UK practice for penile prosthesis surgery: baseline analysis of the British Association of Urological Surgeons (BAUS) Penile Prosthesis Audit

Objectives: To undertake a prospective multicentre national audit of penile prosthesis practice in the UK over a 3‐year period. Patients and Methods: Data were submitted by urological surgeons as part of the British Association of Urological Surgeons Penile Prosthesis National Audit. Patients receiving a penile prosthesis (inflatable or malleable) were included as part of a prospective registry over a 3‐year period. Data were validated and then analysed using a software package (Tableau). Results: A total of 1071 penile prosthesis procedures were included from 22 centres. The three commonest aetiological factors for erectile dysfunction were diabetes, prostate surgery and Peyronie's disease. Of the recorded data, inflatable penile prostheses were the commonest devices implanted, with 665 devices used (62.1%), whereas malleable prostheses accounted for 14.2% of the implants. Recorded intra‐operative complications included urethral injury (0.7%, n = 7), corporal perforation (1.1%, n = 12) and cross‐over (0.6%, n = 6). Known postoperative complications were recorded in 9.8% of patients (74/752), with the two most frequently reported being postoperative penile pain (n = 11) and scrotal haematoma (n = 14). Conclusion: This baseline analysis is the largest prospective registry of penile prostheses procedures to date. The data show that, over the 3‐year collection period in the UK, there are now fewer surgeons performing the procedure, together with a reduction in the number of centres. Peri‐operative complications were infrequent, and the rate of implant abortion (e.g. as a result of urethral injury) was very low. Further follow‐up data will be required to publish long‐term outcomes and patient satisfaction

Treatment of Peyronie's Disease With Collagenase Clostridium histolyticum and Vacuum Therapy: A Randomized, Open-Label Pilot Study

BACKGROUND: Collagenase Clostridium histolyticum (CCH) is indicated for the treatment of penile curvature in adult men with Peyronie's disease (PD) with palpable plaque and curvature deformity of at least 30° at the start of therapy. AIM: To evaluate the efficacy and safety of CCH plus vacuum-pump therapy with and without penile modeling for the management of PD. METHODS: Adult men with PD and penile curvature of at least 30° were randomly assigned to receive CCH 0.58 mg plus vacuum therapy alone (n = 15) or with penile plaque modeling (n = 15). Patients received no more than four treatment cycles (cycle = ∼6-week duration), each consisting of two intralesional injections of CCH administered 24 to 72 hours apart. Vacuum therapy was applied twice daily from 14 days after the second injection of each cycle until the following cycle. Modeling was performed 24 to 72 hours after the second injection of each cycle. OUTCOMES: The primary end point was change in penile curvature from baseline to week 36; additional end points included changes in Peyronie's Disease Questionnaire (PDQ) domain scores, composite response (≥20% decrease in penile curvature and decrease in PDQ bother score ≥ 1 point), and global response (small but important, moderate, or much improvement in the Global Assessment of PD). RESULTS: At week 36, improvement in penile curvature from baseline was similar in the two groups (mean change from baseline = -23.7° [SD = 10.9] for CCH + vacuum + modeling and -23.3° [SD = 7.2] for CCH + vacuum; between-group difference = -0.3°, 95% CI = -7.3 to 6.6). Improvements in most PDQ domains, including bother, were observed from baseline to week 36 in the two groups. Most patients were composite (66.7% and 84.6% with CCH + vacuum + modeling and CCH + vacuum, respectively) and global (86.7% and 92.3%, respectively) responders. The most common adverse events were penile contusion, penile swelling, and penile pain. CLINICAL IMPLICATIONS: Vacuum-pump therapy administered alone or in combination with modeling after CCH treatment could improve PD symptoms. STRENGTHS AND LIMITATIONS: This was a pilot study with a small sample and limited follow-up duration. CONCLUSION: CCH and vacuum-pump therapy (alone or combined with modeling) could be an appropriate consideration for men with PD and warrants further investigation

Dynamic variability of the phytoplankton electron requirement for carbon fixation in eastern Australian waters

© 2019 Elsevier B.V. Fast Repetition Rate fluorometry (FRRf) generates high-resolution measures of phytoplankton primary productivity as electron transport rates (ETRs). How ETRs scale to corresponding inorganic carbon (C) uptake rates (the so-called electron requirement for carbon fixation, Φe,C), inherently describes the extent and effectiveness with which absorbed light energy drives C-fixation. However, it remains unclear whether and how Φe,C follows predictable patterns for oceanographic datasets spanning physically dynamic, and complex, environmental gradients. We utilise a unique high-throughput approach, coupling ETRs and 14C-incubations to produce a semi-continuous dataset of Φe,C (n = 80), predominantly from surface waters, along the Australian coast (Brisbane to the Tasman Sea), including the East Australian Current (EAC). Environmental conditions along this transect could be generally grouped into cooler, more nutrient-rich waters dominated by larger size-fractionated Chl-a (>10 μm) versus warmer nutrient-poorer waters dominated by smaller size-fractionated Chl-a (<2 μm). Whilst Φe,C was higher for warmer water samples, environmental conditions alone explained <20% variance of Φe,C, and changes in predominant size-fraction(s) distributions of Chl-a (biomass) failed to explain variance of Φe,C. Instead, normalised Stern-Volmer non-photochemical quenching (NPQNSV = F0′/Fv′) was a better predictor of Φe,C, explaining ~55% of observed variability. NPQNSV is a physiological descriptor that accounts for changes in both long-term driven acclimation in non-radiative decay, and quasi-instantaneous PSII downregulation, and thus may prove a useful predictor of Φe,C across physically-dynamic regimes, provided the slope describing their relationship is predictable. We also consider recent advances in fluorescence-based corrections to evaluate the potential role of baseline fluorescence (Fb) in contributing to overestimation of Φe,C and the correlation between Φe,C and NPQNSV – in doing so, we highlight the need for Fb corrections for future field-based assessments of Φe,C

Divergence of photosynthetic strategies amongst marine diatoms.

Marine phytoplankton, and in particular diatoms, are responsible for almost half of all primary production on Earth. Diatom species thrive from polar to tropical waters and across light environments that are highly complex to relatively benign, and so have evolved highly divergent strategies for regulating light capture and utilization. It is increasingly well established that diatoms have achieved such successful ecosystem dominance by regulating excitation energy available for generating photosynthetic energy via highly flexible light harvesting strategies. However, how different light harvesting strategies and downstream pathways for oxygen production and consumption interact to balance excitation pressure remains unknown. We therefore examined the responses of three diatom taxa adapted to inherently different light climates (estuarine Thalassioisira weissflogii, coastal Thalassiosira pseudonana and oceanic Thalassiosira oceanica) during transient shifts from a moderate to high growth irradiance (85 to 1200 μmol photons m-2 s-1). Transient high light exposure caused T. weissflogii to rapidly downregulate PSII with substantial nonphotochemical quenching, protecting PSII from inactivation or damage, and obviating the need for induction of O2 consuming (light-dependent respiration, LDR) pathways. In contrast, T. oceanica retained high excitation pressure on PSII, but with little change in RCII photochemical turnover, thereby requiring moderate repair activity and greater reliance on LDR. T. pseudonana exhibited an intermediate response compared to the other two diatom species, exhibiting some downregulation and inactivation of PSII, but high repair of PSII and induction of reversible PSII nonphotochemical quenching, with some LDR. Together, these data demonstrate a range of strategies for balancing light harvesting and utilization across diatom species, which reflect their adaptation to sustain photosynthesis under environments with inherently different light regimes

Taxonomic variability in the electron requirement for carbon fixation across marine phytoplankton.

Fast Repetition Rate fluorometry (FRRf) has been increasingly used to measure marine primary productivity by oceanographers to understand how carbon (C) uptake patterns vary over space and time in the global oceans. As FRRf measures electron transport rates through photosystem II (ETRPSII ), a critical, but difficult-to-predict conversion factor termed the "electron requirement for carbon fixation" (Φe,C ) is needed to scale ETRPSII to C-fixation rates. Recent studies have generally focused on understanding environmental regulation of Φe,C , while taxonomic control has been explored by only a handful of laboratory studies encompassing a limited diversity of phytoplankton species. We therefore assessed Φe,C for a wide range of marine phytoplankton (n=17 strains) spanning multiple taxonomic and size-classes. Data mined from previous studies were further considered to determine whether Φe,C variability could be explained by taxonomy versus other phenotypic traits influencing growth and physiological performance (e.g., cell size). We found that Φe,C exhibited considerable variability (~4-10 mol e- · [mol C]-1 ), and was negatively correlated with growth rate (R2 = 0.7, p < 0.01). Diatoms exhibited a lower Φe,C compared to chlorophytes during steady-state, nutrient-replete growth. Inclusion of meta-analysis data did not find significant relationships between Φe,C and class, or growth rate, although confounding factors inherent to methodological inconsistencies between studies likely contributed to this. Knowledge of empirical relationships between Φe,C and growth rate coupled with recent improvements in quantifying phytoplankton growth rates in-situ, facilitate up-scaling of FRRf campaigns to routinely derive Φe,C needed to assess ocean C-cycling

Appendix to "Approximating perpetuities"

An algorithm for perfect simulation from the unique solution of the distributional fixed point equation $Y=_d UY + U(1-U)$ is constructed, where $Y$ and $U$ are independent and $U$ is uniformly distributed on $[0,1]$. This distribution comes up as a limit distribution in the probabilistic analysis of the Quickselect algorithm. Our simulation algorithm is based on coupling from the past with a multigamma coupler. It has four lines of code

Impact of nitrogen availability upon the electron requirement for carbon fixation in Australian coastal phytoplankton communities

© 2018 Association for the Sciences of Limnology and Oceanography Nitrogen (N) availability affects phytoplankton photosynthetic performance and regulates marine primary production (MPP) across the global coast and oceans. Bio-optical tools including Fast Repetition Rate fluorometry (FRRf) are particularly well suited to examine MPP variability in coastal regions subjected to dynamic spatio-temporal fluctuations in nutrient availability. FRRf determines photosynthesis as an electron transport rate through Photosystem II (ETRPSII), requiring knowledge of an additional parameter, the electron requirement for carbon fixation (KC), to retrieve rates of CO2-fixation. KC strongly depends upon environmental conditions regulating photosynthesis, yet the importance of N-availability to this parameter has not been examined. Here, we use nutrient bioassays to isolate how N (relative to other macronutrients P, Si) regulates KC of phytoplankton communities from the Australian coast during summer, when N-availability is often highly variable. KC consistently responded to N-amendment, exhibiting up to a threefold reduction and hence an apparent increase in the efficiency with which electrons were used to drive C-fixation. However, the process driving this consistent reduction was dependent upon initial conditions. When diatoms dominated assemblages and N was undetectable (e.g., post bloom), KC decreased predominantly via a physiological adjustment of the existing community to N-amendment. Conversely, for mixed assemblages, N-addition achieved a similar reduction in KC through a change in community structure toward diatom domination. We generate new understanding and parameterization of KC that is particularly critical to advance how FRRf can be applied to examine C-uptake throughout the global ocean where nitrogen availability is highly variable and thus frequently limits primary productivity

Surgical Techniques for Managing Post-prostatectomy Erectile Dysfunction

PURPOSE OF REVIEW: Due to the increasing numbers of radical prostatectomies (RP) performed for prostate cancer, a substantial number of patients are now suffering from post-operative erectile dysfunction (ED). The aim of this study is to summarize the current literature on surgical techniques for managing post-prostatectomy erectile dysfunction. RECENT FINDINGS: The PubMed database was searched for English-language articles published up to Jan 2017 using the following search terms: “prostatectomy AND erectile dysfunction”, “prostatectomy AND penile prostheses”, and “prostatectomy AND penile implants”. All of the studies that evaluated medical treatment were excluded. In the last few decades, the understanding of the anatomy of the male pelvis and prostate has improved. This has led to significant changes in the nerve-sparing radical prostatectomy techniques, with the aim of preserving post-surgical erectile function (EF). In this scenario, the prostate vascular supply and the anatomy of the neurovascular bundles have a central role. Penile prosthesis implantation is considered the third-line treatment option for RP ED patients, and they have been reported to be a very successful treatment with the highest patient satisfaction rate. SUMMARY: Considering the failure of penile rehabilitation, and the lack of evidence for accessory pudendal artery (APA) preservation and nerve graft, nerve-sparing surgery and penile prostheses represent, today, the only methods to permanently and definitively preserve or erectile function after RP

Paraganglioma of the Spermatic Cord: Case Report and Review of the Literature

Paragangliomas rarely involve the genitourinary tract. We present a case of a paraganglioma arising from the spermatic cord and review the literature on the topic

Roadmaps and Detours: Active Chlorophyll- a Assessments of Primary Productivity Across Marine and Freshwater Systems

Copyright © 2018 American Chemical Society. Assessing phytoplankton productivity over space and time remains a core goal for oceanographers and limnologists. Fast Repetition Rate fluorometry (FRRf) provides a potential means to realize this goal with unprecedented resolution and scale yet has not become the "go-to" method despite high expectations. A major obstacle is difficulty converting electron transfer rates to equivalent rates of C-fixation most relevant for studies of biogeochemical C-fluxes. Such difficulty stems from methodological inconsistencies and our limited understanding of how the electron requirement for C-fixation (φ e,C ) is influenced by the environment and by differences in the composition and physiology of phytoplankton assemblages. We outline a "roadmap" for limiting methodological bias and to develop a more mechanistic understanding of the ecophysiology underlying φ e,C . We 1) re-evaluate core physiological processes governing how microalgae invest photosynthetic electron transport-derived energy and reductant into stored carbon versus alternative sinks. Then, we 2) outline steps to facilitate broader uptake and exploitation of FRRf, which could transform our knowledge of aquatic primary productivity. We argue it is time to 3) revise our historic methodological focus on carbon as the currency of choice, to 4) better appreciate that electron transport fundamentally drives ecosystem biogeochemistry, modulates cell-to-cell interactions, and ultimately modifies community biomass and structure