Analogs of α-conotoxin PnIC selectively inhibit α7ß2- over α7-only subtype nicotinic acetylcholine receptors via a novel allosteric mechanism.

This study was undertaken to identify and characterize the first ligands capable of selectively identifying nicotinic acetylcholine receptors containing α7 and ß2 subunits (α7ß2-nAChR subtype). Basal forebrain cholinergic neurons express α7ß2-nAChR. Here, they appear to mediate neuronal dysfunction induced by the elevated levels of oligomeric amyloid-ß associated with early Alzheimer's disease. Additional work indicates that α7ß2-nAChR are expressed across several further critically important cholinergic and GABAergic neuronal circuits within the central nervous system. Further studies, however, are significantly hindered by the inability of currently available ligands to distinguish heteromeric α7ß2-nAChR from the closely related and more widespread homomeric α7-only-nAChR subtype. Functional screening using two-electrode voltage-clamp electrophysiology identified a family of α7ß2-nAChR-selective analogs of α-conotoxin PnIC (α-CtxPnIC). A combined electrophysiology, functional kinetics, site-directed mutagenesis, and molecular dynamics approach was used to further characterize the α7ß2-nAChR selectivity and site of action of these α-CtxPnIC analogs. We determined that α7ß2-nAChR selectivity of α-CtxPnIC analogs arises from interactions at a site distinct from the orthosteric agonist-binding site shared between α7ß2- and α7-only-nAChR. As numerous previously identified α-Ctx ligands are competitive antagonists of orthosteric agonist-binding sites, this study profoundly expands the scope of use of α-Ctx ligands (which have already provided important nAChR research and translational breakthroughs). More immediately, analogs of α-CtxPnIC promise to enable, for the first time, both comprehensive mapping of the distribution of α7ß2-nAChR and detailed investigations of their physiological roles.

Factors affecting outcomes of second intent healing of nasal defects after Mohs micrographic surgery.

Reconstruction of nasal defects secondary to Mohs micrographic surgery (MMS) presents particular challenges related to the complex topography, skin quality, tissue laxity, and functional and aesthetic concerns of the region. Factors affecting outcomes resulting from second intent healing (SIH) on the nose have not been well described. The purpose of the study was to identify factors impacting outcomes of SIH for nasal tumors following MMS. Retrospective analysis was performed of all nasal lesions treated with MMS followed by SIH from a single surgical center over a 1.5-year period. Ninety-six cases were included. Chart review was performed, and data were collected including age, gender, nasal site, tumor type, defect size, depth, and number of MMS stages. Pre- and post-operative follow-up photographs were available for all cases. All five authors evaluated the photographs using the modified Manchester scar scale. Analysis was then conducted to identify features associated with good outcomes. Of the 96 tumors, 39 lesions (40.6%) were located on the nasal tip (including supratip), 32 (33.3%) on the ala/alar groove, 17 (17.7%) on the sidewall, and 8 (8.3%) on the dorsum. The average defect size was 0.83 cm2 (diameter of 1.06 cm ± 0.4). Defect diameter and defect depth were the factors that significantly impacted scar outcome (p < 0.001) in multivariate analysis. No significant functional deficits were reported. This retrospective study suggests that nasal defects with area less than 0.83 cm2 (or 1.06 cm diameter) and depth of defect not extending beyond the superficial fat healed well by SIH regardless of location on the nose.

Development of a proactive process to harmonize policy, infusion pump library, and electronic health record entries for continuous infusions at an academic medical center.

PURPOSE: Standardized processes to order and prepare medications can decrease the potential for error and provider uncertainty. Our health system utilizes a standard concentration policy, smart infusion pumps, and the electronic health record (EHR) to catalog, order, and deliver intravenous medications. A need for a more proactive and formalized process to ensure medication listings are harmonized between these 3 resources was identified. Standardizing these resources can reduce confusion, reduce time spent in pharmacy operations and nursing workflow, and may improve patient safety. The purpose of this quality improvement project was to compare and resolve inconsistencies between these 3 sources and to create a new process to assure uniformity in a complex work environment. SUMMARY: An audit-style comparison and evaluation of entries for continuous infusions within the standard concentration policy, the pump library, and the EHR was conducted. All continuous infusion entries within any one of these 3 sources were included. Key exclusion criteria included pediatric and neonatal infusions, intermittent infusions, and infusions in procedural areas. We compared the policy, the pump library, and the EHR to identify, document, and resolve discrepancies in medication name, concentration, rate, and volume; fluid restriction concentration; and upper and lower pump limits. A new method to ensure proactive continuity and consistent updates to the 3 sources was implemented into existing operational workflows. We recommended a total of 82 updates to policy (n = 48), the pump library (n = 30), and the EHR (n = 4) out of 187 continuous infusion entries. CONCLUSION: Standardizing infusion resources will reduce confusion, and improve pharmacy operations, nursing workflow, and patient safety.

Development and validation of an electronic health records-based opioid use disorder algorithm by expert clinical adjudication among patients with prescribed opioids.

BACKGROUND: In the US, over 200 lives are lost from opioid overdoses each day. Accurate and prompt diagnosis of opioid use disorders (OUD) may help prevent overdose deaths. However, international classification of disease (ICD) codes for OUD are known to underestimate prevalence, and their specificity and sensitivity are unknown. We developed and validated algorithms to identify OUD in electronic health records (EHR) and examined the validity of OUD ICD codes. METHODS: Through four iterations, we developed EHR-based OUD identification algorithms among patients who were prescribed opioids from 2014 to 2017. The algorithms and OUD ICD codes were validated against 169 independent "gold standard" EHR chart reviews conducted by an expert adjudication panel across four healthcare systems. After using 2014-2020 EHR for validating iteration 1, the experts were advised to use 2014-2017 EHR thereafter. RESULTS: Of the 169 EHR charts, 81 (48%) were reviewed by more than one expert and exhibited 85% expert agreement. The experts identified 54 OUD cases. The experts endorsed all 11 OUD criteria from the Diagnostic and Statistical Manual of Mental Disorders-5, including craving (72%), tolerance (65%), withdrawal (56%), and recurrent use in physically hazardous conditions (50%). The OUD ICD codes had 10% sensitivity and 99% specificity, underscoring large underestimation. In comparison our algorithm identified OUD with 23% sensitivity and 98% specificity. CONCLUSIONS AND RELEVANCE: This is the first study to estimate the validity of OUD ICD codes and develop validated EHR-based OUD identification algorithms. This work will inform future research on early intervention and prevention of OUD.

RgIA4 Prevention of Acute Oxaliplatin-Induced Cold Allodynia Requires α9-Containing Nicotinic Acetylcholine Receptors and CD3+ T-Cells.

Chemotherapy-induced neuropathic pain is a debilitating and dose-limiting side effect. Oxaliplatin is a third-generation platinum and antineoplastic compound that is commonly used to treat colorectal cancer and commonly yields neuropathic side effects. Available drugs such as duloxetine provide only modest benefits against oxaliplatin-induced neuropathy. A particularly disruptive symptom of oxaliplatin is painful cold sensitivity, known as cold allodynia. Previous studies of the Conus regius peptide, RgIA, and its analogs have demonstrated relief from oxaliplatin-induced cold allodynia, yielding improvement that persists even after treatment cessation. Moreover, underlying inflammatory and neuronal protection were shown at the cellular level in chronic constriction nerve injury models, consistent with disease-modifying effects. Despite these promising preclinical outcomes, the underlying molecular mechanism of action of RgIA4 remains an area of active investigation. This study aimed to determine the necessity of the α9 nAChR subunit and potential T-cell mechanisms in RgIA4 efficacy against acute oxaliplatin-induced cold allodynia. A single dose of oxaliplatin (10 mg/kg) was utilized followed by four daily doses of RgIA4. Subcutaneous administration of RgIA4 (40 µg/kg) prevented cold allodynia in wildtype mice but not in mice lacking the α9 nAChR-encoding gene, chrna9. RgIA4 also failed to reverse allodynia in mice depleted of CD3+ T-cells. In wildtype mice treated with oxaliplatin, quantitated circulating T-cells remained unaffected by RgIA4. Together, these results show that RgIA4 requires both chrna9 and CD3+ T-cells to exert its protective effects against acute cold-allodynia produced by oxaliplatin.

Consensus-Based Recommendations on the Prevention of Squamous Cell Carcinoma in Solid Organ Transplant Recipients: A Delphi Consensus Statement.

IMPORTANCE: There is a paucity of evidence to guide physicians regarding prevention strategies for cutaneous squamous cell carcinoma (CSCC) in solid organ transplant recipients (SOTRs). OBJECTIVE: To examine the development and results of a Delphi process initiated to identify consensus-based medical management recommendations for prevention of CSCC in SOTRs. EVIDENCE REVIEW: Dermatologists with more than 5 years' experience treating SOTRs were invited to participate. A novel actinic damage and skin cancer index (AD-SCI), consisting of 6 ordinal stages corresponding to an increasing burden of actinic damage and CSCC, was used to guide survey design. Three sequential web-based surveys were administered from January 1, 2019, to December 31, 2020. Pursuant to Delphi principles, respondents thoroughly reviewed all peer responses between rounds. Supplemental questions were also asked to better understand panelists' rationale for their responses. FINDINGS: The Delphi panel comprised 48 dermatologists. Respondents represented 13 countries, with 27 (56%) from the US. Twenty-nine respondents (60%) were Mohs surgeons. Consensus was reached with 80% or higher concordance among respondents when presented with a statement, question, or management strategy pertaining to prevention of CSCC in SOTRs. A near-consensus category of 70% to less than 80% concordance was also defined. The AD-SCI stage-based recommendations were established if consensus or near-consensus was achieved. The panel was able to make recommendations for 5 of 6 AD-SCI stages. Key recommendations include the following: cryotherapy for scattered actinic keratosis (AK); field therapy for AK when grouped in 1 anatomical area, unless AKs are thick in which case field therapy and cryotherapy were recommended; combination lesion directed and field therapy with fluorouracil for field cancerized skin; and initiation of acitretin therapy and discussion of immunosuppression reduction or modification for patients who develop multiple skin cancers at a high rate (10 CSCCs per year) or develop high-risk CSCC (defined by a tumor with approximately ≥20% risk of nodal metastasis). No consensus recommendation was achieved for SOTRs with a first low risk CSCC. CONCLUSIONS AND RELEVANCE: Physicians may consider implementation of panel recommendations for prevention of CSCC in SOTRs while awaiting high-level-of-evidence data. Additional clinical trials are needed in areas where consensus was not reached.

The Tunicate Metabolite 2-(3,5-Diiodo-4-methoxyphenyl)ethan-1-amine Targets Ion Channels of Vertebrate Sensory Neurons.

Marine tunicates produce defensive amino-acid-derived metabolites, including 2-(3,5-diiodo-4-methoxyphenyl)ethan-1-amine (DIMTA), but their mechanisms of action are rarely known. Using an assay-guided approach, we found that out of the many different sensory cells in the mouse dorsal root ganglion (DRG), DIMTA selectively affected low-threshold cold thermosensors. Whole-cell electrophysiology experiments using DRG cells, channels expressed in Xenopus oocytes, and human cell lines revealed that DIMTA blocks several potassium channels, reducing the magnitude of the afterhyperpolarization and increasing the baseline intracellular calcium concentration [Ca2+]i of low-threshold cold thermosensors. When injected into mice, DIMTA increased the threshold of cold sensation by >3 °C. DIMTA may thus serve as a lead in the further design of compounds that inhibit problems in the cold-sensory system, such as cold allodynia and other neuropathic pain conditions.

Discovery of Methylene Thioacetal-Incorporated α-RgIA Analogues as Potent and Stable Antagonists of the Human α9α10 Nicotinic Acetylcholine Receptor for the Treatment of Neuropathic Pain.

α9-Containing nicotinic acetylcholine receptors (nAChRs) are key targets for the treatment of neuropathic pain. α-Conotoxin RgIA4 is a peptide antagonist of human α9α10 nAChRs with high selectivity. However, structural rearrangement reveals a potential liability for clinical applications. We herein report our designer RgIA analogues stabilized by methylene thioacetal as nonopioid analgesic agents. We demonstrate that replacing disulfide loop I [CysI-CysIII] with methylene thioacetal in the RgIA skeleton results in activity loss, whereas substitution of loop II [CysII-CysIV] can be accommodated. The lead molecule, RgIA-5524, exhibits highly selective inhibition of α9α10 nAChRs with an IC50 of 0.9 nM and much reduced degradation in human serum. In vivo studies showed that RgIA-5524 relieves chemotherapy-induced neuropathic pain in wild type but not α9 knockout mouse models, demonstrating that α9-containing nAChRs are necessary for the therapeutic effects. This work highlights the application of methylene thioacetal as a disulfide surrogate in conotoxin-based, disulfide-rich peptide drugs.

Selective Penicillamine Substitution Enables Development of a Potent Analgesic Peptide that Acts through a Non-Opioid-Based Mechanism.

Venom-derived compounds are of broad interest in neuropharmacology and drug development. α-Conotoxins are small disulfide-containing peptides from Conus snails that target nicotinic acetylcholine receptors (nAChRs) and are in clinical development for non-opioid-based treatment of intractable pain. Although refined by evolution for interaction with target prey receptors, enhancements of pharmacological properties are needed for use in mammalian systems. Therefore, we synthesized analogues of α-conotoxin RgIA using a combination of selective penicillamine substitutions together with natural and non-natural amino acid replacements. This approach resulted in a peptide with 9000-fold increased potency on the human α9α10 nAChR and improved resistance to disulfide shuffling compared to the native peptide. The lead analogue, RgIA-5474, potently blocked α9α10 nAChRs, but not opioid- or other pain-related targets. In addition, RgIA-5474 effectively reversed chemotherapy-induced neuropathic pain.

A Histopathologic Scoring System for Perineural Invasion Correlates With Adverse Outcomes in Patients With Cutaneous Squamous Cell Carcinoma.

BACKGROUND: Perineural invasion (PNI) is a known risk factor for recurrence, metastasis, and death in cutaneous squamous cell carcinoma (cSCC). Current staging systems include PNI, but none define its extent or severity. OBJECTIVE: To identify histopathologic features of cSCC with PNI that may be associated with adverse outcomes. MATERIALS AND METHODS: This is a retrospective cohort study that included 45 patients with cSCC and PNI treated with surgical excision. Histopathologic slides were analyzed for 5 features of PNI: largest affected nerve diameter, number of nerves affected, depth of nerve involvement, intra- versus extratumoral PNI, and focal versus circumferential PNI. RESULTS: The median largest affected nerve diameter was 0.13 mm, and the median number of nerve structures involved was 4. After a median follow-up time of 24 months, 6 patients developed adverse outcomes, including 2 local recurrences, 4 metastases, and 2 tumor-related deaths. Univariate logistic regression analysis revealed that nerve diameter and number of affected nerves were significantly associated with adverse outcome. A composite PNI score, calculated from 5 histopathologic features, was the strongest predictor of adverse outcome (p = .020). CONCLUSION: Histopathologic features of PNI can be quantified with a composite PNI score that is significantly associated with adverse outcomes in cSCC.

Dermatofibrosarcoma protuberans in pregnancy: a case series and review of the literature.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous sarcoma, which has been reported in pregnancy. This case series reports the clinical and histopathological findings of DFSP in pregnancy. METHODS: Eighteen cases of DFSP, including six unreported cases and 12 cases from the literature, were identified. Age, anatomic location, tumor size, changes in tumor characteristics during pregnancy, histopathological features, and treatment were recorded. Follow-up data, when available, were noted. RESULTS: The average age of the cohort was 30.6 years (range 19-38). Ten tumors (55.6%) were located on the trunk, four (22.2%) on the head and neck, three (16.7%) on the extremities, and one (5.6%) in the genitalia. Most tumors demonstrated features of conventional DFSP (12/18, 66.7%), while the remaining were identified as DFSP with fibrosarcomatous (FS) change (3/18, 16.7%), atrophic DFSP (2/18, 11.1%), and myxoid DFSP (1/18, 5.6%). Treatment was reported in 17 cases, at least nine of which were treated postpartum. Ten patients were treated with excision, while seven underwent Mohs micrographic surgery. Three patients recurred on follow-up, one with local recurrence and two with distant metastasis. CONCLUSIONS: DFSP can undergo enlargement or change in size or color in pregnancy, possibly mediated by hormones. While the majority of cases in this series represented conventional DFSP, unusual clinical and histopathological variants were also present. Treatment in most cases can be safely delayed until after delivery, but recurrent or very large tumors may require treatment prepartum. Close monitoring for recurrence or metastasis is advised.

Association of Treatment Facility Characteristics With Overall Survival After Mohs Micrographic Surgery for T1a-T2a Invasive Melanoma.

Importance: Early-stage melanoma, among the most common cancers in the US, is typically treated with wide local excision. However, recent advances in immunohistochemistry have led to an increasing number of these cases being excised via Mohs micrographic surgery (MMS). Although studies of resections for other cancers have reported that facility-level factors are associated with patient outcomes, it is not yet established how these factors may affect outcomes for patients treated with Mohs micrographic surgery. Objective: To evaluate the association of treatment center academic affiliation and case volume with long-term patient survival after MMS for T1a-T2a invasive melanoma. Design, Setting, and Participants: In a retrospective cohort study, 4062 adults with nonmetastatic, T1a-T2a melanoma diagnosed from 2004 to 2014 and treated with MMS in the National Cancer Database (NCDB) were identified. The NCDB includes all reportable cases from Commission on Cancer-accredited facilities and is estimated to capture approximately 50% of all incident melanomas in the US. Multivariable survival analyses were conducted using Cox proportional hazards models. Data analysis was conducted from February 27 to August 18, 2020. Exposures: Treatment facility characteristics. Main Outcomes and Measures: Overall survival. Results: The study population included 4062 patients (2213 [54.5%] men; median [SD] age, 60 [16.3] years) treated at 462 centers. Sixty-two centers were top decile-volume facilities (TDVFs), which treated 1757 patients (61.9%). Most TDVFs were academic institutions (37 of 62 [59.7%]). On multivariable analysis, treatment at an academic center was associated with a nearly 30% reduction in hazard of death (hazard ratio, 0.730; 95% CI, 0.596-0.895). In a separate analysis, treatment at TDVFs was also associated with improved survival (hazard ratio, 0.795; 95% CI, 0.648-0.977). Conclusions and Relevance: In this cohort study, treatment of patients with T1a-T2a invasive melanoma excised with MMS at academic and top decile-volume (≥8 cases per year) facilities was associated with improved long-term survival compared with those excised by MMS at nonacademic and low-volume facilities. Identification and protocolization of the practices of these facilities may help to reduce survival differences between centers.