Phase I and phase II clinical trials for the treatment of male sexual dysfunction-a systematic review of the literature

Long-term consequences of bilateral cavernous crush injury in normal and diabetic rats: a functional study

A recent statement from the European-Society-for-Sexual-Medicine has highlighted the limitations of using the rat model for nerve-sparing prostatectomy. The use of young rats with no comorbidities and the early evaluation of the erectile function (EF) are deemed a source of bias. Our aim was to evaluate the long-term consequences in EF of bilateral nerve cavernous crush- injury (BNCI) in type 1 diabetic (DM) rats 30-male/12-week-old rats were divided into four groups: Sham, BNCI, DM, and BNCI + DM. Sham group underwent an intraperitoneal injection (IP) of saline solution and after 1 month underwent a sham laparotomy. BNCI underwent an IP of saline solution and after 1 month to BNCI. DM underwent an IP of 60 mg/kg-1-streptozotocin (STZ) and after 1 month to a sham laparotomy. BNCI + DM underwent an IP of 60 mg/kg-1-STZ and after 1 month to BNCI. After 5 months from the induction of diabetes, all rats underwent measurement of intracorporeal pressure (ICP) and mean arterial pressure (MAP) during CN-electrostimulation. Multiple groups were compared using Kruskal-Wallis one-way analysis of variance followed by Mann-Whitney U test for post hoc comparisons. Blood glucose-level was higher (p < 0.05) in the groups with DM and BNCI + DM. After 5-months, DM and BNCI + DM also showed a lower weight compared to other groups (p < 0.05). No differences were noted in ICP/MAP between the sham and BNCI. BNCI + DM showed lower ICP/MAP compared to all the groups (p < 0.05). DM Showed lower ICP/MAP compared to Sham and BNCI (p < 0.05). BNCI in rats without comorbidities did not induce long-term erectile dysfunction (ED) suggesting a spontaneous EF recovery. BNCI in DM induced long-term ED. The results of previous short-term studies can only provide evidence on the time to recovery of spontaneous EF as to the actual EF recovery rate.

A Critical Analysis of Reporting in Systematic Reviews and Meta-Analyses in the Peyronie's Disease Literature

BACKGROUND

Despite an increasing number of publications on Peyronie's disease (PD), evidence-based clinical decision-making remains challenging due to the small number of well-designed clinical trials.

AIM

To perform a critical analysis of reporting quality in PD systematic reviews (SR) and meta-analyses (MA).

METHODS

Study protocol registration was performed on the Open Science Framework platform. In January 2021, a systematic electronic search of the Medline/PubMed, Embase, Ovid, Scopus, Joanne Briggs Institute, and Cochrane databases was performed. Search terms included "Peyronie's disease" and "systematic review OR meta-analysis OR meta-analysis." Eligibility criteria were English-language, relevance to PD and specification of "systematic review" or "meta-analysis" in the title or abstract. Oxford Center for Evidence-Based Medicine levels of evidence were used to classify original studies reviewed within each publication. Risk of bias was assessed using the ROBIS tool. Data were tabulated and reported as means with standard deviation, median with interquartile range and t-testing as appropriate. Strength of association between variables was calculated using Pearson correlation coefficient. Statistical analyses were performed on RStudio (version 1.4.1106).

OUTCOMES

Outcomes included review type, level of evidence, authorship, journal, publication date, "A MeaSurement Tool to Assess systematic Reviews" (AMSTAR-2) score and "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) score.

RESULTS

From 1974 to 2021, 340 articles were identified. After review, 17 full length articles were included. Thirteen were SR, 2 MA and 2 was combined. Significant heterogeneity was seen in evidence level of included studies. There was median 54% adherence to AMSTAR-2 criteria and 74% adherence to PRISMA criteria. Overall AMSTAR-2 confidence rating was Critically Low in 11 of 17 studies. Correlation analysis revealed very high positive association between AMSTAR 2 and PRISMA adherence (+0.95). ROBIS revealed "High" concern regarding methods used to collect data and appraise 12/17 studies (71%), and "High" concern regarding synthesis and findings in 8 of 17 studies (47%).

CLINICAL IMPLICATIONS

Many SR include markedly heterogenous levels of evidence and fail to meet accepted methodological criteria for reporting.

STRENGTHS AND LIMITATIONS

Main strengths include extensive literature review and analysis of standardized study reporting. One limitation is that aggregate scoring of AMSTAR-2 and PRISMA is not intended as primary method of quality assessment; however effect was minimized by reporting critical domains, overall quality assessments and specifics on globally poorly reported domains.

CONCLUSION

More high quality randomized controlled PD trials are necessary; SR and MA should focus on these studies alone. Bole R, Gottlich HC, Ziegelmann MJ, et al. A Critical Analysis of Reporting in Systematic Reviews and Meta-Analyses in the Peyronie's Disease Literature. J Sex Med 2022;19:629-640.

In vivo tracking on longer retention of transplanted myocardin gene-modified adipose-derived stem cells to improve erectile dysfunction in diabetic rats

BACKGROUND

Stem cell therapy has revealed a promising future for treating erectile dysfunction (ED), but the fate and curative mechanism of intracavernosal transplanted stem cells are under further exploration. This study aimed to demonstrate the effects of myocardin gene modification on improving erectile function and prolonging the retention of implanted adipose-derived stem cells (ASCs) using in vivo small animal imaging.

METHODS

ASCs were isolated, cultured, and identified by flow cytometry and osteogenic and adipogenic induction. The effects of gene modification on cell proliferation, apoptosis, and contraction were determined by CCK-8, EdU, flow cytometry, and collagen gel lattice contraction assays as well as confocal microscopy. A total of 20 normal and 60 diabetes mellitus ED to (DMED) Sprague-Dawley rats were recruited to the 7 day and 21 day groups. Each group contained subgroups of 10 rats each: the negative control (NC), DMED + ASCs plus Ad-Luc-Myocardin, DMED + ASCs plus Ad-Luc, and DMED + phosphate buffer solution (PBS) groups. Erectile function was evaluated with the intracavernosal pressure/mean arterial pressure (△ICP/MAP) ratio. In vivo small animal imaging and an EdU cell tracking strategy were introduced to detect the transplanted ASCs, and IHC and WB were performed to assess smooth muscle cell protein levels.

RESULTS

The ASCs expressed high CD29 and CD90 and scant CD45, while the multi-induction potential was verified by oil red O and alizarin red staining. Gene transfection of myocardin had no significant influence on ASC apoptosis but inhibited cell proliferation and promoted cell contraction. Myocardin combined with ASCs enhanced the therapeutic potential of ASCs for improving the △ICP/MAP ratio as well as α-SMA and calponin expression. In vivo imaging confirmed that ASCs resided within the cavernous body in 21 days, while only a few red EdU dots were detected.

CONCLUSIONS

Myocardin induced ASC differentiation towards smooth muscle-like cells and enhanced the therapeutic potential of ASCs for ameliorating ED in STZ-induced diabetic rats. Notably, in vivo small animal tracking was an effective strategy for monitoring the implanted stem cells, and this strategy might have advantages over traditional EdU assays.

Advances in stem cell therapy for erectile dysfunction

INTRODUCTION

Stem cell (SC) application is a promising area of research in regenerative medicine, with the potential to treat, prevent, and cure disease. In recent years, the number of studies focusing on SCs for the treatment of erectile dysfunction (ED) and other sexual dysfunctions has increased significantly.

AREAS COVERED

This review includes critical ED targets and preclinical studies, including the use of SCs and animal models in diabetes, aging, cavernous nerve injury, and Peyronie's disease. A literature search was performed on PubMed for English articles.

EXPERT OPINION

Combination treatment offers better results than monotherapy to improve pathological changes in diabetic ED. Regenerative medicine is a promising approach for the maintenance of sexual health and erectile function later in life. Cavernous nerve regeneration and vascular recovery employing SC treatment may be focused on radical prostatectomy-induced ED. Notwithstanding, there are a number of hurdles to overcome before SC-based therapies for ED are considered in clinical settings. Paracrine action, not cellular differentiation, appears to be the principal mechanism of action underlying SC treatment of ED. Intracavernosal injection of a single SC type should be the choice protocol for future clinical trials.