Silodosin: a selective alpha1A-adrenergic receptor antagonist for the treatment of benign prostatic hyperplasia

State-of-the-art mathematically induced filtration approaches for smart spectrophotometric assessment of silodosin and solifenacin mixture in their new challenging formulation: Multi-tool greenness and whiteness evaluation

Benign prostatic hyperplasia is one of the most predominant health disorders in men with increasing incidence by age and usually accompanied with other bothersome symptoms. A new fixed dose combination, containing Silodosin and Solifenacin, has been recently launched for relieving such disorder associated with overactive bladder syndrome. In the current work, three smart, innovative and white spectrophotometric methods have been newly developed and optimized for simultaneous determination of the studied drugs in their binary mixture using water as an eco-friendly solvent. The adopted strategy relied on calculation of one or two factors as numerical constant or spectrum allowing mathematical filtration of desired analyte and full removal of any overlapped components in the mixture. The developed methods are categorized over two spectrophotometric platform windows. Window I deals with absorption spectra in its native forms (zero-order) including a newly developed method termed induced concentration subtraction (ICS) as well as induced dual wavelength (IDW) methods. Whereas window III is concerned with ratio spectra as in induced amplitude modulation (IAM) method. Compared to classical spectrophotometric methods, the proposed ones are superior in overcoming the inherited challenges in zero-order absorption spectrum of Solifenacin, particularly its very low absorptivity and lack of unique absorption maximum. Validity of the methods were thoroughly assured as per ICH guidelines with unified regression over 3.0-50.0 µg/mL in ICS method while IDW and IAM ones possessed linearity ranges of 3.0-50.0 µg/mL of Silodosin and 5.0-60.0 µg/mL of Solifenacin. The work was also extended to verify content uniformity of dosage units in accordance with USP recommendations. Greenness profile of the proposed methods was clearly assessed, in comparison to the reported analysis ones, via state-of-the-art software metrics, namely, green solvent selection tool (GSST), complementary green analytical procedure index (ComplexGAPI) and analytical greenness (AGREE). Finally, the proposed methods were in good adherence to the recently published postulates of white analytical chemistry.

Prophylactic A-Blockers for Radiotherapy-Induced Lower Urinary Tract Symptoms in Men with Prostate Cancer: A Phase III Randomized Trial

PURPOSE

The present phase III randomized trial assessed the efficacy of prophylactic versus therapeutic α-blockers at improving RI-LUTSs in prostate cancer patients receiving external beam radiotherapy (EBRT).

METHODS

A total of 148 prostate cancer patients were randomized 1:1 to receive either prophylactic silodosin on day one of EBRT or the occurrence of RI-LUTSs. LUTSs were quantified using the international prostate symptom score (IPSS) at regular intervals during the study. The primary endpoint was the change in the IPSS from baseline to the last day of radiotherapy (RT). Secondary endpoints included changes in IPSS from baseline to 4 weeks and 12 weeks after the start of RT.

RESULTS

Patient demographics, baseline IPSS, and prescribed radiation doses were balanced between arms. On the last day of RT, the mean IPSS was 14.8 (SD 7.6) in the experimental arm and 15.7 (SD 8.5) in the control arm (p = 0.40). There were no significant differences in IPSSs between the study arms in the intention-to-treat (ITT) analysis at baseline, the last day of RT, and 4 and 12 weeks post-RT.

CONCLUSION

Prophylactic α-blockers were not effective at significantly reducing RI-LUTSs in prostate cancer patients treated with EBRT. Treating patients with α-blockers at the onset of RI-LUTSs will avoid unnecessary drug exposure and toxicity.

Comparison of primary care prescriptions for old and very old hypertensive patients

BACKGROUND

Elderly and very elderly individuals might be subject to different approaches for the treatment of hypertension. We aimed to compare drug utilization in hypertensive old patients and very old patients in primary care, along with the evaluation of potentially inappropriate drug prescribing.

METHODS

In this cross-sectional study, we compared prescriptions of 65-79-year-old (old patient prescriptions [OPP], n = 433,988) vs. ≥80-year-old (very old patient prescriptions [VOPP], n = 134,079) with "essential hypertension" diagnosis, issued by 3:1 systematically-sampled primary care physicians (n = 1431) in İstanbul throughout 2016. Drug utilization patterns and distribution of antihypertensives based on drug class and combination status were evaluated. Frequency of potentially inappropriate drugs per Beers Criteria were identified and compared.

RESULTS

Antihypertensive monotherapy practice was less common in OPP than VOPP (43.3% vs. 45.3%; p < 0.001). In both groups,the most commonly prescribed drugs were beta-blockers for monotherapy (37.4% vs. 33.1%, p < 0.001) and thiazide diuretics for combined therapy (69.8% vs. 67.4%, p < 0.001). Metoprolol was the most commonly prescribed antihypertensive both in OPP and VOPP (15.3% vs. 14.8%). Furosemide was ranked 10th in OPP and 3rd in VOPP (2.7% vs. 5.5%). Cardiovascular system drugs were the most commonly encountered potentially inappropriate medications in both groups (263.9 vs. 283.4 per 10,000 prescriptions, p = 0.004). Regarding antihypertensive drugs, 2.2% of those in OPP and 2.4% of those in VOPP were identified as potentially inappropriate (p = 0.002).

DISCUSSION

Prescribing preferences to old and very old patients mostly showed slight differences. Almost half of prescriptions comprising antihypertensive monotherapy might imply hesitancy to prescribe combinations. Overuse of risky drugs such as furosemide in both groups, especially in the very elderly, requires more attention.

α1-Adrenergic Receptors: Insights into Potential Therapeutic Opportunities for COVID-19, Heart Failure, and Alzheimer's Disease

α1-Adrenergic receptors (ARs) are members of the G-Protein Coupled Receptor superfamily and with other related receptors (β and α2), they are involved in regulating the sympathetic nervous system through binding and activation by norepinephrine and epinephrine. Traditionally, α1-AR antagonists were first used as anti-hypertensives, as α1-AR activation increases vasoconstriction, but they are not a first-line use at present. The current usage of α1-AR antagonists increases urinary flow in benign prostatic hyperplasia. α1-AR agonists are used in septic shock, but the increased blood pressure response limits use for other conditions. However, with the advent of genetic-based animal models of the subtypes, drug design of highly selective ligands, scientists have discovered potentially newer uses for both agonists and antagonists of the α1-AR. In this review, we highlight newer treatment potential for α1A-AR agonists (heart failure, ischemia, and Alzheimer's disease) and non-selective α1-AR antagonists (COVID-19/SARS, Parkinson's disease, and posttraumatic stress disorder). While the studies reviewed here are still preclinical in cell lines and rodent disease models or have undergone initial clinical trials, potential therapeutics discussed here should not be used for non-approved conditions.

Effect of α1D-adrenoceptor blocker for the reduction of ureteral contractions

PURPOSE

Urolithiasis is a common urinary tract disease with growing prevalence. Alpha1-adrenoceptors (α1-ARs) are abundant in ureteral smooth muscle, distributed with different α1-AR subtypes. α1D-AR is the most widely distributed in the ureter. However, the effect of α1D-AR blockade on ureteric contraction remains unknown.

MATERIALS AND METHODS

We dissected smooth muscle tissues (3 mm×3 mm) from the rat bladder and human ureter, tied silk strips on both tissue ends, and measured contraction in an organ bath chamber. Contraction activity in ureteral smooth muscle cells (USMCs) was immunocytochemically examined using primary rat and human USMC cultures.

RESULTS

Using the organ bath system, we determined the inhibitory effects of silodosin, tamsulosin, and naftopidil. Naftopidil significantly decreased contractility of rat bladder tissue; similar results were observed in human ureteral tissue. To confirm ex vivo experimental results in vitro , we examined the phosphorylation of myosin light chain (MLC), a marker of contractility, in a primary human USMC culture. The examined drugs decreased phospho-MLC levels in human USMCs; however, naftopidil profoundly increased MLC dephosphorylation.

CONCLUSIONS

We studied the effects of naftopidil, an α1D-AR inhibitor, on the ureter. Compared with alpha-blockers, naftopidil significantly relaxed ureteral smooth muscle. Therefore, naftopidil could be an effective therapy for patients with ureteral stones.

Fingerprinting and iso-absorptive resolution techniques for the spectrally overlapping Dutasteride and Silodosin mixture: Content uniformity testing along with greenness profile assessment

The realm of spectrophotometric analysis has witnessed a remarkable progress in inventing faster and simpler resolution techniques for spectrally overlapping drug mixtures. Eco-friendly and progressive spectrophotometric methods were firstly developed in this work, for the simultaneous determination of Dutasteride (DUT) and Silodosin (SLD) in their newly-marketed dosage form. The proposed methods focused on the unique spectral features of this mixture including spectral extension of SLD over DUT spectrum as well as existence of iso-absorptive points. By such way, the methods were classified into two categories; the first one was "fingerprint resolution techniques" including constant extraction coupled with spectrum subtraction and ratio subtraction coupled with constant multiplication methods. The former represented a new modification to the classical constant extraction method where one divisor and lower steps were manipulated instead. The second category was "iso-absorptive resolution techniques", such as absorptivity centering, absorbance subtraction and amplitude modulation methods. Different solvents were investigated where ethanol was found to be the optimum one regarding drugs solubility, signal sensitivity and environmental, health & safety (EHS) score. Validity of the suggested methods was assessed as per ICH-guidelines and found to be linear over concentration ranges of 5.0-90.0 µg/mL for DUT and 5.0-120.0 µg/mL for SLD. The methods were successfully applied for quantifying the cited drugs in their combined dosage form and evaluating their content uniformity. Moreover, the insignificant statistical difference between the proposed methods and official HPLC ones encourages the utilization of such spectrophotometric methods as greener and faster candidates, especially in modest quality control laboratories. Methods' greenness profile was finally guaranteed through several assessment tools, namely; national environmental methods index (NEMI), analytical eco-scale, green analytical procedure index (GAPI) and analytical greenness (AGREE) metric.

Comparative efficacy and safety profile of 4 vs 8 mg of silodosin once daily usage in patients with benign prostatic hyperplasia-related lower urinary tract symptoms divided into subgroups according to International Prostate Symptom Score severity

Background

The purpose of this study was to compare once daily (QD) usage of 4 and 8 mg of silodosin in patients divided as those with moderate and with severe lower urinary tract symptoms (LUTSs) according to International Prostate Symptom Score (IPSS) categories in terms of effectiveness and adverse events.

Methods

A total of 234 patients aged ≥ 40 years were evaluated prospectively. All participants were divided firstly into two groups according to their IPSS severity as moderate and severe. They were further allocated to receive 4 mg of silodosin and 8 mg of silodosin QD. Demographic features and laboratory tests were recorded. The patients were questioned with International Index of Erectile Function-5 and IPSS along with quality of life index. Uroflowmetric measurements were applied to the patients. All tests and measurements were repeated at the 3rd month, and changes from pretreatment to posttreatment were analyzed by SPSS 21.0 Program. The statistical significance level was set at p < 0.05.

Results

Both treatments provided benefit in patients with both moderate and severe LUTSs. While results did not differ among 4 mg and 8 mg of silodosin in patients with moderate LUTSs, 8 mg of silodosin was significantly better than 4mg in those with severe LUTSs in terms of improvement of the total IPSS, IPSS voiding subtotal score, and quality of life score (p = 0.015, 0.030, <0.001, respectively). Both treatments did not affect erectile functions. Adverse events were seen more frequently in patients receiving 8 mg of silodosin than those treated with 4 mg of silodosin (p = 0.024).

Conclusion

Our study revealed that 4 mg of silodosin QD was as effective as 8 mg of silodosin QD in patients with moderate LUTSs but not with severe LUTSs. It can be inferred from this study that prescription of 4 and 8 mg of silodosin may be chosen to treat the patients with moderate and severe LUTSs due to benign prostatic heperplasia, respectively.

Silodosin: An Update on Efficacy, Safety and Clinical Indications in Urology

INTRODUCTION

Silodosin determines smooth muscle relaxation in bladder and prostate tissues, increases bladder blood flow in conditions of chronic bladder ischemia and regulates the activity of transcriptional factors responsible for stromal growth and prostate hyperplasia. Phase III trials have already demonstrated the efficacy and safety of silodosin in the treatment of patients bothered by lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH).

OBJECTIVE

We aimed to describe the rationality for the use of silodosin and to summarize the current literature on the use of Silodosin for the treatment of LUTS.

METHODS

PubMed and Web of Science were queried with the terms: 'silodosin' in combination (AND) with the terms 'lower urinary tract symptoms', 'LUTS', 'pathophysiology', 'symptoms' OR 'therapy'. Studies published in the last 10 years (2007-2017) in adults and core clinical journals in English were included.

RESULTS

Silodosin 8 mg once-daily was superior to placebo in improving IPSS total score, voiding subscore, storage subscore and QoL score, and at least as effective as tamsulosin 0.4 mg once-daily in all the efficacy analyses. In addition, studies assessing the effect on urodynamic parameters showed that silodosin determined a higher improvement in the bladder outlet obstruction index compared to other alpha1 adrenergic receptor antagonists. Concerning the safety profile, long-term data (after 9 months of treatment) confirmed the limited effect of silodosin on the cardiovascular and gastrointestinal systems. Although ejaculatory disorders represented the main complaint of patients taking silodosin, the discontinuation rate due to this condition remained low even in a long-term follow-up study (7.5%). Encouraging findings showed that silodosin may be administered as a medical expulsive therapy for promoting spontaneous stone passage of distal ureteral stones < 10 mm, to relieve LUTS in patients who underwent prostate cancer brachytherapy and to increase the likelihood of successful trials without a catheter in patients experiencing acute urinary retention.

CONCLUSION

Silodosin is one of the drugs approved for the treatment of BPH, being highly effective in improving not only LUTS but also urodynamic parameter impairments secondary to BPH. Moreover, it has shown efficacy as medical expulsive therapy for distal ureteral stones in previous prospective randomized trials.

FUNDING

Sponsorship for this study and article processing charges were funded by Recordati.

Silodosin for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia

BACKGROUND

A variety of alpha-blockers are used for treating lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH). Silodosin is a novel, more selective alpha-blocker, which is specific to the lower urinary tract and may have fewer side effects than other alpha-blockers.

OBJECTIVES

To assess the effects of silodosin for the treatment of LUTS in men with BPH.

SEARCH METHODS

We performed a comprehensive search using multiple databases (Cochrane Library, MEDLINE, EMBASE, Scopus, Google Scholar, and Web of Science), trials registries, other sources of grey literature, and conference proceedings with no restrictions on the language of publication or publication status up until 13 June 2017.

SELECTION CRITERIA

We included all parallel, randomized controlled trials. We also included cross-over designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies and abstracted data from the included studies. We performed statistical analyses using a random-effects model and interpreted them according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of evidence according to the GRADE approach.

MAIN RESULTS

We included 19 unique studies with 4295 randomized participants across four comparisons for short-term follow-up. The mean age, prostate volume, and International Prostate Symptom Score were 66.5 years, 38.2 mL, and 19.1, respectively. Silodosin versus placeboBased on four studies with a total of 1968 randomized participants, silodosin may reduce urologic symptom scores in an appreciable number of men (mean difference (MD) -2.65, 95% confidence interval (CI) -3.23 to -2.08; low-quality evidence). Silodosin likely does not result in a clinically important reduction in quality of life (MD -0.42, 95% CI -0.71 to -0.13; moderate-quality evidence). It may not increase rates of treatment withdrawal for any reason (relative risk (RR) 1.08, 95% CI 0.70 to 1.66; low-quality evidence). We are uncertain about the effect of silodosin on cardiovascular adverse events (RR 1.28, 95% CI 0.67 to 2.45; very low-quality evidence). Silodosin likely increases sexual adverse events (RR 26.07, 95% CI 12.36 to 54.97; moderate-quality evidence); this would result in 180 more sexual adverse events per 1000 men (95% CI 82 more to 388 more). Silodosin versus tamsulosinBased on 13 studies with a total of 2129 randomized participants, silodosin may result in little to no difference in urologic symptom scores (MD -0.04, 95% CI -1.31 to 1.24; low-quality evidence) and quality of life (MD -0.15, 95% CI -0.53 to 0.22; low-quality evidence). We are uncertain about treatment withdrawals for any reason (RR 1.02, 95% CI 0.62 to 1.69; very low-quality evidence). Silodosin may result in little to no difference in cardiovascular adverse events (RR 0.77, 95% CI 0.53 to 1.12; low-quality evidence). Silodosin likely increases sexual adverse events (RR 6.05, 95% CI 3.55 to 10.31; moderate-quality evidence); this would result in 141 more sexual adverse events per 1000 men (95% CI 71 more to 261 more). Silodosin versus naftopidilBased on five studies with a total of 763 randomized participants, silodosin may result in little to no differences in urologic symptom scores (MD -0.85, 95% CI -2.57 to 0.87; low-quality evidence), quality of life (MD -0.17, 95% CI -0.60 to 0.27; low-quality evidence), treatment withdrawal for any reason (RR 1.25, 95% CI 0.81 to 1.93; low-quality evidence), and cardiovascular adverse events (RR 1.02, 95% CI 0.41 to 2.56; low-quality evidence). Silodosin likely increases sexual adverse events (RR 5.93, 95% CI 2.16 to 16.29; moderate-quality evidence); this would result in 74 more sexual adverse events per 1000 men (95% CI 17 more to 231 more). Silodosin versus alfuzosinBased on two studies with a total of 155 randomized participants, silodosin may or may not result in a clinically important increase in urologic symptom scores (MD 3.83, 95% CI 0.12 to 7.54; low-quality evidence). Silodosin likely results in little to no difference in quality of life (MD 0.14, 95% CI -0.46 to 0.74; moderate-quality evidence). We found no event of treatment withdrawal for any reason. Silodosin may not reduce cardiovascular adverse events (RR 0.67, 95% CI 0.36 to 1.24; low-quality evidence) but likely increases sexual adverse events (RR 37.21, 95% CI 5.32 to 260.07; moderate-quality evidence); this would result in 217 more sexual adverse events per 1000 men (95% CI 26 more to 1000 more).

AUTHORS' CONCLUSIONS

Silodosin may reduce urologic symptom scores in an appreciable number of men compared to placebo. Quality of life and treatment withdrawals for any reason appears similar. Its efficacy appears similar to that of other alpha blockers (tamsulosin, naftopidil and alfuzosin) but the rate of sexual side effects is likely higher. Our certainty in the estimates of effect was lowered due to study limitations, inconsistency and imprecision.

A Prospective Study to Evaluate Sexual Dysfunction and Enlargement of Seminal Vesicles in Sexually Active Men Treated for Benign Prostatic Hyperplasia by Alpha-blockers

OBJECTIVE

To evaluate sexual dysfunction and enlargement of seminal vesicles in sexually active men who were treated by α1-blockers for benign prostatic hyperplasia and its possible clinical application.

MATERIALS AND METHODS

This is a prospective cohort study from January 2015 to December 2016. We enrolled sexually active men above the age of 40 years having moderate to severe lower urinary tract symptoms (LUTS). We excluded patients with a history of prostate surgery, suspicious digital rectal examination findings, a serum prostate-specific antigen of >4 ng/dL, and a history of medication with anticholinergic, cholinergic, and diuretic agents. Patients were divided into groups A, B, and C based on the prescription of silodosin 8 mg, tamsulosin 0.4 mg, or alfuzosin 10 mg orally once for LUTS and at 4 and 12 weeks.

RESULTS

The mean age was 54.8 years (41-68 years). Twelve weeks of treatment with silodosin, tamsulosin, and alfuzosin resulted in a significant improvement in the total International Prostate Symptom Score and the quality of life score (P <.001). The baseline erectile function scores were 26.4, 27.6, and 28.1, and the baseline overall satisfaction (OS) (International Index of Erectile Function [IIEF]-OS) scores were 7.1, 8.3, and 8.6 among groups A, B, and C, respectively. After 12 weeks of α1-blockers, the IIEF-erectile function scores were 24.0, 24.7, and 26.2, and the IIEF-OS scores were 6.4, 7.8, and 7.9. All 3 groups demonstrated a statistically significant enlargement of seminal vesicles after 12 weeks' treatment, most significant in group A patients (7.65-14.11 cc, P <.001).

CONCLUSION

Alpha-blockers as silodosin, tamsulosin, and alfuzosin are a safe and effective tool in benign prostatic hyperplasia for improving LUTS and the quality of life. Loss of seminal emission with alpha-blockers appears as the cause of seminal vesicle enlargement. The exact mechanism of these findings needs further clinical and experimental research.

Effect of Silodosin, an Alpha1A-Adrenoceptor Antagonist, on Ventral Prostatic Hyperplasia in the Spontaneously Hypertensive Rat

Background

A decreased prostatic blood flow could be one of the risk factors for benign prostatic hyperplasia/benign prostatic enlargement. The spontaneously hypertensive rat (SHR) shows a chronic prostatic ischemia and hyperplastic morphological abnormalities in the ventral prostate. The effect of silodosin, a selective alpha_1A-adrenoceptor antagonist, was investigated in the SHR prostate as a prostatic hyperplasia model focusing on prostatic blood flow.

Methods

Twelve-week-old male SHRs were administered perorally with silodosin (100 μg/kg/day) or vehicle once daily for 6 weeks. Wistar Kyoto (WKY) rats were used as normotensive controls and were treated with the vehicle. The effect of silodosin on blood pressure and prostatic blood flow were estimated and then the prostates were removed and weighed. The tissue levels of malondialdehyde (MDA), interleukin-6 (IL-6), chemokine (C-X-C motif) ligand 1/cytokine-induced neutrophil chemoattractant 1 (CXCL1/CINC1), tumor necrosis factor-alpha (TNF-α), transforming growth factor beta 1 (TGF-β1), basic fibroblast growth factor (bFGF) and alpha-smooth muscle actin (α-SMA) were measured. The histological evaluation was also performed by hematoxylin and eosin staining.

Results

There was a significant increase in blood pressure, prostate weight, prostate body weight ratio (PBR), tissue levels of MDA, IL-6, CXCL1/CINC1, TNF-α, TGF-β1, bFGF and α-SMA in the SHR compared to the WKY rat. The ventral prostate in the SHR showed the morphological abnormalities compared to the WKY rat. Prostatic blood flow was decreased in the SHR. However, treatment with silodosin significantly restored the decreased prostatic blood flow in the SHR. Moreover, silodosin normalized tissue levels of MDA, IL-6, CXCL1/CINC1, TNF-α, TGF-β1, bFGF and α-SMA, and it ameliorated ventral prostatic hyperplasia in the SHR excluding blood pressure. Silodosin decreased PBR but not prostate weight in the SHR.

Conclusions

Silodosin can inhibit the progression of prostatic hyperplasia through a recovery of prostatic blood flow.

Discovery of Novel Indazole Derivatives as Highly Potent and Selective Human β3-Adrenergic Receptor Agonists with the Possibility of Having No Cardiovascular Side Effects

Novel indazole derivatives were prepared and evaluated for their biological activity and cardiovascular safety profile as human β3-adrenergic receptor (AR) agonists. Although the initial hit compound 5 exhibited significant β3-AR agonistic activity (EC50 = 21 nM), it also exhibited agonistic activity at the α1A-AR (EC50 = 219 nM, selectivity: α1A/β3 = 10-fold). The major metabolite of 5, which was an oxidative product at the indazole 3-methyl moiety, gave a clue to a strategy for improvement of the selectivity for β3-AR agonistic activity versus α1A-AR agonistic activity. Thus, modification of the 3-substituent of the indazole moiety effectively improved the selectivity to develop compound 11 with potent β3-AR agonistic activity (EC50 = 13 nM) and high selectivity (α1A/β3 = >769-fold). Compound 11 was also inactive toward β1 and β2-ARs and showed dose dependent β3-AR mediated relaxation of marmoset urinary bladder smooth muscle, while it did not obviously affect heart rate or blood pressure (iv, 3 mg/kg) in anesthetized rats.

A New Combinatorial Optimization Approach for Integrated Feature Selection Using Different Datasets: A Prostate Cancer Transcriptomic Study

Background

The joint study of multiple datasets has become a common technique for increasing statistical power in detecting biomarkers obtained from smaller studies. The approach generally followed is based on the fact that as the total number of samples increases, we expect to have greater power to detect associations of interest. This methodology has been applied to genome-wide association and transcriptomic studies due to the availability of datasets in the public domain. While this approach is well established in biostatistics, the introduction of new combinatorial optimization models to address this issue has not been explored in depth. In this study, we introduce a new model for the integration of multiple datasets and we show its application in transcriptomics.

Methods

We propose a new combinatorial optimization problem that addresses the core issue of biomarker detection in integrated datasets. Optimal solutions for this model deliver a feature selection from a panel of prospective biomarkers. The model we propose is a generalised version of the (α,β)-k-Feature Set problem. We illustrate the performance of this new methodology via a challenging meta-analysis task involving six prostate cancer microarray datasets. The results are then compared to the popular RankProd meta-analysis tool and to what can be obtained by analysing the individual datasets by statistical and combinatorial methods alone.

Results

Application of the integrated method resulted in a more informative signature than the rank-based meta-analysis or individual dataset results, and overcomes problems arising from real world datasets. The set of genes identified is highly significant in the context of prostate cancer. The method used does not rely on homogenisation or transformation of values to a common scale, and at the same time is able to capture markers associated with subgroups of the disease.

A new target region for changing the substrate specificity of amine transaminases

(R)-stereospecific amine transaminases (R-ATAs) are important biocatalysts for the production of (R)-amine compounds in a strict stereospecific manner. An improved R-ATA, ATA-117-Rd11, was successfully engineered for the manufacture of sitagliptin, a widely used therapeutic agent for type-2 diabetes. The effects of the individual mutations, however, have not yet been demonstrated due to the lack of experimentally determined structural information. Here we describe three crystal structures of the first isolated R-ATA, its G136F mutant and engineered ATA-117-Rd11, which indicated that the mutation introduced into the 136^th residue altered the conformation of a loop next to the active site, resulting in a substrate-binding site with drastically modified volume, shape, and surface properties, to accommodate the large pro-sitagliptin ketone. Our findings provide a detailed explanation of the previously reported molecular engineering of ATA-117-Rd11 and propose that the loop near the active site is a new target for the rational design to change the substrate specificity of ATAs.

Binding mechanism of nine N-phenylpiperazine derivatives and α1A-adrenoceptor using site-directed molecular docking and high performance affinity chromatography

Investigating the binding mechanism of α_1A-adrenoceptor and its specific ligands by affinity chromatography.

Efficacy and Safety of the Selective α1A-Adrenoceptor Blocker Silodosin for Severe Lower Urinary Tract Symptoms Associated With Benign Prostatic Hyperplasia: A Prospective, Single-Open-Label, Multicenter Study in Korea

Purpose

To evaluate the efficacy and safety of silodosin 8 mg once daily in a 12-week treatment of subjects with severe lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH).

Materials and Methods

A total of 100 subjects from 10 urology centers in Korea were included in this study. The inclusion criteria were as follows: age ≥50 years, International Prostate Symptom Score (IPSS) ≥20, quality of life (QoL) score ≥3, urine volume ≥120 mL and maximal urinary flow rate (Qmax) <15 mL/s, and postvoid residual volume (PVR) <100 mL. We assessed the improvement of LUTS with change in IPSS, QoL score, Qmax, PVR, and adverse events at baseline and 4 and 12 weeks after treatment with silodosin 8 mg once daily.

Results

The IPSS values were 23.27±3.34, 15.89±6.26, and 13.80±6.31 at baseline, 4, and 12 weeks, respectively, with significant improvements (p<0.0001, p=0.0214, respectively). QoL scores were 4.44±0.85, 3.38±1.20, and 3.04±1.20 at baseline, 4, and 12 weeks, respectively, and the differences were statistically significant (p<0.0001). There was a significant difference in Qmax between baseline and 12 weeks (p<0.0001) but not in PVR (p=0.9404) during the clinical trial. The most frequent adverse event in this study was ejaculation failure with 13 cases. However, no subject dropped out because of ejaculation failure, and in 12 of the 13 cases it was fully resolved without further treatment.

Conclusions

Silodosin 8 mg once daily may be effective and safe in Korean patients with severe LUTS associated with BPH.

Naftopidil for the treatment of benign prostate hyperplasia: a systematic review

OBJECTIVES

The aim of the study was to systematically review the effects of the adrenoreceptor A1D antagonist naftopidil in the management of lower urinary tract symptoms (LUTS).

METHODS

A structured and comprehensive MEDLINE search was conducted for original articles, reviews, and metanalyses assessing the clinical pharmacology as well as the safety of naftopidil in the treatment of LUTS secondary to BPH. English-language publications dating from 1950 to 2013 were considered.

RESULTS

In the considered timeframe, 14 randomized clinical trials (RCT) were reported. Overall, the outcome measures assessed in the various reports included in the present review were changes from baseline in: International Prostate Symptom Score (IPSS), quality of life (QoL) score, maximum urinary flow rate (Qmax), residual volume (PVR), and adverse effects. Although additional well designed, worldwide, placebo-controlled and randomized studies are necessary to confirm the long-term outcomes of naftopidil pharmacotherapy, current data suggest that naftopidil administration in BPH patients provides comparable improvements in total IPSS, QoL, and urinary symptoms from baseline relative to 0.2 mg/d tamsulosin and 8 mg/d silodosin. However, improvements in Qmax are generally less with naftopidil than with tamsulosin. Reported adverse effects related to naftopidil administration are negligible and usually mild.

CONCLUSION

It remains unknown whether the data reported on naftopidil in the Japanese population are applicable in symptomatic BPH patients from western countries given that: (1) no English-language clinical trials have compared naftopidil to placebo in Western countries; (2) all clinical trials available were carried out in Japan; (3) in the comparative studies with tamsulosin, the dose of this drug was lower than the recommended dose in Western countries; (4) no data from long-term clinical trials evaluating drug safety beyond 18 weeks.

[Evolution of lower urinary tract symptoms under silodosin: factors influencing patients' satisfaction]

The objective of this study was to analyze the efficacy and safety of silodosin in patients with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) in current urologic practice.

METHOD

This was a prospective observational study conducted by 272 urologists on patients treated by silodosin for BPH. The parameters evaluated were the weighted IPSS score, the IPSS question 8 related to quality of life, the USP score and the Athens Insomnia Scale (AIS) measured at treatment initiation and after 3 months.

RESULTS

Nine hundred and fourteen patients whose average age was 66 years with LUTS for 3.3 years were analyzed. After 3 months of treatment, a significant decrease in IPSS (from 16.2 ± 6.1 to 9.7 ± 5.5, P<0.0001) and USP score (from 10.6 ± 5.1 to 6 0 ± 4.6, P<0.0001) were observed, quality of life (from 67.1% to 14.4% of unsatisfied patients, P<0.0001) and sleep were significantly improved (from 49.2% to 28.9% patients with insomnia, P<0.0001). Among the patients, 21.2% experienced at least one adverse event. The most frequent were abnormal ejaculation (17.2%). And 7.1% discontinued the treatment for this reason. After 3 months of treatment silodosin was continued in 86.9% of patients.

CONCLUSION

This large study confirmed the efficacy of silodosin in LUTS associated with BPH with a safety profile that does not affect patient satisfaction.

MR imaging of the prostate and adjacent anatomic structures before, during, and after ejaculation: qualitative and quantitative evaluation

PURPOSE

To determine the possibility of obtaining high-quality magnetic resonance (MR) images before, during, and immediately after ejaculation and detecting measurable changes in quantitative MR imaging parameters after ejaculation.

MATERIALS AND METHODS

In this prospective, institutional review board-approved, HIPAA-compliant study, eight young healthy volunteers (median age, 22.5 years), after providing informed consent, underwent MR imaging while masturbating to the point of ejaculation. A 1.5-T MR imaging unit was used, with an eight-channel surface coil and a dynamic single-shot fast spin-echo sequence. In addition, a quantitative MR imaging protocol that allowed calculation of T1, T2, and apparent diffusion coefficient (ADC) values was applied before and after ejaculation. Volumes of the prostate and seminal vesicles (SV) were calculated by using whole-volume segmentation on T2-weighted images, both before and after ejaculation. Pre- and postejaculation changes in quantitative MR parameters and measured volumes were evaluated by using the Wilcoxon signed rank test with Bonferroni adjustment.

RESULTS

There was no significant change in prostate volumes on pre- and postejaculation images, while the SV contracted by 41% on average (median, 44.5%; P = .004). No changes before and after ejaculation were observed in T1 values or in T2 and ADC values in the central gland, while T2 and ADC values were significantly reduced in the peripheral zone by 12% and 14%, respectively (median, 13% and 14.5%, respectively; P = .004).

CONCLUSION

Successful dynamic MR imaging of ejaculation events and the ability to visualize internal sphincter closure, passage of ejaculate, and significant changes in SV volumes were demonstrated. Significant changes in peripheral zone T2 and ADC values were observed.

Silodosin in the management of lower urinary tract symptoms as a result of benign prostatic hyperplasia: who are the best candidates

BACKGROUND

As the clinical effects of the available α1-adrenoceptors (ARs) blockers are usually considered comparable for treatment in patients suffering from lower urinary tract symptoms (LUTS) secondary to prostatic enlargement, officially recognised guidelines do not make specific recommendations regarding the choice of which agent should be considered according to the patient's characteristics.

AIM

To analyse data supporting the use of silodosin, a highly selective once-daily dosing α1-ARs blocker, in different daily clinical practice scenarios.

MATERIALS AND METHODS

A structured literature review was performed using data retrieved from articles assessing the role of silodosin in the management of LUTS secondary to benign prostatic hyperplasia (BPH). A literature search of English language publications was performed using MEDLINE(®) and Web of Science from 2000 to 2012 using the terms LUTS; BPH; silodosin; α1-ARs blockers. The papers with the highest level of evidence were identified and represent the basis of the present review.

RESULTS

Available data coming from basic research analyses, randomised trials and prospective studies showed that silodosin is efficacious for the initial management of patients with LUTS. Clinical developmental safety data from patients receiving silodosin with concomitant antihypertensive therapy do not indicate an increase in risk of orthostatic hypotension. In this context, a recent study demonstrated that silodosin can be safely administered to patients who are consensually assuming phosphodiesterase type 5 inhibitors. A recent randomised crossover study comparing the efficacy of silodosin and tamsulosin in patients with LUTS showed that further significant improvement was observed after switching to silodosin treatment, while worsening or little improvement was observed after switching to tamsulosin treatment. Preliminary results seem to demonstrate a potential role of silodosin in the treatment of chronic prostatitis/chronic pelvic pain syndrome and to facilitate ureteral stone passage, as well.

DISCUSSION

When considering the above cited pharmacological and clinical characteristics of the drug, silodosin can be considered in the following clinical scenario: patients suffering from moderate-severe nocturia, patients with low normal blood pressure levels and patients concomitantly treated with antihypertensive medications, patients concomitantly treated with phosphodiesterase type 5 inhibitors, patients not satisfied (for efficacy or tolerability) with previous treatment with other α1-ARs blockers.

CONCLUSION

Silodosin is efficacious for the initial management of patients with LUTS. Silodosin has a good cardiovascular safety profile and can be considered an option in patients with cardiovascular co-morbidities. It seems to be especially beneficial in patients with nocturia alone or presenting with the symptomatic trial nocturia-frequency-incomplete emptying. Patients on phosphodiesterase type 5 inhibitors treatment can be safely managed with silodosin.

Noradrenaline induces binding of Clathrin light chain A to α1-adrenoceptors in the human prostate

BACKGROUND

Binding of clathrins or caveolin to G protein-coupled receptors may induce post-translational modifications of receptor function. Receptor regulation by clathrin requires cofactors ADP-ribosylation factor 6 (ARF6) and adaptin, while dynamin is required for clathrin- and caveolin-dependent mechanisms.

OBJECTIVE

To investigate the expression and α1-adrenoceptor binding of clathrins, caveolin, and their cofactors in the human prostate.

METHODS

Prostate tissue was obtained from radical prostatectomy. Expression of clathrin heavy chain (HC), clathrin light chain A and B (LCA, LCB), caveolin-1, ARF6, β-adaptin, and dynamin-2 was studied by RT-PCR, Western blot, immunohistochemistry, and fluorescence staining. Interaction of α1A-adrenoceptors with clathrins and caveolin-1 was studied by coimmunoprecipitation.

RESULTS

mRNA and protein expression of clathrin HC, LCA, LCB, caveolin-1, dynamin-2, and β-adaptin was detected in prostate tissues of each patient. Immunohistochemistry demonstrated the expression of clathrin HC, LCA, LCB, caveolin, dynamin, and β-adaptin in stromal cells. Immunoreactivity for these proteins colocalized with α-smooth muscle actin and α1A-adrenoceptors in double fluorescence staining. Coimmunoprecipitation demonstrated that α1A-adrenoceptors in prostate tissue interact with clathrin HC and LCB under resting conditions, but not with caveolin-1. Stimulation of prostate tissues with noradrenaline (30 µM) in vitro induced binding of clathrin LCA to α1A-adrenoceptors.

CONCLUSIONS

The prostatic α1-adrenoceptor population is at least partially bound to clathrin HC and LCB. Upon receptor activation, prostate α1A-adrenoceptors bind clathrin LCA. This points to a new concept of post-translational α1-adrenoceptor regulation in the prostate, which includes receptor interaction with accessory binding partners.

Silodosin is effective for treatment of LUTS in men with BPH: a systematic review

The aim of this study was to systematically review the evidence on the efficacy and safety of silodosin treatments on lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH) from randomized controlled trials. We searched PubMed (1966-December 2011), Embase (1974-December 2011) and the Cochrane Library Database (2011, Issue 12). The assessed outcome measures were the change from baseline for the International Prostate Symptom Score (IPSS), quality of life (QoL) score, peak urine maximum flow rate (Q(max)), QoL related to urinary symptoms and adverse effects. Two authors independently assessed the study quality and extracted data. All data were analysed using RevMan 5.1. The meta-analysis included four randomized controlled trials with a total of 2504 patients. The study durations were each 12 weeks. At the follow-up end points, the pooled results showed that the change from baseline for the silodosin group was significantly higher than the placebo group for the IPSS, QoL score and Q(max)(mean difference (MD)=-2.78, P<0.00001; MD=-0.42, P=0.004; MD=1.17, P<0.00001,respectively) and patients felt more satisfied with QoL related to urinary symptoms in the silodosin group than the placebo group. Ejaculation disorder was the most commonly reported adverse effect. The pooled results also showed that the silodosin group was superior to the 0.2 mg tamsulosin group with respect to the IPSS and QoL score (IPSS: MD=-1.14, P=0.02; QoL score: MD=-0.26, P=0.02) and inferior to the 0.2 mg tamsulosin group with respect to Q(max) (MD=-0.85, P=0.01). In contrast, there was no significant difference in the incidence of ejaculation disorder and dizziness between the silodosin and 0.2 mg tamsulosin groups. The current meta-analysis suggested that silodosin is an effective therapy for LUTS in men with BPH and is not inferior to 0.2 mg tamsulosin.

Inhibition of adrenergic human prostate smooth muscle contraction by the inhibitors of c-Jun N-terminal kinase, SP600125 and BI-78D3

BACKGROUND AND PURPOSE α(1) -Adrenoceptor-induced contraction of prostate smooth muscle is mediated by calcium- and Rho kinase-dependent mechanisms. In addition, other mechanisms, such as activation of c-jun N-terminal kinase (JNK) may be involved. Here, we investigated whether JNK participates in α(1)-adrenoceptor-induced contraction of human prostate smooth muscle. EXPERIMENTAL APPROACH Prostate tissue was obtained from patients undergoing radical prostatectomy. Effects of the JNK inhibitors SP600125 (50 µM) and BI-78D3 (30 µM) on contractions induced by phenylephrine, noradrenaline and electric field stimulation (EFS) were studied in myographic measurements. JNK activation by noradrenaline (30 µM) and phenylephrine (10 µM), and the effects of JNK inhibitors of c-Jun phosphorylation were assessed by Western blot analyses with phospho-specific antibodies. Expression of JNK was studied by immunohistochemistry and fluorescence double staining. KEY RESULTS The JNK inhibitors SP600125 and BI-78D3 reduced phenylephrine- and noradrenaline-induced contractions of human prostate strips. In addition, SP600125 reduced EFS-induced contraction of prostate strips. Stimulation of prostate tissue with noradrenaline or phenylephrine in vitro resulted in activation of JNK. Incubation of prostate tissue with SP600125 or BI-78D3 reduced the phosphorylation state of c-Jun. Immunohistochemical staining demonstrated the expression of JNK in smooth muscle cells of human prostate tissue. Fluorescence staining showed that α(1A)-adrenoceptors and JNK are expressed in the same cells. CONCLUSIONS AND IMPLICATIONS Activation of JNK is involved in α(1)-adrenoceptor-induced prostate smooth muscle contraction. Models of α(1)-adrenoceptor-mediated prostate smooth muscle contraction should include this JNK-dependent mechanism.

Various treatment options for benign prostatic hyperplasia: A current update

In benign prostatic hyperplasia (BPH) there will be a sudden impact on overall quality of life of patient. This disease occurs normally at the age of 40 or above and also is associated with sexual dysfunction. Thus, there is a need of update on current medications of this disease. The presented review provides information on medications available for BPH. Phytotherapies with some improvements in BPH are also included. Relevant articles were identified through a search of the English-language literature indexed on MEDLINE, PUBMED, Sciencedirect and the proceedings of scientific meetings. The search terms were BPH, medications for BPH, drugs for BPH, combination therapies for BPH, Phytotherapies for BPH, Ayurveda and BPH, BPH treatments in Ayurveda. Medications including watchful waitings, Alpha one adrenoreceptor blockers, 5-alpha reductase inhibitors, combination therapies including tamsulosin-dutasteride, doxazosin-finasteride, terazosin-finasteride, tolterodine-tamsulosin and rofecoxib-finasteride were found. Herbal remedies such as Cernilton, Saxifraga stolonifera, Zi-Shen Pill (ZSP), Orbignya speciosa, Phellodendron amurense, Ganoderma lucidum, Serenoa Repens, pumpkin extract and Lepidium meyenii (Red Maca) have some improvements on BPH are included. Other than these discussions on Ayurvedic medications, TURP and minimally invasive therapies (MITs) are also included. Recent advancements in terms of newly synthesized molecules are also discussed. Specific alpha one adrenoreceptor blockers such as tamsulosin and alfuzosin will remain preferred choice of urologists for symptom relief. Medications with combination therapies are still needs more investigation to establish as preference in initial stage for fast symptom relief reduced prostate growth and obviously reduce need for BPH-related surgery. Due to lack of proper evidence Phytotherapies are not gaining much advantage. MITs and TURP are expensive and are rarely supported by healthcare systems.

Non-inferiority of silodosin to tamsulosin in treating patients with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH)

What's known on the subject? and What does the study add? Silodosin administered by 4 mg twice daily is as effective as tamsulosin 0.2 mg daily in treating patients with LUTS associated with BPH. Relative to tamsulosin, silodosin has less cardiovascular side effects as judged by the minimal changes of blood pressure and pulse rats after treatment.

OBJECTIVE

• To test the hypothesis that the efficacy of silodosin would not be inferior to tamsulosin in treating patients with lower urinary tract symptoms associated with benign prostate hyperplasia (BPH).

PATIENTS AND METHODS

• At nine medical centres, 209 patients with an International Prostate Symptom Score (IPSS) of ≥13 were randomized to silodosin (4 mg twice daily) or tamsulosin (0.2 mg once daily) for 12 weeks. • The primary efficacy measure was the mean change from baseline to endpoint in IPSS. • The non-inferiority margin of the IPSS change was set at 1.0. • Secondary efficacy measures included change in maximal urinary flow rate (Q(max)) and health-related quality of life (HRQL) score.

RESULTS

• Of the 170 (81.3%) patients who completed the study, 86.2% in the silodosin group vs 81.9% in the tamsulosin group achieved a ≥25% decrease in IPSS (P= 0.53). • The mean difference (silodosin minus tamsulosin) in IPSS change from baseline was -0.60 (95% confidence interval -2.15, 0.95), inferring the non-inferiority of silodosin to tamsulosin. • The mean changes in the Q(max) and HRQL score from baseline were comparable between the groups (both, P > 0.05). Although patients receiving silodosin had a significantly higher incidence of abnormal ejaculation (9.7% vs tamsulosin 1.0%, P= 0.009), only 1.9% discontinued treatment. • Tamsulosin treatment resulted in a significant reduction in mean systolic blood pressure (-4.2 mmHg, within-group P= 0.004) relative to the negligible change of silodosin (-0.1 mmHg, within-group P= 0.96)

CONCLUSION

• The trial shows the non-inferiority of silodosin 4 mg twice daily to tamsulosin 0.2 mg once daily in patients with symptoms of BPH.

Urological Disorders in Men

Urinary incontinence (UI) and benign prostatic hyperplasia (BPH) are 2 common urogenital problems in men. UI is associated with involuntary leakage of urine and lower urinary tract symptoms (LUTS) of urgency, frequency, and nocturia. Types of UI include functional, urge, stress, and overflow. Treatment for UI is based on the type of incontinence, patient-specific factors, and treatment preferences of both patients and health care providers. Options for the management of UI include environmental modifications, disposable incontinence products, pelvic floor exercises, pharmacotherapy, surgically implanted devices, and intermittent catheterization. BPH may be also associated with LUTS. Patient symptoms, assessed with a measurement tool such as the American Urological Association Symptom Index (AUASI), serve as the basis for determining treatment. Management approaches for BPH include pharmacotherapy, surgery, and minimally invasive procedures. Anticholinergic drugs as well as α-receptor antagonists and 5-α reductase inhibitors, either alone or in combination, are effective and useful for LUTS unresponsive to traditional pharmacotherapy. Transurethral resection of the prostate (TURP) can eliminate symptoms of BPH but is associated with relatively more complications than other available surgical and minimally invasive procedures.

α(1)-Adrenoceptors in the urinary tract

α(1)-Adrenoceptors have been identified and characterized extensively by functional, radioligand-binding, and molecular biological techniques. Molecular clones have been isolated for three α(1)-subtypes (α(1a), α(1b), and α(1d)), and these subtypes are also functionally characterized. α(1)-Adrenoceptors are present in the prostate, urethra, bladder (urothelium, smooth muscle, and afferent nerves), ureter, vas deferens, peripheral ganglia, nerve terminals, vascular tissues, and central nervous system (CNS), and they could all potentially influence overall urinary function and contribute to both the therapeutic and adverse effects of α(1)-adrenoceptor antagonists in patients with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). This review aimed to discuss the relevant physiological and pharmacological roles and molecular biology of α(1)-adrenoceptor subtypes in the prostate, urethra, bladder, ureter, and CNS.