Using machine learning models to predict synchronous genitourinary cancers among gastrointestinal stromal tumor patients

Objectives

Gastrointestinal stromal tumors (GISTs) can occur synchronously with other neoplasms, including the genitourinary (GU) system. Machine learning (ML) may be a valuable tool in predicting synchronous GU tumors in GIST patients, and thus improving prognosis. This study aims to evaluate the use of ML algorithms to predict synchronous GU tumors among GIST patients in a specialist research center in Saudi Arabia.

Materials and Methods

We analyzed data from all patients with histopathologically confirmed GIST at our facility from 2003 to 2020. Patient files were reviewed for the presence of renal cell carcinoma, adrenal tumors, or other GU cancers. Three supervised ML algorithms were used: logistic regression, XGBoost Regressor, and random forests (RFs). A set of variables, including independent attributes, was entered into the models.

Results

A total of 170 patients were included in the study, with 58.8% (n = 100) being male. The median age was 57 (range: 9-91) years. The majority of GISTs were gastric (60%, n = 102) with a spindle cell histology. The most common stage at diagnosis was T2 (27.6%, n = 47) and N0 (20%, n = 34). Six patients (3.5%) had synchronous GU tumors. The RF model achieved the highest accuracy with 97.1%.

Conclusion

Our study suggests that the RF model is an effective tool for predicting synchronous GU tumors in GIST patients. Larger multicenter studies, utilizing more powerful algorithms such as deep learning and other artificial intelligence subsets, are necessary to further refine and improve these predictions.

A study of the histopathology of collagen fleece (TachoSil) patching of tunica albuginea in the rat penis and a literature review of penile graft materials in experimental animals

Background

A penile tunica defect may arise during surgery in patients with Peyronie's disease. Collagen fleece (TachoSil) has recently gained popularity in penile surgery to cover the tunica albuginea (TA) defect associated with clinical success. However, it is not known what the histological outcomes of these grafts are in the penis. We aimed to study the histopathology of the TachoSil graft in an experimental animal model for the regeneration of TA, inflammation, fibrosis, and the underlying cavernous tissue.

Methods

Six adult male Sprague Dawley rats were used. The penis was degloved through a circumferential subcoronal incision. A longitudinal 1 mm × 10 mm defect was created at the base of the lateral aspect of the penis. A TachoSil patch (Takeda, Japan) was applied to the defect. The penile skin covering was then restored. At 2 months, the rat penis was excised and examined with hematoxylin, eosin, and trichrome stains. We conducted a literature review of penile grafts in animals for comparison.

Results

Rats weighed 369.2 gm (standard deviation: 31.5). At 2 months, all rats showed normal-looking penis with complete healing, no scaring, tethering, or gross inflammatory features. Histopathology of the patch site showed fibrosis, chronic inflammation, and foreign body giant cell reaction. There was no generation of a new TA, or new vascularity. No inflammatory or pathological reaction affected the underlying corpus cavernous tissue. One rat died on the 6th postoperative day. Postmortem showed massive multiorgan hemorrhage consistent with disseminated intravascular coagulopathy (DIC). Unlike some other reported grafts, there is no TA regeneration.

Conclusions

TachoSil patching of penile TA defect forms a distinctive barrier against inflammation, protecting the underlying corpus cavernosum. However, no regeneration of the tunica defect is observed at 2 months. DIC is a potential complication of systemic absorption of TachoSil.

A Staghorn Calcium Phosphate Stone in a Child With Sanjad-Sakati Syndrome: An Iatrogenic Manifestation?

Sanjad-Sakati syndrome (SSS) is an autosomal recessive genetic condition, with the first report discussing this condition presented in Saudi Arabia. This case report describes an iatrogenic stone as a result of hypocalcemia overtreatment, along with its subsequent management procedure. The current literature concerning the iatrogenic stone occurrence and the operative outcome of percutaneous nephrolithotomy in individuals with SS is scarce, warranting further investigation.

A Primary Urothelial Carcinoma Presenting as a Mid-Bulbar Urethral Stricture in a 30-Year-Old Male

The bulbar urethra is the most common site of anterior urethral strictures. In this case report, we present a 30-year-old male who was referred to us as a case of mid-bulbar urethral stricture. Urethroplasty was booked and a papillary lesion was found on routine diagnostic cystoscopy. An open biopsy was taken which showed invasive high-grade papillary urothelial carcinoma with squamous differentiation. This case is rare in terms of a young age of incidence, a lack of risk factors, an absence of suspicious symptoms, and a short duration of signs and symptoms. Urologists should consider workup for malignancy even in young patients who present with an idiopathic urethral stricture and a short duration of symptoms.

Operative outcomes of robotic partial nephrectomy. A report of the first 101 cases from a single center in Saudi Arabia

OBJECTIVES

To report robotic partial nephrectomy (RPN) outcomes from a single tertiary hospital in Saudi Arabia. Methods: We retrospectively reviewed consecutive cases of patients undergoing RPN at King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of  Saudi Arabia, between January 2008 and January 2018. The study reports patient's demographics, tumor characteristics, operative details, and perioperative outcomes, using descriptive statistics of median and range values. Results: One hundred and one patients underwent RPN during the study period. Average tumor size was 3 (1.3-6.4) cm and average radius exophytic nearness anterior/posterior location (RENAL) score was 6 (4-10). Perioperative parameters were blood loss 200 (5-1500) ml and warm ischemia time 17 (8-40) minutes, excluding off-clamp surgery in 12 (11.9%); operative time was 166 (66-381) minutes. Conversion to open partial nephrectomy occurred in 9 (8.9%) patients, major complications in 3 (3%) patients, positive surgical margins in 5 (5%) patients, and the hospital stay was 4 (2-14) days. A total of 73 (73%) patients achieved a trifecta of freedom from any complication, negative surgical margins, and ischemia time ≤25 minutes. Study limitations included the retrospective design and small cohort size. Conclusions: The initial experience of robotic partial nephrectomy was associated with a surgical outcome comparable to that reported by higher-volume centers.

Serum testosterone levels and other determinants of sperm retrieval in microdissection testicular sperm extraction

Background

Microdissection testicular sperm extraction (microTESE) has become the standard of care for sperm retrieval in non-obstructive azoospermia (NOA) patients. Understanding the significant determinants of microTESE outcomes may result in improvements in sperm retrieval rates and provide better-informed clinical decisions.

Methods

This is a clinical retrospective study conducted through chart review of 421 NOA patients who underwent microTESE between August 2009 and July 2015 in a tertiary-care referral hospital. Clinical, biochemical and histopathological characteristics were collected. Normal serum testosterone level was defined as testosterone >9.9 nmol/L. Multiple logistic regression was used to identify determinants of microTESE in the studied population. A P<0.05 was considered significant.

Results

Sperms were successfully retrieved in 39.4% of cases. The average testosterone level was 11.51±7.40 and 11.67±6.42 in patients with successful and unsuccessful microTESE, respectively (P=0.820). No significant association was found between serum testosterone level and sperm motility and amount. Of all variables, histological subtype remained to be the most significant determinant of microTESE outcomes in the examined population, with hypospermatogenesis having over a 3-fold higher odd of successful microTESE than sertoli-cell only.

Conclusions

Serum testosterone level appears to have no significant association with microTESE outcomes in NOA. The underlying histological pattern is a significant determinant of the procedure’s success.

Hypospadias repair during adulthood: Case series

Purpose

We report our complications and success rate in adult hypospadias repair.

Patients and Methods

This was a retrospective study of patients aged ≥17 years who underwent hypospadias repair during 2006-2014. We analyzed two groups, one with primary repair and the other that had secondary repair after failed childhood hypospadias surgery. Outcome was compared between the two groups and among different surgical procedures. Descriptive statistics and Fisher's exact test were used and significance level was set at P < 0.05.

Results

Forty patients were included, of which 26 presented for a secondary repair and 14 for primary repair. The meatus was distal in 15 patients, mid-penile in 16, and penoscrotal in 9. The median age of patients at the time of surgery was 21 years (standard deviation [SD] =4, range 17-30). The median follow-up period was 37 months (SD = 8, range 5-75). In the primary repair group, the success rate was 71% (10/14), whereas in the secondary repair group, the success rate was 55% (14/26). The overall complication rate was 60%. Following a subsequent repair, the overall success rate reached 95% (38/40). There was no significant difference in success or complications between patients who presented with primary or secondary hypospadias or between methods of repair.

Conclusion

Delayed hypospadias repair in adults is associated with a high success rate of 95% with no difference between primary and secondary repair. Secondary repair however may require more than one procedure most of the time.

Penile autotransplantation in rats: An animal model

CONTEXT

Penile allotransplantation might be a viable option for patients who need penile reconstruction.

AIMS

A successful autotransplantation rat model is the first step toward proceeding for allotransplantation. We herein evaluate autotransplantation following transaction of the rat penis just distal to the urethral bulb.

SETTINGS AND DESIGN

Experimental animal study.

MATERIALS AND METHODS

Five Sprague-Dawely rats weighing 520 g (SD 19) were used. Utilizing a magnification of 6-40, transection and immediate anastomosis of the tunica albuginea, urethra, dorsal vein and nerves were carried out. Vesicostomy was made to divert urine. The glandular skin was sutured to the perineum and the abdominal wall was closed in layers.

STATISTICAL ANALYSIS USED

Descriptive statistics.

RESULTS

Average surgery time was 8 h. The first two rats had no vesicostomy and died in the first postoperative day from retention. Three rats tolerated well the procedure and survived to the end point. One rat was sacrificed at day 10 and histopathology showed 30-50% necrosis of the implanted penis. Another rat was sacrificed at day 20 and showed normal cavernous tissue. The fifth rat was sacrificed 3 months postoperatively and showed evidence of moderate corporal fibrosis. Urethral fistula and necrosis of corpus spongiosum, dorsal nerve necrosis and dorsal vein occurred in all animals.

CONCLUSIONS

Penile autotransplantation in rats is feasible and provides the basis for evaluation of the corpora cavernosa in an allotransplantation model. Long-term urethral continuity and dorsal neurovascular bundle survival in this model is difficult to establish.

Long-term outcome of genital reconstruction of Middle Eastern women with congenital adrenal hyperplasia

Objectives:

There is a paucity of data on the long-term outcome of genital reconstruction of female children with congenital adrenal hyperplasia (CAH) as they become adult women. We report on the surgical outcome general condition and marriage status.

Materials and Methods:

We reviewed the medical records of women 20 years or older with CAH who had genital reconstruction. We interviewed married patients utilizing the female sexual function index (FSFI-6) questionnaire and compared them to age-matched controls.

Results:

We identified 43 women with CAH with a median age of 24.2 ± 3.9 years and a median follow-up of 23.4 ± 4.6 years. Salt wasting and the severity of virilization affected most patients, parents were commonly cousins, children were reared as boys for a protracted period and surgical reconstruction was usually complex. Only five women had married. Compared with single women, married women had significantly more frequent normal menses, emergency hospital admissions and number of repeated reconstructive surgery. There was no significant difference in FSFI score between patients and controls. Four women conceived and three gave birth to one healthy child. There was no significant difference in the number of children between patients and controls.

Conclusions:

CAH has a significant impact on adult women in our region. Most of the patients remain single. Few women get married and these are able to lead a nearly normal sexual life and give birth to healthy children.

Isolated renal hydatid disease in a non-endemic country: a single centre experience

Objective: Isolated renal hydatid disease (HD) is rare in nonendemic countries. Clinical and radiological suspicion warrants appropriate serological tests, preoperative treatment and intra-operative precautions. We present a tertiary care centre experience of isolated renal HD in a non-endemic country.Methods: We reviewed the medical records of patients with HD treated in the past 20 years. We identified patients with the definitive diagnosis of isolated renal HD and described their management.Results: Of the 119 cases with HD, 6 were found to have isolated renal involvement (5%). Their median age was 46.5 (28-70) years. Five patients presented with flank pain and 1 had an incidentally discovered renal mass. Radiologic investigations raised the suspicionof possible HD in 4 cases, while 2 cases were diagnosed as renal tumours. Computerized tomography showed complex renal cyst in 4, solid renal mass with heterogonous enhancement in 2 and calcification in 5. Eosinophilia and indirect hemagglutinationtest (IHA) were positive in 3 of the 4 suspected cases. Three cases were treated as renal tumours, while 3 were managed as HD. Four cases had total nephrectomy and 2 had partial nephrectomy. Histopathology revealed that all cases had renal HD. Patients were followed for a median of 7.3 (0.4-11.3) years with no evidence of recurrence.Conclusions: Isolated renal HD is a challenging preoperative diagnosis in non-endemic countries. The definitive diagnosis is only possible by histopathology. Retrospectively, HD mimicked renal tumours in half the cases and should be considered in the differential diagnosis of renal space occupying lesions.

Isolated renal hydatid disease in a non-endemic country: a single centre experience

OBJECTIVE

Isolated renal hydatid disease (HD) is rare in non-endemic countries. Clinical and radiological suspicion warrants appropriate serological tests, preoperative treatment and intra-operative precautions. We present a tertiary care centre experience of isolated renal HD in a non-endemic country.

METHODS

We reviewed the medical records of patients with HD treated in the past 20 years. We identified patients with the definitive diagnosis of isolated renal HD and described their management.

RESULTS

Of the 119 cases with HD, 6 were found to have isolated renal involvement (5%). Their median age was 46.5 (28-70) years. Five patients presented with flank pain and 1 had an incidentally discovered renal mass. Radiologic investigations raised the suspicion of possible HD in 4 cases, while 2 cases were diagnosed as renal tumours. Computerized tomography showed complex renal cyst in 4, solid renal mass with heterogonous enhancement in 2 and calcification in 5. Eosinophilia and indirect hemagglutination test (IHA) were positive in 3 of the 4 suspected cases. Three cases were treated as renal tumours, while 3 were managed as HD. Four cases had total nephrectomy and 2 had partial nephrectomy. Histopathology revealed that all cases had renal HD. Patients were followed for a median of 7.3 (0.4-11.3) years with no evidence of recurrence.

CONCLUSIONS

Isolated renal HD is a challenging preoperative diagnosis in non-endemic countries. The definitive diagnosis is only possible by histopathology. Retrospectively, HD mimicked renal tumours in half the cases and should be considered in the differential diagnosis of renal space occupying lesions.

Changing trends in presentation, diagnosis and management of renal angiomyolipoma: comparison of sporadic and tuberous sclerosis complex-associated forms

OBJECTIVES

To evaluate the changing management of sporadic renal angiomyolipoma and renal angiomyolipoma associated with the tuberous sclerosis complex (TSC) during the past 16 years.

METHODS

We retrospectively reviewed the charts of 60 patients with angiomyolipoma seen at our institutions.

RESULTS

The median age at presentation was 45 years (range 7-78). The presentation was pain in 30 patients and hematuria in 13; it was incidentally discovered in 17 patients. Of the 60 patients, 43 were females. TSC was present in 14 patients. The median tumor size was 4 cm (range 0.3-40, mean 6.5 +/- 1.1). Of the 60 patients, 31 were followed up expectantly. Surgery or intervention was needed for 29 patients to control hemorrhage or relieve pain or because of the suspicion of malignancy. Of these 29 patients, 12 underwent nephrectomy, 11 partial nephrectomy, and 6 embolization. The patients treated for hemorrhage had a median tumor diameter of 11 cm (range 2-21). Patients were followed up for a mean of 39.3 +/- 5.4 months. The lesions grew an average of 4.7 +/- 3.4 cm for TSC tumors and 0.6 +/- 0.2 cm for sporadic angiomyolipoma tumors. None of the patients developed renal impairment. Patients with TSC presented at a younger age, had larger and bilateral lesions, and were more symptomatic during follow-up. In the past 6 years, a significant trend was seen toward finding tumors in asymptomatic patients and toward the use of conservative or interventional (embolization) treatment.

CONCLUSIONS

Renal angiomyolipoma has a slow growth rate. The preservation of renal function was noted in all our patients. A recent shift was noted toward finding smaller tumors in asymptomatic patients and the use of conservative and interventional treatment.

Robotic augmentation enterocystoplasty

Augmentation enterocystoplasty is an established procedure performed to increase bladder capacity and reduce intravesical pressure in patients with neurogenic bladder. Although the open surgical procedure remains the most widely accepted technique, laparoscopic enterocystoplasty has been described. As an extension of the minimally invasive approach, we describe a technique for robotic augmentation enterocystoplasty with a completely intracorporeal method. To our knowledge, this is the first report of such a technique.

Pheochromocytoma in children and adolescents: a clinical spectrum

PURPOSE

The purpose of the study was to identify the spectrum of disease characteristics of pheochromocytoma in children.

METHODS

Records of 21 consecutive children diagnosed with pheochromocytoma were reviewed. Patients' age, sex, presentation, associated conditions, diagnostic and imaging modalities used, preoperative preparation, operative details, outcome, and follow-up were recorded.

RESULTS

The study included 21 children. Patients were diagnosed clinically and confirmed by biochemical tests. Tumors were localized by imaging studies and all were confirmed pathologically. Patients included 17 with adrenal and 4 with extra-adrenal tumors including 1 in the urinary bladder. Seventeen had sporadic and 4 had familial pheochromocytoma. Associated manifestations were the predominant features in 1 of the 4 patients with familial pheochromocytoma. The patient with bladder pheochromocytoma presented with gross hematuria. Hypertension and visual disturbances were prominent findings in the other patients with sporadic form. Two patients (1 sporadic and 1 familial) had malignant pheochromocytoma. One patient with benign pheochromocytoma had multiple recurrences in chromaffin-containing sites. All patients were treated surgically. Seventeen patients were treated preoperatively with alpha-adrenergic blockade. Two patients continued to have significant visual disturbances. One patient with malignant pheochromocytoma died of the disease, and 1 with recurrent pheochromocytoma had neurologic consequences.

CONCLUSIONS

Pheochromocytoma in children has unique characteristics. To our knowledge, this series is one of the largest reports of adrenal pheochromocytoma in children. It also reflects the spectrum of pheochromocytoma in this age group.

Crural Tunica Albuginea Autograft for Corporoplasty: An Experimental Animal Study of Hemodynamic, Histopathological, and Molecular Effects in the Long Term

INTRODUCTION

Correction of penile deformity caused by Peyronie's disease by a variety of grafts varies in success. A long-term follow-up shows a significant number of graft scarring and erectile dysfunction. The clinical success of autologous crural tunica albuginea graft (TAG) has not resulted in wide application.

AIM

To identify in healthy baboons the limitations and merits of autologous crural TAG over 1 year in a way difficult to pursue in humans.

METHODS

Under general anesthesia, eight sexually active adult baboons underwent pharmacological cavernosometry (CM) and cavernosography. TAG from crus was implanted in the distal penile shaft. After 6 months, six animals were reevaluated and two were sacrificed, and the penises were excised. After 1 year, the remaining six animals were evaluated and sacrificed. The TAG and underlying corpus cavernosum (CC) were examined histologically and by Western blot analysis for nitric oxide synthase (NOS), neuronal (nNOS), endothelial (eNOS) and inducible (iNOS) isoforms, and transforming growth factor-beta1 (TGF-beta1).

MAIN OUTCOME MEASURES

Sexual activity, CM, cavernosography, histopathology, and Western blot analysis.

RESULTS

All animals resumed normal sexual activity 1 month postsurgery. Cavernous pressure was comparable before, at 6 months, and 1 year after surgery. A cavernovenous insufficiency developed in four animals at 6 months, and ceased in two at 1 year. Penile angulation (<20 degrees) was seen in three animals at 6 months, and an additional two at 1 year. Histologically, TAG was indistinguishable from the adjacent tunica with no fibrosis. In CC, iNOS and nNOS decreased at 1 year, whereas there was no change in TGF-beta1 levels. In TAG, there was no significant change in TGF-beta1 and eNOS levels, but there was a significant decrease in iNOS at 1 year.

CONCLUSION

Autologous free TAG is associated with normal sexual activity, minimal hemodynamic changes, excellent histological outcome, and no rise in iNOS or TGF-beta1. However, cavernovenous insufficiency, mild penile angulation, and decreased nNOS persisted at 1 year.

Outcome of Penile Cancer in Circumcised Men

PURPOSE

We previously reported on a group of patients with post-circumcision carcinoma of the penis. We now study the long-term outcome of these patients.

MATERIALS AND METHODS

We retrospectively reviewed the available charts of 22 patients presenting between October 1979 and May 2000.

RESULTS

Of 22 patients 18 underwent ritual circumcision with extensive scar development. Median age at diagnosis was 62.4 years. The penile lesion was dorsal and proximally located in 15 patients. Median delay before diagnosis was 12 months. Clinically 14 patients had stage T1-T2 disease, with 13 having no lymph node involvement and none with distant metastasis, 8 patients had stage T3-T4 disease. A total of 15 patients were treated surgically with total penectomy (10) or conservative local excision (5), inguinal lymph node dissection (9) and subsequent penile reconstruction (3). Pathological staging in 15 patients revealed 10 patients with stage T1 and in 8 patients with lymph node dissection none had nodal metastasis. Histopathological classification was 20 squamous cell carcinoma, 1 sarcoma and 1 verrucous carcinoma. Six patients refused surgery and 1 was referred for palliation. Median followup was 14.5 months and median survival was 14.5 months. The 3-year survival was 42% for stage T1-T2 and 13% for T3-T4 (p = 0.0052). Median survival for the surgical group was 34 months whereas for nonsurgical group was 3 months (p = 0.0016). Recurrence-free survival in the surgical group was 50%.

CONCLUSIONS

Penile carcinoma in circumcised men is a distinct disease commonly following nonclassic vigorous circumcision. Delayed diagnosis and deferring surgical treatment are associated with increased mortality.

Prevalence of erectile dysfunction and its correlates in Egypt: a community-based study

We evaluated the prevalence of erectile dysfunction (ED) in a cross-sectional community-based random sample of Egyptian men. ED was correlated with the socioeconomic status, risk factors and quality of life. Married men in Ismailia province were interviewed at home. Data were processed for 805 men with mean age of 43.58 y (s.d. 11.03). There is a fair correlation between ED and increasing age (< or = 0.001). Males with complete ED comprised 13.2% of the sample, 26% of men in their 50s, 49% of men in their 60s and 52% of those 70 y or older. The state of better erection correlated fairly with sexual desire and sexual satisfaction (< or = 0.01). ED was associated with living in rural areas and lower socioeconomic level (< or = 0.01), with smoking, diabetes, heart disease, hypertension, liver disease, arthritis, peptic ulcer and renal disease (< or = 0.05). ED was negatively associated with good quality of life (< or = 0.001). These results indicate that ED is a common problem among married Egyptian men.

New insights into the role of endothelin-1 in radiation-associated impotence

The objectives of this work were to: (1) Determine if prostate and penile tissue levels of endothelin-1 (ET-1) are increased in a rat following pelvic irradiation. (2) Determine if an ETa receptor antagonist (BQ-123) potentiates erectile function in these irradiated animals. Rats were divided into three study groups: control, 1000 cGy and 2000 cGy. The experimental groups received a single dose of radiation to the pelvic region. A time course was established to measure the effects of irradiation on prostate and penile tissue levels of endothelin-1 (ET-1)-like immunoreactivity. The effect of intracavernous injection of BQ-123 (25 microg/30 microl) was evaluated by measuring intracavernous pressure (ICP) following cavernous nerve electrical field stimulation. In the 2000 cGy group, a significant rise in ET-1-like immunoreactivity tissue levels was observed at 20 days. A significant decrease in ICP was recorded in the 1000 and 2000 cGy irradiated rats compared to the control group. Only the 2000 cGy group had a significant improvement in erectile function following BQ-123 administration. A significant improvement was observed 20 min post-administration, lasted 90 min, and was back to pre-administered levels at 120 min. The conclusion made was that radiation-induced impotence in irradiated rats is associated with an increased production of ET-1. Preliminary results are suggestive that ETa receptor antagonist may be of use to reverse such radiation-induced impotence in these irradiated animals.

Neuronal and endothelial nitric oxide synthase isoforms: quantification of protein and mRNA in the normal rat penis

Nitric oxide synthase (NOS) is an important enzyme for erection. We evaluated the content of neuronal (nNOS) and endothelial (eNOS) isoforms and their mRNA in the penis and major pelvic ganglion (MPG) of adult male rats by Western and Northern blot analysis. The cerebellum was evaluated as a control. nNOS protein and its mRNA were detected in abundance in the MPG, cerebellum, pelvic urethra and within the crura of the penis. In contrast, the penile urethra, neurovascular bundle and the shaft of penis contained smaller amounts of this protein. eNOS protein was most abundant in the penile and pelvic parts of the urethra, whereas a moderate level was found in the penile shaft, crura, neurovascular bundle, MPG and cerebellum. Similarly eNOS mRNA was abundant in the penile and pelvic parts of the urethra, MPG and cerebellum. Penile shaft, crura and neurovascular bundle showed moderate amounts of eNOS mRNA. In conclusion, nNOS and its mRNA are most abundant in the MPG and crura of penis whereas eNOS is most abundant in the urethra and to a lesser extent present in the penis. Importantly eNOS protein and mRNA were demonstrated in the MPG, where eNOS function has to be studied.

Reduction of ventral prostate weight by finasteride is associated with suppression of insulin-like growth factor I (IGF-I) and IGF-I receptor genes and with an increase in IGF binding protein 3

Finasteride, a competitive and specific inhibitor of 5alpha-reductase, is widely used in the treatment of symptomatic benign prostatic hyperplasia. We demonstrate here that finasteride, when administered in an in vivo experimental system, caused ventral prostate regression. Intraprostatic dihydrotestosterone levels decreased, whereas testosterone levels increased in a dose-dependent manner following finasteride treatment. Finasteride also inhibited the expression of insulin-like growth factor (IGF)-I and IGF-I receptor genes in the ventral prostate. Finasteride significantly increased IGF binding protein-3 and slightly decreased IGF binding protein-2, -4, and -5 gene expression. Because IGFs are potent mitogens for prostate epithelial cells, this newly described activity of finasteride may contribute to its antiproliferative properties, particularly with regard to the inhibition of prostate growth seen clinically and in animal models.

Evaluation of a no-needle penile injector: a preliminary study evaluating tissue penetration and its hemodynamic consequences in the rat

OBJECTIVES

Intracavernous needle injection is an effective delivery method for pharmacotherapy of erectile dysfunction. Needle phobia, pain, and concern about local tissue injury have stimulated the search for new, less invasive means of inducing penile erection. In this preliminary communication, we evaluate a jet injector as an alternative to needle injection for intracavernous delivery of vasoactive drugs.

METHODS

Jet injection was evaluated in three groups of rats receiving either India ink, saline, or papaverine into the penis. The ability of the jet injection to penetrate through the tunica albuginea and deliver liquid to the corpora cavernosa smooth muscle was assessed by the degree of staining within the corpus cavernosum (ink group), histologic change (saline group), and rise in intracavernous pressure (papaverine group). Erectile capacity following cavernous nerve electric stimulation was compared before and 1 hour after injection of saline or papaverine.

RESULTS

Ink traversed the skin and tunica albuginea with extensive deposition noted within the cavernous spaces. Varying degree of subcutaneous hemorrhage were seen with saline jet injection; however, the corpus cavernous smooth muscles showed no evidence of injury. Jet injection of papaverine 3250 micrograms significantly increased cavernous pressure (39.4 +/- 4.6 cm H2O) compared with saline injection (2.8 +/- 1.3 cm H2O).

CONCLUSIONS

We conclude that acute jet injection is an effective method for intracavernous delivery of drugs. Long-term effects should be evaluated prior to clinical use.