Amirali Hassanzadeh Salmasi

miR-21: an androgen receptor-regulated microRNA that promotes hormone-dependent and hormone-independent prostate cancer growth.

Androgen receptor (AR)-mediated oncogenic pathways have not been fully elucidated. In this study, we used high-throughput microarray analysis on two AR-positive prostate cancer (CaP) cell lines to identify 16 AR-responsive microRNAs (miRNA). We focused on miR-21 because of its previously reported oncogenic activity in other cancers. We show androgen-induced AR binding to the defined miR-21 promoter, miPPR-21, suggesting direct transcriptional regulation. Inhibition of miR-21 diminished androgen-induced CaP cell proliferation, providing new evidence that miRNAs can contribute to androgen-driven cell growth. Elevated expression of miR-21 enhanced CaP tumor growth in vivo and, surprisingly, was sufficient for androgen-dependent tumors to overcome castration-mediated growth arrest. Thus, elevated miR-21 expression alone is sufficient to impart castration resistance. Moreover, quantitative reverse transcription-PCR analysis revealed elevated miR-21 expression in CaP when compared with adjacent normal tissue. These results suggest that miR-21 may contribute to CaP pathogenesis.

Safety of Robot-Assisted Radical Prostatectomy with Pneumoperitoneum of 20 mm Hg: A Study of 751 Patients

BACKGROUND AND PURPOSE Early studies describing robot-assisted radical prostatectomy (RARP) reported the use of pneumoperitoneum at a pressure of 15 mm Hg. While higher insufflation pressures (20 mm Hg) may reduce venous oozing and improve visualization, the safety of this method has not been confirmed. This study evaluates the short-term perioperative outcomes of patients undergoing RARP with insufflation pressures of 20 mm Hg. PATIENTS AND METHODS A single-surgeon, prospectively maintained database of patients undergoing RARP was retrospectively analyzed. Patients who underwent RARP with a pneumoperitoneum pressure of 15 and 20 mm Hg for the entire procedure were analyzed. Preoperative and postoperative hemoglobin levels and estimated glomerular filtration rate (eGFR) were compared. Complications, operative time, and estimated blood loss were also examined. RESULTS The number of patients in the experimental (20 mm Hg) and control (15 mm Hg) groups were 550 and 201, respectively. The groups were well matched with respect to age and operative time. The experimental group had a significantly smaller decrease in mean hemoglobin levels after surgery (-1.18 vs-2.13 mg/dL, P<0.0001). There was no significant difference in the eGFR on the first day after surgery (postoperative day [POD]1) (88.4 vs 85.0 mL/min/1.73m(2), P=0.11) or in the change in eGFR from preoperative to POD1 levels (-0.49 vs 1.54 mL/min/1.73m(2), P=0.18). The complication rate in the experimental group was 8.55% vs 8.46% in the control group. CONCLUSION Pneumoperitoneum using a pressure of 20 mm Hg for RARP is safe and has no significant short-term effects on renal function and hemoglobin. Increased insufflation pressure was not associated with a higher complication rate.

Transurethral Autologous Myoblast Injection for Treatment of Urinary Incontinence in Children With Classic Bladder Exstrophy

PURPOSE The application of autologous myoblasts is an area of active research that may represent an improved alternative for the treatment of urinary incontinence. In this study we investigated the effectiveness of autologous myoblast injection for the treatment of urinary incontinence in children with classic bladder exstrophy. MATERIALS AND METHODS Seven boys and 1 girl with persistent urinary incontinence were entered in the study. All children had undergone staged bladder repair and bladder neck reconstruction, and 5 patients had received 1 to 3 transurethral injections of bulking agent. Autologous myoblasts were isolated from abdominal muscle biopsy and cultured before endourethral injection. After the procedure patients underwent pelvic floor electrical stimulation and continued pelvic floor exercises that had been started at least 1 year before injection. The clinical outcomes (based on a 24-hour voiding diary), and cystometric and urodynamic studies were evaluated. Followup ranged from 12 to 18 months (average 15.3). RESULTS There was a significant, time dependent improvement in urinary continence. At final followup all 7 boys (88% of patients) were socially dry (daytime dryness more than 3 hours), including 3 (38%) who were completely dry. Urodynamic studies revealed an increase in mean bladder capacity (p <0.001), detrusor leak point pressure (p <0.001) and average maximum urinary flow (p <0.01). All 7 boys (vs only 2 patients preoperatively) achieved normal voiding with demonstrable voiding detrusor contraction in the presence of a compliant stable bladder (p <0.05). CONCLUSIONS Our results suggest that transurethral autologous myoblast injection is a valid option for the treatment of structural urinary incontinence in children with classic bladder exstrophy. However, favorable preoperative urodynamic profiles and postoperative pelvic floor electrical stimulation may have contributed to the outcome in this series.

Salutary Effects of N-Acetylcysteine on Apoptotic Damage in a Rat Model of Testicular Torsion

Introduction: Numerous studies performed in recent years have shown protective effects of N-acetylcysteine (NAC) on cardiac and renal tissue damage following ischemia/reperfusion injury. We assessed the effectiveness of systemic administration of NAC, at a therapeutic dose, in a rat model of a 1-hour 720-degree testicular torsion/detorsion. Materials and Methods: Sprague-Dawley rats were divided into five groups, 14 animals in each: group 1 animals underwent sham operation as the control group; group 2 rats underwent torsion/detorsion and received saline injection, and the animals in groups 3, 4, and 5 received intraperitoneal injections of 150 mg/kg NAC 30 min before torsion, after torsion, and after detorsion, respectively. Markers of oxidative stress as well as germ cell apoptosis indices were assessed 4 and 24 h after detorsion, respectively. Results: The apoptosis indices were significantly higher in group 2 as compared with the control group. Four hours after detorsion, the testicular level of lipid peroxidation was significantly increased, and antioxidant enzyme activities were significantly decreased in group 2 as compared with the controls. Administration of NAC either 30 min before or after torsion (groups 3 and 4) significantly improved the germ cell apoptosis indices and oxidant/antioxidant balance. Administration of NAC after detorsion had no significant effect on biochemical markers or germ cell apoptosis. Conclusion: Administration of NAC prior to torsion or detorsion, but not after detorsion, induces protective effects against ischemia/reperfusion injury in a rat model of testicular torsion.

Oligodendroglial and Pan-neural Crest Expression of Cre Recombinase Directed by Sox10 Enhancer

Utilizing a recently identified Sox10 distal enhancer directing Cre expression, we report S4F:Cre, a transgenic mouse line capable of inducing recombination in oligodendroglia and all examined neural crest derived tissues. Assayed using R26R:LacZ reporter mice expression was detected in neural crest derived tissues including the forming facial skeleton, dorsal root ganglia, sympathetic ganglia, enteric nervous system, aortae, and melanoblasts, consistent with Sox10 expression. LacZ reporter expression was also detected in non‐neural crest derived tissues including the oligodendrocytes and the ventral neural tube. This line provides appreciable differences in Cre expression pattern from other transgenic mouse lines that mark neural crest populations, including additional populations defined by the expression of other SoxE proteins. The S4F:Cre transgenic line will thus serve as a powerful tool for lineage tracing, gene function characterization, and genome manipulation in these populations. genesis 47:765–770, 2009.

Molecular Effects of Genistein on Male Urethral Development

PURPOSE The increasing incidence of hypospadias is partly attributed to increased gestational exposure to endocrine disruptors. We investigated the effects of genistein, the primary phytoestrogen in soy, on the molecular program of male urethral development. MATERIALS AND METHODS Female mice were fed diets supplemented with genistein (500 mg/kg diet) or control diets before breeding and throughout gestation. Urethras from embryonic day 17.5 male fetuses were harvested, and RNA was prepared, amplified, labeled and hybridized on whole genome microarrays. Data were analyzed using packages from the R/Bioconductor project. Immunohistochemical analysis and immunoblotting were used to confirm the activity of MAPK and the presence of Ntrk1 and Ntrk2 during urethral development. RESULTS Gestational exposure to genistein altered the urethral expression of 277 genes (p <0.008). Among the most affected were hormonally regulated genes, including IGFBP-1, Kap and Rhox5. Differentially expressed genes were grouped into functional pathways of cell proliferation, adhesion, apoptosis and tube morphogenesis (p <0.0001), and were enriched for members of the MAPK (p <0.00001) and TGF-β (p <0.01) signaling cascades. Differentially expressed genes preferentially contained ELK1, Myc/Max, FOXO, HOX and ER control elements. The MAPK pathway was active, and its upstream genistein affected tyrosine kinase receptors Ntrk1 and Ntrk2 were present in the developing male urethra. CONCLUSIONS Gestational exposure to genistein contributes to hypospadias by altering pathways of tissue morphogenesis, cell proliferation and cell survival. In particular, genes in the MAPK and TGF-β signaling pathways and those controlled by FOXO, HOX and ER transcription factors are disrupted.

Bladder Neck Transection for Intractable Pediatric Urinary Incontinence

PURPOSE We report the indications, technique and outcome of a large series of children who underwent bladder neck transection for intractable urinary incontinence. MATERIALS AND METHODS We retrospectively reviewed demographics, operative details, complications and outcomes of 76 patients (47 males, 29 females) who underwent bladder neck closure at our institution between 1996 and 2006. Mean patient age at the time of the procedure was 12 years, 10 months. The most common diagnosis was bladder exstrophy. Of the patients 31 had undergone prior bladder neck reconstruction (30) or sling repair (1). All patients underwent concomitant augmentation and creation of a catheterizable stoma. RESULTS A total of 50 patients had more than 12 months of followup (mean 44, range 12 to 128). Continence was achieved initially in 86% of the patients (43 of 50). Of the 7 primary failures 2 leaked via the urethra and 5 via the stoma. Six of these patients achieved dryness with revision, for a final continence rate of 98%. A single renal unit suffered significant loss of function during this period. New, nonobstructive hydronephrosis developed in 8 additional renal units. Stones developed in 30% of the patients. There were no spontaneous bladder ruptures. CONCLUSIONS Bladder neck transection in combination with enterocystoplasty and creation of a continent catheterizable stoma is an effective approach to incontinent cases with severely damaged bladder outlets and poor quality bladders in which other reconstructive approaches either have failed or are deemed likely to fail. Specific concerns regarding the risk of poor renal outcomes and perforation seem unwarranted at present.

Dose-dependent modulation of systemic lipid peroxidation and activity of anti-oxidant enzymes by vitamin E in the rat

Abstract The objective of this work was to examine the time-dependent pro-oxidant versus antioxidant effect of various doses of vitamin E used commonly in experimental studies. Erythrocyte activity of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and plasma lipid peroxidation levels were investigated following biweekly intramuscular administration of 100, 300 and 600 mg/kg of vitamin E at a baseline time point, and additionally at 2, 4 and 6 weeks after initiating treatment. Vitamin E had an antioxidant effect when administered at low doses over short time periods, and increased the activity of antioxidant enzymes. At higher doses and over longer time periods, it increased the level of lipid peroxidation, and attenuated the activity of antioxidant enzymes. These results suggest that time-dependent variations in vitamin E effects should be considered in design and interpretation of experimental antioxidant studies, as well as during clinical trials.

ATP-SENSITIVE POTASSIUM CHANNELS MEDIATE THE ANTI-ISCHEMIC PROPERTIES OF ISCHEMIC AND PHARMACOLOGIC PRECONDITIONING IN RAT RANDOM-PATTERN SKIN FLAP

Ischemic preconditioning (IPC) and pharmacologic preconditioning by morphine and adenosine may significantly decrease the amount of necrosis in rat random pattern skin flaps. We examined the role of ATP-sensitive potassium channels (KATP channels) in mediating these protective phenomenon by using glibenclamide a nonspecific blocker of these channels. We also investigated whether administration of diazoxide an opener of the KATP channels could mimic the same protective effect. Ninety male Sprague-Dawley rats were randomly divided into either control or treatment groups (n = 6 each). Bipedicled dorsal skin flaps (2 × 8 cm) were elevated at the midline. In pharmacologic preconditioning groups, 1 mL of morphine (5 mg/flap), adenosine (0.5 mg/flap), or different doses of diazoxide (0.5, 1, 5, and 15 mg/flap) were administered locally in the cranial half of the flap, respectively. One milliliter of saline was locally injected in the control group. In the IPC group, 1 hour after local saline injection the cranial pedicle was clamped for 20 minutes, and then 40 minutes’ reperfusion was performed. In another experiment, 0.3 mg/kg of glibenclamide was injected intraperitoneally 30 minutes before local administration of saline or drug in ischemic or pharmacologic preconditioning groups. Regardless of the group, all flaps were cut at the cranial side 2 hours after elevation and were sutured back. Flap survival area was evaluated on the seventh postoperative day. IPC and pharmacologic preconditioning with morphine, adenosine, and diazoxide (in higher doses; 1, 5, and 15 mg/flap) improved survival area compared with the control group. Glibenclamide abolished their protective effect. KATP channels may have a key role in anti-ischemic properties of IPC and pharmacologic preconditioning.

Complications of Complex Lower Urinary Tract Reconstruction in Patients With Neurogenic Versus Nonneurogenic Bladder—Is There a Difference?

PURPOSE The complications of lower urinary tract reconstruction have been well documented in children with neurogenic bladders. While most series include small numbers of nonneurogenic diagnoses, this group is typically underrepresented. Despite a number of fundamental anatomical and functional differences, a direct comparison of surgical complications of lower urinary tract reconstruction in patients with neurogenic vs nonneurogenic bladders has not been performed. MATERIALS AND METHODS We identified patients undergoing lower urinary tract reconstruction incorporating enterocystoplasty from 1996 to 2006. We performed a retrospective review of operative notes and medical records of patients who met inclusion criteria. Patients were divided into a neurogenic group and a nonneurogenic group based on the underlying diagnosis. The 2 groups were compared with respect to demographics, historical data, operative techniques, perioperative morbidity, long-term complications and need for surgical revision. RESULTS Of the 127 patients who met inclusion criteria 72 were assigned to the nonneurogenic group and 55 to the neurogenic group. Overall the rates of significant perioperative morbidity (39%), long-term complications (54%) and need for surgical revision (39%) were substantial. The rates of catheter related complications, rehospitalization for dehydration and spontaneous bladder rupture were higher in the neurogenic group (p <0.05). CONCLUSIONS Reconstruction of the lower urinary tract in children is associated with a considerable rate of complications and need for surgical revision regardless of whether the bladder is neurogenic or nonneurogenic. Children with neurogenic bladders are more prone to spontaneous rupture, catheter mishaps and early rehospitalization for dehydration.