Photoselective Vaporesection of the Prostate with a Front-firing Lithium Triborate Laser: Surgical Technique and Experience After 215 Procedures.

BACKGROUD: Although photoselective vaporization of the prostate (PVP) is considered one of the most promising alternatives to transurethral radical prostatectomy, a longer operative time, an unsatisfactory tissue removal rate, and the absence of postoperative pathology samples remain the main criticisms for this procedure. OBJECTIVE: To describe the novel technique of photoselective vaporesection of the prostate (PVRP) with a front-firing lithium triborate (LBO) laser and to report our initial experience. DESIGN, SETTING, AND PARTICIPANTS: This is a prospective study of 215 patients undergoing PVRP between November 2011 and March 2013. Their average age, prostate size, and International Prostate Symptom Score (IPSS) were 70.3 ± 7.3 yr, 70.4 ± 34.0 ml, and 24.9 ± 5.0, respectively. SURGICAL PROCEDURE: The operative technique is detailed in the accompanying video. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Perioperative data were collected. The patients were followed up at 3, 6, 12 mo after PVRP, and functional outcomes and complications were assessed. RESULTS AND LIMITATIONS: The mean operation time was 44.1 ± 22.6 min. The mean hemoglobin decrease was 0.37 ± 0.21 g/dl. The catheterization time was 23.9 ± 15.2 h and the postoperative hospital stay was 1.8 ± 0.8 d. Significant improvements were observed in maximum flow, IPSS, and postvoid residual urine at each follow-up time point. Compared to preoperative values, prostate volume and serum prostate-specific antigen fell by 67% and 63%, respectively, at 3 mo after PVRP. No major complications were noted. Application of a hemostat for a front-firing LBO laser makes it easy to handle intractable intraoperative bleeding. The main limitation of this study is the short follow-up period. The influence of PVRP on sexual function and the learning curve remain to be evaluated. CONCLUSIONS: PVRP is a novel technique that is effective and safe for treatment of benign prostatic hyperplasia. This technique retains the excellent hemostatic property of LBO lasers and has a short operation time and a high tissue removal rate. The problem of the lack of postoperative tissue samples for PVP is also overcome in PVRP. PATIENT SUMMARY: We have developed a novel technique named photoselective vaporesection of the prostate (PVRP) with a front-firing green laser. Our results show that PVRP retains the excellent hemostatic property of a green laser, but has a much shorter operation time and a higher rate of tissue removal than photoselective vaporization of the prostate (PVP). This technique also solves the problem of the lack of postoperative tissue specimens and the difficulty of handling intractable intraoperative bleeding. According to our initial results, PVRP is a novel technique superior to PVP in the treatment of benign prostatic hyperplasia.

Testosterone regulates keratin 33B expression in rat penis growth through androgen receptor signaling.

Androgen therapy is the mainstay of treatment for the hypogonadotropic hypogonadal micropenis because it obviously enhances penis growth in prepubescent microphallic patients. However, the molecular mechanisms of androgen treatment leading to penis growth are still largely unknown. To clarify this well-known phenomenon, we successfully generated a castrated male Sprague Dawley rat model at puberty followed by testosterone administration. Interestingly, compared with the control group, testosterone treatment stimulated a dose-dependent increase of penis weight, length, and width in castrated rats accompanied with a dramatic recovery of the pathological changes of the penis. Mechanistically, testosterone administration substantially increased the expression of androgen receptor (AR) protein. Increased AR protein in the penis could subsequently initiate transcription of its target genes, including keratin 33B (Krt33b). Importantly, we demonstrated that KRT33B is generally expressed in the rat penis and that most KRT33B expression is cytoplasmic. Furthermore, AR could directly modulate its expression by binding to a putative androgen response element sequence of the Krt33b promoter. Overall, this study reveals a novel mechanism facilitating penis growth after testosterone treatment in precastrated prepubescent animals, in which androgen enhances the expression of AR protein as well as its target genes, such as Krt33b.

Downregulation of mTOR by lentivirus inhibits prostate cancer cell growth.

Prostate cancer, one of the most lethal forms of urinary system cancer, remains resistant to currently available treatments. Therefore, novel mechanism and target-based approaches are needed for the management of this neoplasm. PI3K/AKT signaling pathway activation correlates with human prostate cancer progression and metastasis. However, the role of mTOR in prostate cancer is not well-established. Here, we demonstrate that mTOR is over-expressed in both clinical tissue specimens and cultured human prostate cancer cells when compared to normal prostate tissues, respectively. Further, mTOR gene knockdown via lentivirus mediated mTOR specific shRNA resulted in a significant decrease in the viability and growth of prostate cancer cells without affecting normal human prostate cells. In addition, mTOR inhibition resulted in a significant i) decrease in 4EBP1, S6K, PI3K and AKT protein, ii) increase in PARP protein of prostate cancer cells. Most importantly, mTOR inhibition triggered apoptosis and suppressed pancreatic carcinoma growth in vivo in a mouse xenograft model. We suggest that targeting of mTOR may be a viable approach for the treatment of prostate cancer.

Relationships among androgen receptor CAG repeat polymorphism, sex hormones and penile length in Han adult men from China: a cross-sectional study.

This study aimed to investigate the correlations among androgen receptor (AR) CAG repeat polymorphism, sex hormones and penile length in healthy Chinese young adult men. Two hundred and fifty-three healthy men (aged 22.8 ± 3.1 years) were enrolled. The individuals were grouped as CAG short (CAG S ) if they harbored repeat length of ≤ 20 or as CAG long (CAG L ) if their CAG repeat length was >20. Body height/weight, penile length and other parameters were examined and recorded by the specified physicians; CAG repeat polymorphism was determined by the polymerase chain reaction (PCR) method; and the serum levels of the sex hormones were detected by radioimmunoassay. Student's t-test or linear regression analysis was used to assess the associations among AR CAG repeat polymorphism, sex hormones and penile length. This investigation showed that the serum total testosterone (T) level was positively associated with the AR CAG repeat length (P = 0.01); whereas, no significant correlation of T or AR CAG repeat polymorphism with the penile length was found (P = 0.593). Interestingly, an inverse association was observed between serum prolactin (PRL) levels and penile length by linear regression analyses (ß= -0.024, P = 0.039, 95% confidence interval (CI): -0.047, 0). Collectively, this study provides the first evidence that serum PRL, but not T or AR CAG repeat polymorphism, is correlated with penile length in the Han adult population from northwestern China.

Prostate-targeted mTOR-shRNA inhibit prostate cancer cell growth in human tumor xenografts.

OBJECTIVE: To construct a recombinant lentivirus vector driven by the PSMA promoter carrying mTOR-shRNA, and to obtain the effect on the mTOR gene silencing in human prostate cancer xenografts. METHODS: The complimentary oligos of small interference RNA (siRNA) with hairpin structures targeting the mTOR gene and a negative control were synthesized, then ligated with pLV-PSMA-promoter vector and sequenced. The recombinant vectors were then transfected with viral packaging mix into 293T cells, viral supernatant was harvested to determine the titer. Prostate cancer cells infected by virus were harvested and the expression of mTOR (LV-PSMA-shmTOR), target proteins and cell growth were detected by reverse transcription-PCR (RT-PCR), Western blot and MTT separately. In established tumors derived from human prostate cancer cells, concentrated LV-PSMA-shmTOR lentivirus was injected intravenously in the tail vein of C4-2b tumor bearing female severe combined immunodeficient (SCID) mice. Tumor volume and immunohistochemistry was assessed. RESULTS: Sequencing data showed that the constructed plasmids contained the correct sequences of mTOR siRNA transcript templates. A vector producing cell line 293T was established, and the titer for transfection was obtained. RT-PCR, Western blot and MTT analyses demonstrated that mTOR shRNA expression construct could suppress the expression of mTOR and inhibit the prostate cancer cell growth, specially. The tumor growth was suppressed in nude mouse. CONCLUSION: A PSMA driven lentivirus mediated siRNA targeting mTOR gene was successfully constructed, which decreased the expression of mTOR and induced the prostate cancer cell growth in vitro and in vivo. It has set up a research platform for the gene therapy of tumors which take mTOR as the target in the prostate cancer field.

Holmium laser enucleation of the prostate: a modified enucleation technique and initial results.

PURPOSE: Although holmium laser enucleation of the prostate has been proven to be an excellent technique for the treatment of benign prostatic hyperplasia, it has not been widely applied due to technical difficulties and longer operative time. We modified the current technique of enucleation and present our initial experience. MATERIALS AND METHODS: A total of 189 patients with benign prostatic hyperplasia underwent prostatectomy with our modified technique for holmium laser enucleation of the prostate. Intraoperative and postoperative data were prospectively collected. For followup International Prostate Symptom Score, quality of life, maximal flow rate and post-void residual urine were recorded. RESULTS: Mean±SD preoperative prostate volume was 78.1±24.3 cc and 60.9±39.2 gm tissue were enucleated. Mean operative and enucleation times were 54.7±21.1 and 36.5±16.3 minutes, respectively. Mean serum hemoglobin decrease was 0.98±0.72 gm/dl. Mean catheter time was 1.2±0.5 days and mean postoperative hospital stay was 4.9±3.4 days. Serious complications were not observed. Three patients complained of transient stress incontinence which resolved within 3 months. Significant improvement occurred in International Prostate Symptom Score, quality of life, maximal flow rate and post-void residual urine volume at 3 and 6-month followup compared with the preoperative baseline. CONCLUSIONS: The modified holmium laser enucleation of the prostate technique is effective and safe when treating benign prostatic hyperplasia.

Deprival of testicular innervation induces apoptosis of Leydig cells via caspase-8-dependent signaling: a novel survival pathway revealed.

Leydig cells are the primary source of testosterone in adult males. Recently, a growing body of evidence has shown that testicular innervation functions as a major regulator in Leydig cell steroidogenesis. The question then arises whether this novel regulatory pathway also plays an important role in other biological behaviors of this cell type. In the present study, we selectively resected the superior spermatic nerves (SSNs) or the inferior spermatic nerves (ISNs) to investigate the effects of testicular denervation on survival of Leydig cells. After testicular denervation, Leydig cells displayed morphological characteristics of apoptosis, such as chromatin condensation, cell shrinkage and apoptotic body formation. Flow cytometry combined with TUNEL labeling demonstrated dramatic and persistent apoptosis of Leydig cells in the denervated testes 14 and 21 days after operation. Meanwhile, serum T concentrations in the SSN- or ISN-denervated rats dramatically decreased on day 14 and declined further on day 21. Plasma LH levels underwent a remarkable rise, while serum FSH levels remained unchanged. Immunofluorescent staining and flow cytometry further demonstrated that testicular denervation activated caspase-3 and caspase-8, but not caspase-9 in Leydig cells. Our data indicate that testicular innervation functions as an important survival factor for Leydig cells in vivo.

Peptidergic not monoaminergic fibers profusely innervate the young adult human testis.

Numerous studies have reported that intratesticular nerves exert important regulatory effects on the functions of the male gonad; however, as yet little is known about their distribution in the young adult human testis. The purpose of this study was to explore whether peptidergic and adrenergic nerves occur in the male gonad of this age, and, if present, to depict their distribution further. Thirty testes were collected from 15 reproductively healthy donors aged 21-32 years. Antibodies against protein gene product 9.5 (PGP 9.5), neuropeptide Y (NPY), C-terminal flanking peptide of NPY (CPON) and vasoactive intestinal peptide (VIP) were employed for immunohistochemical detection of intratesticular peptidergic nerves, and those against dopamine-beta-hydroxylase (DBH) and 5-hydroxytryptamine (5-HT) for monoaminergic ones. The testicular parenchyma exhibited a rich innervation by PGP 9.5-positive fibers, mainly associated with Leydig cell nests, blood vessels, and seminiferous tubules. Numerous NPY- and CPON-immunoreactive (IR) nerves also appeared in the gonads, but the vast majority were confined to blood vessels. A small number of VIP-IR fibers were detected in some arterioles. By contrast, however, no fibers displaying DBH or 5-HT immunoreactivity were observed within the testis. Additionally, expression of PGP-9.5, NPY, CPON, VIP, DBH and 5-HT was found in Leydig cells, PGP 9.5 in spermatogonia, and NPY and CPON in peritubular myoid cells. Our results suggest that the young adult human testis is devoid of monoaminergic nerves but profusely innervated by peptidergic fibers, which may serve as major neuronal regulators for testicular functions at this age.

[Apoptosis in male germ cells induced by testicular denervation].

OBJECTIVE: To evaluate the role of spermatic nerves in the regulation of spermatogenesis. METHODS: Fifty-four mature SD male rats (350-375 g) were randomized into a sham operation group (SO) and three experiment groups, and the latter underwent bilateral surgical removal of the superior spermatic nerve (SSN) or/and the inferior spermatic nerve (ISN). The animals were killed 1 month and 2 months after the operation. HE stain was used to observe spermatogenesis. Transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) were employed to detect apoptosis. RESULTS: Impaired spermatogenesis was observed 2 months after the operation, with only Sertoli cells and a few spermatogonia remaining in the regressed tubules in all the treatment groups. The abnormal tubules in the SSN, ISN and SSN + ISN denervated testes accounted for (13.25 +/- 2.03)%, (11.0 +/- 4.36)% and (34.17 +/- 3.78)% respectively. Chromosome condensation and fragmentation in the germ cells were observed under the electron transmission microscope in all the denervated testes. TUNEL showed the spermatogonia and Leydig cells to be apoptotic in all the denervated testes and the incidence of the apoptotic cells in the SSN + ISN denervated testes was significantly higher than in the SSN or ISN denervated ones. CONCLUSION: Spermatic nerves play an important role in spermatogenesis.

[Expression of Bax and Bcl-2 gene in rat testis tissues induced by testicular denervation].

OBJECTIVE: To detect the changes of the expression of Bax and Bcl-2 gene in the denervated testis, and to explore the possible mechanisms underlying the apoptosis of germ cells induced by testicular denervation at the genetic translation level. METHODS: Eighteen mature SD rats (350-375 g) were equally divided into 3 groups: a sham operation group( SO) , a superior spermatic nerve group (SSN) and an inferior spermatic nerve group (ISN) , and the latter two received bilateral surgical removal of the superior spermatic nerve and the inferior spermatic nerve, respectively. The animals were killed I month after the operation. ISH SP-method was used to detect the expression of Bax and Bcl-2 protein. RESULTS: Significant up-regulation of Bax protein was detected in both the treatment groups 1 month after surgery( P <0. 05) , and the level of Bcl-2 protein remained unchanged. CONCLUSION: Bax gene is involved in the apoptosis of germ cells induced by testicular denervation.