Dongdeuk Kwon

Bone-Marrow-Derived Mesenchymal Stem Cell Transplantation Enhances Closing Pressure and Leak Point Pressure in a Female Urinary Incontinence Rat Model

Purpose: The purpose of this study was to determine whether periurethral injection of allogenic mesenchymal stem cells (MSCs) could increase the leak point pressure (LPP) in a rat model of stress urinary incontinence. Materials and Methods: Female Sprague-Dawley rats (230–240 g, n = 30) were divided into 3 groups: sham operation (group C), saline-treated (group S) and MSC-treated (group M). Bilateral pudendal nerve dissection followed by normal saline or MSC injection on both sides of the urethra was done. LPP and closing pressure (CP) testing was performed after the treatment. The specific markers for smooth muscle cells in the transplantation sites of the urethra were determined. Results: Both the LPP and CP were significantly lower in group S than controls. However, these were restored to the control values in group M (p < 0.05). The LPPs of groups C, S and M were 29.1 ± 2.1, 22.0 ± 2.2 and 43.1 ± 3.2 cm H2O, respectively. The CPs of groups C, S and M were 27.1 ± 3.1, 21.1 ± 3.2, and 32.1 ± 2.1 cm H2O, respectively. The injected MSCs stained positive for muscle-specific markers. Conclusion: This study suggests that MSCs might differentiate into muscle lineage cells and may contribute to the repair of damaged muscle tissue.

HOXB13 promotes androgen independent growth of LNCaP prostate cancer cells by the activation of E2F signaling.

BackgroundAndrogen signaling plays a critical role in the development of prostate cancer and its progression. However, androgen-independent prostate cancer cells emerge after hormone ablation therapy, resulting in significant clinical problems. We have previously demonstrated that the HOXB13 homeodomain protein functions as a prostate cancer cell growth suppressor by inhibiting androgen-mediated signals. However, the role of the HOXB13 in androgen-independent growth of prostate cancer cells remains unexplained.ResultsIn this report, we first demonstrated that HOXB13 was highly overexpressed in hormone-refractory tumors compared to tumors without prostate-specific antigen after initial treatment. Functionally, in an androgen-free environment minimal induction of HOXB13 in LNCaP prostate cancer cells, to the level of the normal prostate, markedly promoted cell proliferation while suppression inhibited cell proliferation. The HOXB13-mediated cell growth promotion in the absence of androgen, appears to be mainly accomplished through the activation of RB-E2F signaling by inhibiting the expression of the p21waf tumor suppressor. Indeed, forced expression of HOXB13 dramatically decreased expression of p21waf; this inhibition largely affected HOXB13-mediated promotion of E2F signaling.ConclusionsTaken together, the results of this study demonstrated the presence of a novel pathway that helps understand androgen-independent survival of prostate cancer cells. These findings suggest that upregulation of HOXB13 is associated with an additive growth advantage of prostate cancer cells in the absence of or low androgen concentrations, by the regulation of p21-mediated E2F signaling.

Distribution of interstitial cells of cajal and expression of nitric oxide synthase after experimental bladder outlet obstruction in a rat model of bladder overactivity

Recent studies have showed that interstitial cells (ICs) are widely distributed in the genitourinary tract and have suggested their involvement in spontaneous electrical activity and muscle contraction. Nitric oxide (NO) is thought to play a role in bladder overactivity related with bladder outlet obstruction (BOO). The purposes of this study were to investigate the effect of bladder overactivity induced by BOO on ICs and nitric oxide synthase (NOS) isoforms in rat urinary bladder.

δ-Catenin promotes E-cadherin processing and activates β-catenin-mediated signaling: implications on human prostate cancer progression.

δ-Catenin binds the juxtamembrane domain of E-cadherin and is known to be overexpressed in some human tumors. However, the functions of δ-catenin in epithelial cells and carcinomas remain elusive. We found that prostate cancer cells overexpressing δ-catenin show an increase in multi-layer growth in culture. In these cells, δ-catenin colocalizes with E-cadherin at the plasma membrane, and the E-cadherin processing is noticeably elevated. E-Cadherin processing induced by δ-catenin is serum-dependent and requires MMP- and PS-1/γ-secretase-mediated activities. A deletion mutant of δ-catenin that deprives the ability of δ-catenin to bind E-cadherin or to recruit PS-1 to E-cadherin totally abolishes the δ-catenin-induced E-cadherin processing and the multi-layer growth of the cells. In addition, prostate cancer cells overexpressing δ-catenin display an elevated total β-catenin level and increase its nuclear distribution, resulting in the activation of β-catenin/LEF-1-mediated transcription and their downstream target genes as well as androgen receptor-mediated transcription. Indeed, human prostate tumor xenograft in nude mice, which is derived from cells overexpressing δ-catenin, shows increased β-catenin nuclear localization and more rapid growth rates. Moreover, the metastatic xenograft tumor weights positively correlate with the level of 29kD E-cadherin fragment, and primary human prostate tumor tissues also show elevated levels of δ-catenin expression and the E-cadherin processing. Taken together, these results suggest that δ-catenin plays an important role in prostate cancer progression through inducing E-cadherin processing and thereby activating β-catenin-mediated oncogenic signals.

Testicular catch up growth: the impact of orchiopexy age.

OBJECTIVE To compare the long-term follow-up growth of congenital, unilaterally palpable, undescended testes after orchiopexy according to age at the time of surgery. The optimal age for surgical treatment remains controversial. MATERIALS AND METHODS A total of 86 patients (108 testes) between the ages of 1 and 9 years underwent orchiopexy. Patients were divided according to age at the time of surgery: group I, <2 years (n = 43); group II, 2 ≤ age < 5 years (n = 35); and group III, ≥5 years (n = 30). The boys were then followed for more than 2 years after surgery. Ultrasonography was used for determination of testicular volume. Testicular volume percentage was compared by the equation of (operated testis volume/normal testis volume × 100%). RESULTS Testicular location was the inguinal canal in 92 (85.2%) and lower to the external inguinal ring in 16 (14.8%). Only group I, which received orchiopexy within two years from birth, showed significant recovery of testicular volume at follow-up (P <.05), compared with groups II and III. CONCLUSIONS Orchiopexy performed at less than 2 years from birth was a significant factor for recovery of delayed cryptorchid testicular growth. This result suggests that early orchiopexy improves subsequent testicular catch-up growth.

Impact of Nocturia on Health-Related Quality of Life and Medical Outcomes Study Sleep Score in Men

Purpose To evaluate the impact of nocturia on health-related quality of life and sleep in men. Methods From January 2008 to December 2008, 284 patients with lower urinary tract symptoms were selected for this study. The participants completed a series of questionnaires on health-related quality of life (the overactive bladder questionnaire, or OAB-q), the Medical Outcomes Study (MOS) sleep scale, and the frequency volume chart. Results The patient population had a mean age of 60.0±13.4 years (range, 40 to 79 years). The mean duration of symptoms was 28.8±34.6 months. The mean number of voiding episodes per night was measured as follows: 88 patients (31.0%) reported no nocturia, 60 patients (21.1%) reported 2>voids/night ≥1, 56 patients (19.7%) reported 3>voids/night ≥2, and 80 patients (28.2%) reported ≥3 voids/night. The mean number of nocturia episodes increased with age (P=0.001), and the number of nocturia episodes was significantly associated with the OAB-q symptom score (P=0.001) and symptom bother (P=0.001). Among the categories of the MOS sleep scale, sleep index I (P=0.020), sleep disturbance (P=0.010), adequacy of sleep (P=0.005), and somnolence (P=0.041) were significantly associated with an increased number of nocturia episodes. Conclusions The number of nocturia episodes increased with age in men. Nocturia appeared to be associated with further negative effects on sleep quality, health-related quality of life, and symptom bother.

Effect of detrusor overactivity on the expression of aquaporins and nitric oxide synthase in rat urinary bladder following bladder outlet obstruction

BACKGROUND Aquaporins (AQPs) have recently been reported to be expressed in rat and human urothelium. Nitric oxide (NO) is thought to play a role in the bladder overactivity related to bladder outlet obstruction (BOO). The purpose of this study is to investigate the effect of BOO on the expression of AQP2-3 and nitric oxide synthase (NOS) isoforms in rat urothelium. METHODS Female Sprague-Dawley rats (230-240 g, n = 60) were divided into 2 groups. The control group (n = 30) and the partial bladder outlet obstruction (BOO) group (n = 30). After 4 weeks, we performed a urodynamic study to measure the contraction interval and contraction pressure. The expression and cellular localization of AQP2-3, endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) were determined by Western blot and immunohistochemistry. RESULTS On the cystometrogram, the estimated contraction interval time (minutes, mean ± SE) was significantly lower in the BOO group (3.0 ± 0.9) than in the control group (6.3 ± 0.4; p < 0.05). AQP2 was localized in the cytoplasm of the epithelium, whereas AQP3 was found only in the cell membrane of the epithelium. The protein expression of AQP2-3, eNOS and nNOS was significantly increased in the BOO group. CONCLUSION Detrusor overactivity induced by BOO causes a significant increase in the expression of AQP2-3, eNOS, and nNOS in rat urinary bladder. This may imply that the AQPs and NOS isoforms have a functional role in the bladder dysfunction that occurs in association with BOO.

Expression and Localization of Aquaporins in Benign Prostate Hyperplasia and Prostate Cancer

The aquaporin (AQP) families of water channels are intrinsic membrane proteins that facilitate selective water and small solute movement across the plasma membrane. The purposes of this study were to determine the expression and localization of AQPs in benign prostatic hyperplasia and prostate cancer. Prostatic tissue was collected from patients with benign prostatic hyperplasia or prostate cancer by transurethral resection of the prostate. The expression and cellular localization of the AQPs were determined in the human prostate by Western blot and immunohistochemistry. AQP1, 3, and 9 were expressed in the human prostate. Western blot analysis revealed bands at 28-36 kDa for the AQP1, 3, and 9 proteins. Of these proteins, AQP3 and 9 were expressed in the epithelium. Immunolabeling showed that AQP1 was mainly expressed in the capillaries and venules of the prostate, AQP9 was expressed in the cytoplasm of the epithelium, and AQP3 was mainly associated with the plasma membrane of the prostatic epithelium. Only AQP3 expression was localized in the cell membrane, and expressed AQP3 was translocated to the cytoplasm in prostate cancer. The epithelium in the human prostate expresses AQP3 and 9 proteins, and the capillaries and venules of the prostate express AQP1. Characterizing or modifying the expression of AQP3 may lead to an understanding of the role of the AQPs in human prostatic disease.

Prostate calculi in cancer and BPH in a cohort of Korean men: presence of calculi did not correlate with cancer risk.

Prostatic calculi are common and are associated with inflammation of the prostate. Recently, it has been suggested that this inflammation may be associated with prostate carcinogenesis. The aim of this study was to investigate the relationship between prostatic calculi and prostate cancer (PCa) in prostate biopsy specimens. We retrospectively analyzed 417 consecutive patients who underwent transrectal ultrasonography (TRUS) and prostate biopsies between January 2005 and January 2008. Based on the biopsy findings, patients were divided into benign prostatic hyperplasia and PCa groups. TRUS was used to detect prostatic calculi and to measure prostate volume. The correlations between PCa risk and age, serum total PSA levels, prostate volume, and prostatic calculi were analyzed. Patient age and PSA, as well as the frequency of prostatic calculi in the biopsy specimens, differed significantly between both the groups (P < 0.05). In the PCa group, the Gleason scores (GSs) were higher in patients with prostatic calculi than in patients without prostatic calculi (P = 0.023). Using multivariate logistic regression analysis, we found that patient age, serum total PSA and prostate volume were risk factors for PCa (P = 0.001), but that the presence of prostatic calculi was not associated with an increased risk of PCa (P = 0.13). In conclusion, although the presence of prostatic calculi was not shown to be a risk factor for PCa, prostatic calculi were more common in patients with PCa and were associated with a higher GS among these men.

Efficacy of Virtual Glasses in Audio–Visual Sexual Stimulation During Penile Color Duplex Doppler Ultrasonography

OBJECTIVE To examine whether audio-visual sexual stimulation (AVSS) with virtual glasses is effective in improving the recording of penile hemodynamics during penile color duplex Doppler ultrasonography. PATIENTS AND METHODS A total of 64 consecutive patients with erectile dysfunction underwent penile color duplex Doppler ultrasonography after intracavernosal injection of 10-20 microg prostaglandin El and subsequent genital stimulation. AVSS with virtual glasses and earphones was applied when peak systolic velocities (PSV) were less than 35 cm/s or end diastolic velocities (EDV) were more than 5 cm/s. PSV, EDV and the resistive index of both cavernosal arteries were continuously monitored. Clinical erectile response was assessed with visual inspection and manual palpation. RESULTS AVSS with virtual glasses was performed on 40 of 64 patients. AVSS improved the clinical erectile response in 26 (65%) of 40 patients. Doppler ultrasonography without AVSS identified 11 (27.5%), 5 (12.5%), and 24 (60%) patients with arteriogenic, veno-occlusive, and mixed-type impotence, respectively. However, after real-time AVSS 15 (37.5%), 7 (17.5%), 8 (20%), and 10 (25%) patients demonstrated non-vasculogenic, arteriogenic, veno-occlusive, and mixed-type impotence, respectively. Real-time AVSS improved the Doppler wave forms in 65% of cases. CONCLUSION AVSS with virtual glasses improves the recording of physiologic erectile response and may be used as a valuable tool during penile color duplex Doppler ultrasonography.