inflammatory response, or cause corporeal fibrosis or loss of cavernous smooth muscle content. Stimulating VEGF may facilitate wound healing and the maintenance of normal erectile function.

Actins↗
PubMed2002

Vasoactive agents induce cytotoxicity in cultured human penile smooth muscle cells.

OBJECTIVES: To evaluate the direct in vitro cytotoxicity of vasoactive agents (papaverine, phentolamine, and prostaglandin E(1) [PGE(1)]) to human penile cavernosal smooth muscle cells. Intracavernous pharmacotherapy with vasoactive agents for male erectile dysfunction has been associated with long-term complications such as a reduction in penile smooth muscle content and fibrosis. METHODS: Human penile cavernosal tissue explants (1 to 2 mm(3) size) were obtained with proper institutional review board approval from patients undergoing penile prosthesis implantation. Primary culture was initiated in Dulbecco's modified Eagles medium containing 10% fetal bovine serum, and monolayer cavernosal cells were grown in 48-well tissue culture dishes. At 60% to 80% confluence, cells were labeled overnight with (51)Na(2)CrO(4) (1.5 microCi) and then incubated with therapeutic concentrations of papaverine (1.5 to 30 mg/mL), phentolamine (0.5 mg/mL), and PGE(1) (5 microg/mL) alone, as well as in combination, for 30 minutes at 37 degrees C. At the end of incubation, an aliquot of supernatant was collected in scintillation vials. The release of cell-free chromium in supernatants was determined in a liquid scintillation counter, and results were expressed as the percentage of cytotoxicity. RESULTS: Papaverine induced a significant dose-dependent increase in chromium release from the cavernosal cells. At therapeutic concentrations, papaverine (30 mg/mL) produced up to 60% cytotoxicity; PGE(1) (5 microg/mL) resulted in 40% toxicity. The combination of papaverine with either PGE(1) or phentolamine had a cumulative toxic effect, and maximal toxicity (70%) was observed with the triple combination. CONCLUSIONS: Papaverine-induced cytotoxicity to cavernosal smooth muscle cells may contribute to the fibrosis and loss of smooth muscle content associated with the intracavernous pharmacotherapy. Quantitative evaluation of in vitro cytotoxicity in human cavernosal smooth muscle cell culture may be important in the development of new intracavernosal vasoactive agents.

Antihypertensive Agents↗
PubMed2002

Community-based study of erectile dysfunction and sildenafil use: the Rancho Bernardo study.

OBJECTIVES: To evaluate erectile dysfunction (ED) using a validated self-administered 5-item questionnaire (5-item version of the International Index of Erectile Function [IIEF-5]) and the use of sildenafil in community-dwelling older men. METHODS: In October 1998, the IIEF-5 was mailed to all surviving members of an established community-based cohort of older men. The degree of ED was stratified by the erectile function domain score as complete (4 or less), severe (5 to 10), moderate (11 to 14), mild (15 to 18), or none (19 to 20). Men were also asked about sildenafil use and its effectiveness. RESULTS: A total of 976 men (64%) responded to the questionnaire. The internal consistency of the questionnaire construct was confirmed, with a Cronbach's alpha coefficient of 0.96 for all 5 questions. Eighty-nine percent of men younger than 50 years were sexually active compared with 37% of men older than age 80. Twenty-six percent of sexually active men reported complete (3%), severe (10.5%), or moderate (12.6%) ED. The prevalence of moderate or complete ED increased with age and was reported by 58% of men aged 75 to 79 years. Eleven percent of sexually active men had used sildenafil one or more times, with 63% reporting good or "terrific" effects and 11% reporting no benefit. The response to sildenafil deteriorated with age and increasing degree of ED. CONCLUSIONS: The results of this community-based study confirm the strong correlation between advancing age and the prevalence and degree of ED, with 33% of men aged 75 and older reporting at least moderate ED. Nevertheless, more than 33% of men older than 75 years remained sexually active. Of the 660 sexually active men, 81% reported satisfaction with sexual intercourse; only 11% had tried sildenafil.

Adult↗
PubMed2002

Bare naked baskets: optimizing ureteroscopic stone extraction.

Baskets placed through the working channels of flexible ureteroscopes limit mobility and irrigant flow. We describe a new technique to minimize these limitations. An unsheathed "bare naked" basket affords enhanced ureteroscopic efficacy by limiting obstruction of the working channel. We have used the technique clinically to treat stones in difficult locations successfully and to remove fragments of calculi after ureteroscopic lithotripsy.

Equipment Design↗
PubMed2002

Comparison of intrarenal pressure and irrigant flow during percutaneous nephroscopy with an indwelling ureteral catheter, ureteral occlusion balloon, and ureteral access sheath.

OBJECTIVES: To determine the differential effects on renal pressures and irrigation flow associated with the application of different ureteral catheters during percutaneous nephrolithotomy. METHODS: Using ex vivo fresh cadaveric tissue, we established a percutaneous nephrolithotomy model. After obtaining lower pole percutaneous access, we recorded the pressure and irrigant flow measurements. Measurements were made with an empty ureter, 6F ureteral catheter, occlusion balloon catheter, and ureteral access sheaths (10/12F and 12/14F). Three 1-minute trials for each condition were recorded in each of four kidneys. RESULTS: Ureteral catheterization with both the 10/12F and the 12/14F ureteral access sheaths resulted in significantly decreased intrarenal pressures in the pressure range tested compared with an empty ureter, a ureteral catheter, or an occlusion balloon application. Total irrigant flow for the 12/14F ureteral access sheath was significantly higher than for the empty ureter, ureteral catheter, or occlusion balloon in the entire pressure range evaluated. CONCLUSIONS: In this in vitro cadaveric model, application of the ureteral access sheath during percutaneous nephrolithotomy resulted in decreased intrarenal pressures and increased irrigant flow.

Catheterization↗
PubMed2002

Urology practice patterns after residency training in radical perineal prostatectomy.

OBJECTIVES: To assess the impact of residency training in radical perineal prostatectomy (RPP) on subsequent use of RPP in urology practice. METHODS: Urologists who completed residency training at Tulane University and the University of California, San Diego, Medical Center from 1977 to 1999 were surveyed by anonymous questionnaire for their practice demographics, operative experience in RPP during residency, the role of RPP in their current practice, and the reasons they do or do not perform RPP. RESULTS: Of 91 former residents, 61 (67%) responded. RPP was in current use by 41% of the urologists trained in RPP during residency and by 13% of those with no residency RPP training. Those who had performed 10 or more RPPs during residency reported a higher rate of current RPP use (53%) than did those who had performed fewer than 10 RPPs during residency (21%). Urologists trained in RPP during residency cited partner preference (28%) and inadequate exposure (26%) as reasons they did not perform RPP; respondents with no residency RPP training cited inadequate exposure (25%), difficulty of the operation (25%), and time required to perform the operation (25%). CONCLUSIONS: A urologist with residency training in RPP is more likely to perform RPP in practice than is a urologist without such training. The intensity of training, in the form of greater operative experience during residency, had a positive impact on the future use of this specialized surgical technique.

Group Practice↗
PubMed2002

Maximizing ureteroscope deflection: "play it straight".

We studied simple maneuvers to optimize active deflection of the flexible ureteroscope. Up to 61 degrees of active deflection is lost if the ureteroscope is not kept in a straight alignment. Holding the ureteroscope taut, placing a super-stiff guidewire in the working channel, or using an access sheath maximizes active deflection.

Humans↗
PubMed2002

Sexual dysfunction in combat veterans with post-traumatic stress disorder.

OBJECTIVES: To evaluate the prevalence, clinical correlates, and severity of sexual dysfunction in combat veterans with and without post-traumatic stress disorder (PTSD) using a validated instrument for assessing sexual function. The results of recent studies have suggested that combat veterans with PTSD experience a higher rate of sexual dysfunction than do those without PTSD. METHODS: We administered the International Index of Erectile Function (IIEF) and a demographic and health questionnaire to male combat veterans undergoing treatment for PTSD and to age-comparable male combat veterans without PTSD. RESULTS: The mean total IIEF score was significantly lower in the 44 patients with PTSD than in the 46 controls (26.38 versus 40.86; P = 0.035). With respect to the individual IIEF domains, patients with PTSD had poorer scores on overall satisfaction and orgasmic function and showed trends toward poorer scores on intercourse satisfaction and erectile function. No statistically significant difference was observed for sexual desire. The rate of erectile dysfunction was 85% in patients with PTSD and 22% in controls. Moderate to severe erectile dysfunction was present in 45% of the patients with PTSD and in only 13% of controls. Significantly more patients with PTSD (57%) than controls (17%) were using psychotropic medications. CONCLUSIONS: Combat veterans with PTSD experience a significantly higher rate of sexual dysfunction than do veterans without PTSD and show impairment in some, but not all, specific domains of sexual function. The IIEF may be useful in evaluating the response to treatment of erectile dysfunction. Clinicians should proactively address the sexual concerns of combat veterans with PTSD.

Adult↗
PubMed2002

Effect of argon-beam coagulation on the integrity of suture material.

PURPOSE: To evaluate the effect of argon-beam coagulator (ABC) energy on suture materials. MATERIALS AND METHODS: Six absorbable and nonabsorbable suture materials (polyglactin, chromic catgut, polydioxanone, silk, poliglecaprone, and Gore-Tex) were placed under tension and exposed to ABC energy to determine breaking times. Subsequently, all suture materials were exposed to limited ABC energy, and tensiometry was used to determine decreases in breaking strengths. RESULTS: Among the suture materials tested, Gore-Tex was the most resistant to ABC energy. Although absorbable suture materials were less resistant than nonabsorbable suture materials, 2-0 polyglactin manifested the greatest resiliance to deterioration with ABC energy exposure. CONCLUSIONS: The ABC has differential effects on suture materials. Larger-gauge suture materials are more resistant to ABC than smaller materials. Similarly, nonabsorbable sutures are generally more resilient to ABC energy than absorbable materials. Among the suture materials evaluated in our in vitro model, 2-0 Gore-Tex was best suited for vascular ligation, and 2-0 polyglactin is optimal for renal collecting system closure if ABC is anticipated as an adjunct for hemostasis.

Absorbable Implants↗
PubMed2002

Urology practice patterns after residency training in laparoscopy.

PURPOSE: Laparoscopic training has been incorporated into many urology residency programs. Although the impact of laparoscopic training courses has been examined, the impact of residency training in laparoscopy on subsequent urology practice patterns has not been assessed. MATERIALS AND METHODS: Urologists completing their residency from 1977 through 1999 at Tulane University and the University of California-San Diego were sent anonymous questionnaires in September 2000. The questionnaires evaluated practice demographics, operative experience in laparoscopy during residency, and the role of laparoscopy in the urologist's current practice. Factors impacting the decision to perform or not perform laparoscopy were evaluated. RESULTS: Sixty-one former residents (67%) responded to the questionnaire. Urologists were more likely to perform laparoscopic procedures if they had been trained during their residency (69%) than if they had no experience during residency (34%; p < 0.025). Intensity of laparoscopic experience in residency did not appear to correlate with ongoing practice, with 73% of residents having <15 cases during residency training continuing to perform laparoscopy compared with 67% of residents doing 15 to 80 laparoscopic cases. Urologists who had been trained in laparoscopy during residency cited the need for more training (47%) and inadequate case volume (47%) as reasons for not currently performing laparoscopy. Among those who had received residency training, the most common reasons given were inadequate case volume (61%) and increased operative time (57%). CONCLUSIONS: This survey suggests that laparoscopic procedures are more likely to be performed by physicians who have received training during residency. As the number of urologists who have been trained in laparoscopy during residency increases, shifts in practice patterns will continue to evolve, along with advances in urologic laparoscopy.

Humans↗
PubMed2002

Renal hypothermia achieved by retrograde intracavitary saline perfusion.

BACKGROUND AND PURPOSE: Hypothermia during vascular clamping protects the kidney from ischemia-induced nephron loss. Traditionally, cooling is achieved by packing the kidney in ice, which lowers the temperature of the rest of the surgical field as well, and the method cannot be used during laparoscopy. We evaluated the utility of a newly developed ureteral access system for circulating ice-cold saline. MATERIALS AND METHODS: Domestic pigs underwent retrograde endoscopic cooling through an access sheath without (N = 2) or with (N = 3) renal artery occlusion, traditional ice-slush cooling with renal artery occlusion (N = 3), or occlusion without hypothermia (N = 3). Five days later, the pigs were sacrificed and the kidneys and ureters examined histologically. RESULTS: Endoscopic cooling with renal artery occlusion and ice-slush cooling both produced renal hypothermia. The former produced medullary and cortical temperatures of 21.3 degrees C and 27.3 degrees C, respectively, and the latter medullary and cortical temperatures of 28.8 degrees C and 23.7 degrees C, respectively. Histologically, there were minimal changes in the first three groups, whereas venous congestion, multifocal chronic inflammation, and periarteriolar hemorrhage were seen after renal artery occlusion without hypothermia. CONCLUSION: Retrograde endoscopic renal hypothermia is effective and requires no novel equipment or special surgical skills. Clinical application has not yet been attempted.

Animals↗
PubMed2002

Bare naked baskets: ureteroscope deflection and flow characteristics with intact and disassembled ureteroscopic nitinol stone baskets.

PURPOSE: Lower pole renal access during flexible ureterorenoscopy is often limited by the active deflection capabilities of the ureteroscope. Deterioration in the deflection and flow capabilities of ureteroscopes occurs with the passage of instrumentation through the working channel. We performed in vitro evaluation of a novel technique using unsheathed nitinol baskets to minimize the deterioration in deflection and maximize the irrigant flow associated with instrument passage through the working channel during flexible ureterorenoscopy. MATERIALS AND METHODS: Alterations in the irrigant flow and active deflection of 4 ureteroscopes from different manufacturers were evaluated. Each ureteroscope was evaluated with an empty working channel, and then with sheathed and unsheathed 2.2, 3 and 3.2Fr (Cook Urological, Inc., Indianapolis, Indiana), 2.4 and 3Fr (Microvasive Urology, Natick, Massachusetts) nitinol baskets in the working channel. RESULTS: With all baskets tested and in all ureteroscopes the deterioration in active deflection and irrigant flow was improved with the unsheathed baskets. The disassembled basket within the working channel allowed an additional 15 to 20 degrees of active deflection. In addition, the disassembled basket allowed for a 2 to 30-fold increase in irrigant flow compared with an intact basket. CONCLUSIONS: The combination of improved deflection and irrigant flow with this technique may improve ureteroscopic access to lower pole renal calculi.

Alloys↗
PubMed2002

[Male sexual dysfunction with spinal cord injury and other neurologic diseases].

Male sexual function requires an intricate interplay between the man and his environment. Cognitive integration and physiological response to sexual stimulation is dependent on complex neurologic functions that may be impaired by central or peripheral neurologic disorders. This article reviews the normal neuroanatomy of sexual functioning in men, and the epidemiology, pathophysiology and management of sexual dysfunction in spinal cord injury, cerebrovascular accident, multiple sclerosis and Parkinson's disease.

Erectile Dysfunction↗