Society of Urologic Prosthetic Surgeons' Coding and Billing Position Statement on Ancillary/Adjunct Penile Prosthesis Surgical Procedures: Part I.

OBJECTIVE: To create a society position statement on common adjunct penile prosthesis (PP) procedures. While the Medicare Current Procedural Terminology code book lists descriptions of procedures, it is very brief and lacks detail in the small subspecialty of prosthetic urology. At educational/research meetings, wide variation was found in how experts in prosthetic urology code the same procedures, and need for a standardized format in billing common ancillary surgery was voiced. METHODS: A subcommittee within the Society of Urologic Prosthetic Surgeons developed a survey assessing coding options for several procedures commonly adjunct to PP placement, which was distributed in the fall of 2022. The results of the survey were used to develop consensus statements on coding adjunct PP procedures; statements were distributed among society membership and meetings for approval. RESULTS: Thirty members replied to the survey; demographics were obtained as follows: 73% were trained in a fellowship, 50% identified as university/academic practitioners, and 50% in community/private practice; and 63% respondents place more than 50 implants annually. Only 1 of the 30 respondents stated confidence in coding for these ancillary procedures. Specifically, differences in how to code curvature correction procedures were observed throughout the survey results. CONCLUSION: Only 1 in 30 prosthetic urologists expressed confidence in coding and billing of adjunct PP procedures, further confirming the need for a society position statement. Therefore, we generated a consensus society position statement on common surgeries that are adjunct to PP placement.

Using automated patch clamp electrophysiology platforms in ion channel drug discovery: an industry perspective.

INTRODUCTION: Automated patch clamp (APC) is now well established as a mature technology for ion channel drug discovery in academia, biotech and pharma companies, and in contract research organizations (CRO), for a variety of applications including channelopathy research, compound screening, target validation and cardiac safety testing. AREAS COVERED: Ion channels are an important class of drugged and approved drug targets. The authors present a review of the current state of ion channel drug discovery along with new and exciting developments in ion channel research involving APC. This includes topics such as native and iPSC-derived cells in ion channel drug discovery, channelopathy research, organellar and biologics in ion channel drug discovery. EXPERT OPINION: It is our belief that APC will continue to play a critical role in ion channel drug discovery, not only in 'classical' hit screening, target validation and cardiac safety testing, but extending these applications to include high throughput organellar recordings and optogenetics. In this way, with advancements in APC capabilities and applications, together with high resolution cryo-EM structures, ion channel drug discovery will be re-invigorated, leading to a growing list of ion channel ligands in clinical development.

New aryl and acylsulfonamides as state-dependent inhibitors of Nav1.3 voltage-gated sodium channel.

Voltage-gated sodium channels (Navs) play an essential role in neurotransmission, and their dysfunction is often a cause of various neurological disorders. The Nav1.3 isoform is found in the CNS and upregulated after injury in the periphery, but its role in human physiology has not yet been fully elucidated. Reports suggest that selective Nav1.3 inhibitors could be used as novel therapeutics to treat pain or neurodevelopmental disorders. Few selective inhibitors of this channel are known in the literature. In this work, we report the discovery of a new series of aryl and acylsulfonamides as state-dependent inhibitors of Nav1.3 channels. Using a ligand-based 3D similarity search and subsequent hit optimization, we identified and prepared a series of 47 novel compounds and tested them on Nav1.3, Nav1.5, and a selected subset also on Nav1.7 channels in a QPatch patch-clamp electrophysiology assay. Eight compounds had an IC50 value of less than 1 µM against the Nav1.3 channel inactivated state, with one compound displaying an IC50 value of 20 nM, whereas activity against the inactivated state of the Nav1.5 channel and Nav1.7 channel was approximately 20-fold weaker. None of the compounds showed use-dependent inhibition of the cardiac isoform Nav1.5 at a concentration of 30 µM. Further selectivity testing of the most promising hits was measured using the two-electrode voltage-clamp method against the closed state of the Nav1.1-Nav1.8 channels, and compound 15b displayed small, yet selective, effects against the Nav1.3 channel, with no activity against the other isoforms. Additional selectivity testing of promising hits against the inactivated state of the Nav1.3, Nav1.7, and Nav1.8 channels revealed several compounds with robust and selective activity against the inactivated state of the Nav1.3 channel among the three isoforms tested. Moreover, the compounds were not cytotoxic at a concentration of 50 µM, as demonstrated by the assay in human HepG2 cells (hepatocellular carcinoma cells). The novel state-dependent inhibitors of Nav1.3 discovered in this work provide a valuable tool to better evaluate this channel as a potential drug target.

An examination of predictive markers for successful sperm extraction procedures: a linear model and systematic review.

The authors performed a comprehensive review of current literature to create a model comparing commonly evaluated variables in male factor infertility, for example, follicle-stimulating hormone (FSH), testicular volume (TV), and testosterone (T), to better predict sperm retrieval rate (SRR). Twenty-nine studies were included, 9 with data on conventional testicular sperm extraction (cTESE) for a total of 1227 patients and 20 studies including data on microdissection testicular sperm extraction (mTESE) for a total of 4760 patients. A weighted-means value of SRR, FSH, T, and TV was created, and a weighted linear regression was then used to describe associations among SRR, type of procedure, FSH, T, and TV. In this study, weighted-means values demonstrated mTESE to be superior to cTESE with an SRR of 51.9% vs 40.1%. Multiple weighted linear regressions were created to describe associations among SRR, procedure type, FSH, T, and TV. The models showed that for every 1.19 mIU ml-1 increase in FSH, there would be a significant decrease in SRR by 1.0%. Seeking to create a more clinically relevant model, FSH values were then divided into normal, moderate elevation, and significant elevation categories (FSH <10 mIU ml-1, 10-19 mIU ml-1, and >20 mIU ml-1, respectively). For an index patient undergoing cTESE, the retrieval rates would be 57.1%, 44.3%, and 31.2% for values normal, moderately elevated, and significantly elevated, respectively. In conclusion, in a large meta-analysis, mTESE was shown to be more successful than cTESE for sperm retrievals. FSH has an inverse relationship to SRR in retrieval techniques and can alone be predictive of cTESE SRR.

Development of ASIC1a ligand-gated ion channel drug screening assays across multiple automated patch clamp platforms.

Human acid-sensing ion channels (ASIC) are ligand-gated ionotropic receptors expressed widely in peripheral tissues as well as sensory and central neurons and implicated in detection of inflammation, tissue injury, and hypoxia-induced acidosis. This makes ASIC channels promising targets for drug discovery in oncology, pain and ischemia, and several modulators have progressed into clinical trials. We describe the use of hASIC1a as a case study for the development and validation of low, medium and high throughput automated patch clamp (APC) assays suitable for the screening and mechanistic profiling of new ligands for this important class of ligand-gated ion channel. Initial efforts to expand on previous manual patch work describing an endogenous hASIC1a response in HEK cells were thwarted by low current expression and unusual pharmacology, so subsequent work utilized stable hASIC1a CHO cell lines. Ligand-gated application protocols and screening assays on the Patchliner, QPatch 48, and SyncroPatch 384 were optimized and validated based on pH activation and nM-µM potency of reference antagonists (e.g., Amiloride, Benzamil, Memantine, Mambalgin-3, A-317567, PcTx1). By optimizing single and stacked pipette tip applications available on each APC platform, stable pH-evoked currents during multiple ligand applications enabled cumulative EC50 and IC50 determinations with minimized receptor desensitization. Finally, we successfully demonstrated for the first time on an APC platform the ability to use current clamp to implement the historical technique of input resistance tracking to measure ligand-gated changes in membrane conductance on the Patchliner platform.

Y chromosome copy number variation and its effects on fertility and other health factors: a review.

The Y chromosome is essential for testis development and spermatogenesis. It is a chromosome with the lowest gene density owing to its medium size but paucity of coding genes. The Y chromosome is unique in that the majority of its structure is highly repetitive sequences, with the majority of these limited genes occurring in 9 amplionic sequences throughout the chromosome. The repetitive nature has its benefits as it can be protective against gene loss over many generations, but it can also predispose the Y chromosome to having wide variations of the number of gene copies present in these repeated sequences. This is known as copy number variation. Copy number variation is not unique to the Y chromosome but copy number variation is a well-known cause of male infertility and having effects on spermatogenesis. This is most commonly seen as deletions of the AZF sequences on the Y chromosome. However, there are other implications for copy number variation beyond just the AZF deletions that can affect spermatogenesis and potentially have other health implications. Copy number variations of TSPY1, DAZ, CDY1, RBMY1, the DYZ1 array, along with minor deletions of gr/gr, b1/b3, and b2/b3 have all be implicated in affecting spermatogenesis. UTY copy number variations have been implicated in risk for cardiovascular disease, and other deletions within gr/gr and the AZF sequences have been implicated in cancer and neuropsychiatric diseases. This review sets out to describe the Y chromosome and unique susceptibility to copy number variation and then to examine how this growing body of research impacts spermatogenesis and other health factors.

Dynamics of papillomavirus in vivo disease formation & susceptibility to high-level disinfection-Implications for transmission in clinical settings.

BACKGROUND: High-level disinfection protects tens-of-millions of patients from the transmission of viruses on reusable medical devices. The efficacy of high-level disinfectants for preventing human papillomavirus (HPV) transmission has been called into question by recent publications, which if true, would have significant public health implications. METHODS: Evaluation of the clinical relevance of these published findings required the development of novel methods to quantify and compare: (i) Infectious titres of lab-produced, clinically-sourced, and animal-derived papillomaviruses, (ii) The papillomavirus dose responses in the newly developed in vitro and in vivo models, and the kinetics of in vivo disease formation, and (iii) The efficacy of high-level disinfectants in inactivating papillomaviruses in these systems. FINDINGS: Clinical virus titres obtained from cervical lesions were comparable to those obtained from tissue (raft-culture) and in vivo models. A mouse tail infection model showed a clear dose-response for disease formation, that papillomaviruses remain stable and infective on fomite surfaces for at least 8 weeks without squames and up to a year with squames, and that there is a 10-fold drop in virus titre with transfer from a fomite surface to a new infection site. Disinfectants such as ortho-phthalaldehyde and hydrogen peroxide, but not ethanol, were highly effective at inactivating multiple HPV types in vitro and in vivo. INTERPRETATION: Together with comparable results presented in a companion manuscript from an independent laboratory, this work demonstrates that high-level disinfectants inactivate HPV and highlights the need for standardized and well-controlled methods to assess HPV transmission and disinfection. FUNDING: Advanced Sterilization Products, UK-MRC (MR/S024409/1 and MC-PC-13050) and Addenbrookes Charitable Trust.

Infectious titres of human papillomaviruses (HPVs) in patient lesions, methodological considerations in evaluating HPV infectivity and implications for the efficacy of high-level disinfectants.

BACKGROUND: Recent publications from a single research group have suggested that aldehyde-based high-level disinfectants (HLDs), such as ortho-phthalaldehyde (OPA), are not effective at inactivating HPVs and that therefore, patients may be at risk of HPV infection from medical devices. These results could have significant public health consequences and therefore necessitated evaluation of their reproducibility and clinical relevance. METHODS: We developed methods and used standardised controls to: (1) quantify the infectious levels of clinically-sourced HPVs from patient lesions and compare them to laboratory-derived HPVs, (2) evaluate experimental factors that should be controlled to ensure consistent and reproducible infectivity measurements of different HPV genotypes, and (3) determine the efficacy of select HLDs. FINDINGS: A novel focus forming unit (FFU) infectivity assay demonstrated that exfoliates from patient anogenital lesions and respiratory papillomas yielded infectious HPV burdens up to 2.7 × 103 FFU; therefore, using 2.2 × 102 to 1.0 × 104 FFU of laboratory-derived HPVs in disinfection assays provides a relevant range for clinical exposures. RNase and neutralising antibody sensitivities were used to ensure valid infectivity measures of tissue-derived and recombinant HPV preparations. HPV infectivity was demonstrated over a dynamic range of 4-5 log10; and disinfection with OPA and hypochlorite was achieved over 3 to >4 log10 with multiple genotypes of tissue-derived and recombinant HPV isolates. INTERPRETATION: This work, along with a companion publication from an independent lab in this issue, address a major public health question by showing that HPVs are susceptible to HLDs. FUNDING: Advanced Sterilization Products; US NIH (R01CA207368, U19AI084081, P30CA118100).

Broadening the differential: A case of penile pyoderma gangrenosum.

Pyoderma gangrenosum can be a challenging diagnosis for even the most experienced clinician. Misdiagnosis can lead to delays in appropriate treatment and unwarranted debridement that can increase the severity of the disease. Penile pyoderma gangrenosum (PG) is a rare presentation of this pathologic process. We describe the diagnostic workup and successful treatment of advanced penile PG in a 42-year-old male with a history of penile fracture who presented with delayed wound healing and multiple unsuccessful urologic surgeries. This case demonstrates the importance of keeping a broad differential, including PG, in order to avoid delays to appropriate care.

Prostatic irradiation-induced sexual dysfunction: A review and multidisciplinary guide to management in the radical radiotherapy era (Part II on Urological Management).

Prostate cancer is the most common malignancy in men and the second leading cause of cancer-related death in men. Radiotherapy is a curative option that is administered via external beam radiation, brachytherapy, or in combination. Sexual dysfunction is a common toxicity following radiotherapy, similar to men undergoing radical prostatectomy, but the etiology is different. The pathophysiology of radiation-induced sexual dysfunction is multi-factorial, and the toxicity is a major cause of impaired quality of life among long-term prostate cancer survivors. Management of a patient's sexual function during and after radiotherapy requires multidisciplinary coordination of care between radiation oncology, urology, psychiatry, pharmacy, and dermatology. This review provides a framework for clinicians to better understand prostatic radiotherapy-induced sexual dysfunction diagnosis, evaluation, and a patient-centered approach to toxicity preventive strategies and management.

Prostatic irradiation-induced sexual dysfunction: a review and multidisciplinary guide to management in the radical radiotherapy era (Part I defining the organ at risk for sexual toxicities).

Prostate cancer is the most common malignancy and the second leading cause of cancer-related death in men. Radiotherapy is a curative option that is administered via external beam radiation, brachytherapy, or in combination. Erectile, ejaculatory and orgasm dysfunction(s) is/are known potential and common toxicities associated with prostate radiotherapy. Our multidisciplinary team of physicians and/or scientists have written a three (3) part comprehensive review of the pathogenesis and management radiation-induced sexual dysfunction. Part I reviews pertinent anatomy associated with normal sexual function and then considers the pathogenesis of prostate radiation-induced sexual toxicities. Next, our team considers the associated radiobiological (including the effects of time, dose and fractionation) and physical (treatment planning and defining a novel Organ at Risk (OAR)) components that should be minded in the context of safe radiation treatment planning. The authors identify an OAR (i.e., the prostatic plexus) and provide suggestions on how to minimize injury to said OAR during the radiation treatment planning process.

A systematic strategy for estimating hERG block potency and its implications in a new cardiac safety paradigm.

INTRODUCTION: hERG block potency is widely used to calculate a drug's safety margin against its torsadogenic potential. Previous studies are confounded by use of different patch clamp electrophysiology protocols and a lack of statistical quantification of experimental variability. Since the new cardiac safety paradigm being discussed by the International Council for Harmonisation promotes a tighter integration of nonclinical and clinical data for torsadogenic risk assessment, a more systematic approach to estimate the hERG block potency and safety margin is needed. METHODS: A cross-industry study was performed to collect hERG data on 28 drugs with known torsadogenic risk using a standardized experimental protocol. A Bayesian hierarchical modeling (BHM) approach was used to assess the hERG block potency of these drugs by quantifying both the inter-site and intra-site variability. A modeling and simulation study was also done to evaluate protocol-dependent changes in hERG potency estimates. RESULTS: A systematic approach to estimate hERG block potency is established. The impact of choosing a safety margin threshold on torsadogenic risk evaluation is explored based on the posterior distributions of hERG potency estimated by this method. The modeling and simulation results suggest any potency estimate is specific to the protocol used. DISCUSSION: This methodology can estimate hERG block potency specific to a given voltage protocol. The relationship between safety margin thresholds and torsadogenic risk predictivity suggests the threshold should be tailored to each specific context of use, and safety margin evaluation may need to be integrated with other information to form a more comprehensive risk assessment.

Comparison of clinician and patient users of a mobile phone application to assess penile curvature in Peyronie's disease.

Assessment of Peyronie's disease with penile injection is invasive and uncomfortable. We developed a smartphone application (UWPEN) to assess penile angulation in the home environment. The purpose of this study was to compare clinician and patient measurements and assess the patient experience with UWPEN in a clinical setting. We prospectively enrolled patients with Peyronie's disease undergoing intracavernosal injection of alprostadil. Penile angulation and narrowing were then assessed by patients and clinicians using UWPEN and compared to values obtained via a goniometer and a ruler (gold standard). Measurements were compared using the Pearson correlation test. Upon completion of measurements, patients were surveyed regarding the ease of use, confidence with use, and measurement preferences. Twenty patients were enrolled in the study; two patients were excluded for poor penile turgidity after a maximum dosage of intracavernosal alprostadil. Correlation between UWPEN and gold standard measurements by patients and clinicians was R = 0.55 (p = 0.01) and R = 0.87 (p < 0.01) for dorsal measurements, R = 0.62 (p = 0.01) and R = 0.77 (p < 0.01) for lateral measurements, and R = 0.73 (p < 0.01) and R = 0.64 (p < 0.01) for girth measurements, respectively. Prior evaluation of correlation suggests a strong correlation at R = 0.8, and good correlation at R = 0.5. Overall, patients preferred using UWPEN to traditional measurements, and 75% reported UWPEN as their first preference for measurements. UWPEN enables patients to assess their disease severity with good correlation to gold standard measurements. Patients prefer mobile platforms for disease monitoring, and development of technology for disease monitoring should be a priority within the Peyronie's disease research community.

The role of Nav1.7 in human nociceptors: insights from human induced pluripotent stem cell-derived sensory neurons of erythromelalgia patients.

The chronic pain syndrome inherited erythromelalgia (IEM) is attributed to mutations in the voltage-gated sodium channel (NaV) 1.7. Still, recent studies targeting NaV1.7 in clinical trials have provided conflicting results. Here, we differentiated induced pluripotent stem cells from IEM patients with the NaV1.7/I848T mutation into sensory nociceptors. Action potentials in these IEM nociceptors displayed a decreased firing threshold, an enhanced upstroke, and afterhyperpolarization, all of which may explain the increased pain experienced by patients. Subsequently, we investigated the voltage dependence of the tetrodotoxin-sensitive NaV activation in these human sensory neurons using a specific prepulse voltage protocol. The IEM mutation induced a hyperpolarizing shift of NaV activation, which leads to activation of NaV1.7 at more negative potentials. Our results indicate that NaV1.7 is not active during subthreshold depolarizations, but that its activity defines the action potential threshold and contributes significantly to the action potential upstroke. Thus, our model system with induced pluripotent stem cell-derived sensory neurons provides a new rationale for NaV1.7 function and promises to be valuable as a translational tool to profile and develop more efficacious clinical analgesics.

Ion Channels Prominent at Key U.S. and U.K. Conferences.

A summary of the presentations featured at two key ion channel-focused events. This includes the Ion Channels in Drug Discovery XIX Satellite Meeting held at the 63rd Annual Meeting of the Biophysical Society (2019) and the Cambridge Ion Channel Symposium, cohosted by AstraZeneca and Metrion Biosciences.

Clathrodin, hymenidin and oroidin, and their synthetic analogues as inhibitors of the voltage-gated potassium channels.

We have prepared three alkaloids from the Agelas sponges, clathrodin, hymenidin and oroidin, and a series of their synthetic analogues, and evaluated their inhibitory effect against six isoforms of the Kv1 subfamily of voltage-gated potassium channels, Kv1.1-Kv1.6, expressed in Chinese Hamster ovary (CHO) cells using automated patch clamp electrophysiology assay. The most potent inhibitor was the (E)-N-(3-(2-amino-1H-imidazol-4-yl)allyl)-4,5-dichloro-1H-pyrrole-2-carboxamide (6g) with IC50 values between 1.4 and 6.1 µM against Kv1.3, Kv1.4, Kv1.5 and Kv1.6 channels. All compounds tested displayed selectivity against Kv1.1 and Kv1.2 channels. For confirmation of their activity and selectivity, compounds were additionally evaluated in the second independent system against Kv1.1-Kv1.6 and Kv10.1 channels expressed in Xenopus laevis oocytes under voltage clamp conditions where IC50 values against Kv1.3-Kv1.6 channels for the most active analogues (e.g. 6g) were lower than 1 µM. Because of the observed low sub-micromolar IC50 values and fairly low molecular weights, the prepared compounds represent good starting points for further optimisation towards more potent and selective voltage-gated potassium channel inhibitors.

Characterization of Endogenous Sodium Channels in the ND7-23 Neuroblastoma Cell Line: Implications for Use as a Heterologous Ion Channel Expression System Suitable for Automated Patch Clamp Screening.

The rodent neuroblastoma cell line, ND7-23, is used to express voltage-dependent sodium (Nav) and other neuronal ion channels resistant to heterologous expression in Chinese hamster ovary (CHO) or human embryonic kidney (HEK) cells. Their advantage is that they provide endogenous factors and signaling pathways to promote ion channel peptide folding, expression, and function at the cell surface and are also amenable to automated patch clamping. However, ND7-23 cells exhibit endogenous tetrodotoxin (TTX)-sensitive Nav currents, and molecular profiling has revealed the presence of Nav1.2, Nav1.3, Nav1.6, and Nav1.7 transcripts, but no study has determined which subtypes contribute to functional channels at the cell surface. We profiled the repertoire of functional Nav channels endogenously expressed in ND7-23 cells using the QPatch automated patch clamp platform and selective toxins and small molecules. The potency and subtype selectivity of the ligands (Icagen compound 68 from patent US-20060025415-A1-20060202, 4,9 anhydro TTX, and Protoxin-II) were established in human Nav1.3, Nav1.6, and Nav1.7 channel cell lines before application of selective concentrations to ND7-23 cells. Our data confirm previous studies that >97% of macroscopic Nav current in ND7-23 cells is carried by TTX-sensitive channels (300 nM TTX) and that Nav1.7 is the predominant channel contributing to this response (65% of peak inward current), followed by Nav1.6 (∼20%) and negligible Nav1.3 currents (∼2%). In addition, our data are the first to assess the Nav1.6 potency (50% inhibitory concentration [IC50] of 33 nM) and selectivity (50-fold over Nav1.7) of 4,9 anhydro TTX in human Nav channels expressed in mammalian cells, confirming previous studies of rodent Nav channels expressed in oocytes and HEK cells.