Computer Simulation of Three-Phase Equilibria for Some Water/n-Alkane Binary Systems.

In this work, the vapor-liquid-liquid equilibrium (VLLE) of the water/n-pentane, water/n-hexane, water/n-octane, and water/n-decane binary systems is calculated by computer simulation using the NVT-Gibbs ensemble (in the version of three simulation boxes) combined with the configurational bias Monte Carlo method. The combination of both methods, the molecular potential models used, and the simulation details allowed us to calculate the triphasic equilibrium properties of the systems studied: the densities of the three phases in equilibrium, their compositions, and potential energies. In previous works, these simulations were not carried out at a temperature range nor water/n-alkanes systems simulated in this work, probably because they are highly nonideal systems; so, to the best of our knowledge, this is the first time that this phenomenon is studied in detail. The results from VLLE simulations of the water/n-pentane system for temperatures from 343.2 to 435 K, the water/n-hexane system for temperatures from 373.11 to 473.15 K, the water/n-octane system for temperatures from 310.9 to 500 K, and for the water/n-decane system for temperatures from 374.15 to 525 K are reported here. The temperature range was selected in concordance with the experimental data available for an adequate study of the VLLE simulation results. The subcritical densities (vapor and liquid rich in n-alkane phases) at various temperatures fit well with the scaling law and the law of rectilinear diameters, allowing the estimation of upper critical end point temperature and density of the VLLE. The simulation results show a good prediction with experimental data reports in the literature.

Antineoplastic effect of compounds C14 and P8 on TNBC and radioresistant TNBC cells by stabilizing the K-Ras4BG13D/PDE6δ complex.

Introduction: Breast cancer (BC) is the leading cause of cancer-related deaths among women, with triple-negative breast cancer (TNBC) representing one of the most aggressive and treatment-resistant subtypes. In this study, we aimed to evaluate the antitumor potential of C14 and P8 molecules in both TNBC and radioresistant TNBC cells. These compounds were chosen for their ability to stabilize the complex formed by the overactivated form of K-Ras4BG13D and its membrane transporter (PDE6δ). Methods: The antitumor potential of C14 and P8 was assessed using TNBC cell lines, MDA-MB-231, and the radioresistant derivative MDA-MB-231RR, both carrying the K-Ras4B> G13D mutation. We investigated the compounds' effects on K-Ras signaling pathways, cell viability, and tumor growth in vivo. Results: Western blotting analysis determined the negative impact of C14 and P8 on the activation of mutant K-Ras signaling pathways in MDA-MB-231 and MDA-MB-231RR cells. Proliferation assays demonstrated their efficacy as cytotoxic agents against K-RasG13D mutant cancer cells and in inducing apoptosis. Clonogenic assays proven their ability to inhibit TNBC and radioresistant TNBC cell clonogenicity. In In vivo studies, C14 and P8 inhibited tumor growth and reduced proliferation, angiogenesis, and cell cycle progression markers. Discussion: These findings suggest that C14 and P8 could serve as promising adjuvant treatments for TNBC, particularly for non-responders to standard therapies. By targeting overactivated K-Ras and its membrane transporter, these compounds offer potential therapeutic benefits against TNBC, including its radioresistant form. Further research and clinical trials are warranted to validate their efficacy and safety as novel TNBC treatments.

The United States dermatology inpatient workforce between 2013 and 2019: a Medicare analysis reveals contraction of the workforce and vast access deserts-a cross-sectional analysis.

While time spent practicing inpatient dermatology has decreased since the 1990s, less is known about the current state of inpatient dermatology. We describe the distribution and frequency of inpatient dermatology encounters servicing the United States Medicare population between 2013 and 2019. Cross-sectional analysis of publicly available inpatient Medicare Part B claims data from 2013 to 2019 was conducted. Main outcomes and measures were characteristics and trends of dermatologists performing inpatient encounters. Categorical variables were compared using χ2 analysis. Trends were analyzed for linearity using Pearson correlation coefficient. 782 physicians met inclusion criteria for inclusion. Dermatologists were more often male (56.5%), possessing allopathic Medical Doctorate (MD) (86.3%), and in metropolitan settings (98.2%). However, proportion of female inpatient dermatologists increased significantly (37.9% to 46.2%). Across rural and metropolitan practices, number of inpatient physicians (2013: 356; 2019: 281) and number of medical centers in which dermatology encounters occurred (2013: 239; 2019: 157) decreased, more significantly in non-residency-associated institutions. Spatial analysis revealed wide regions lacking dermatologists meeting defined criteria. Limitations included the need for ten Medicare inpatient encounters for inclusion, counties without reported data. In conclusion, the number of dermatologists performing > 10 inpatient encounters per year is decreasing, and large variations exist in the number of U.S. inpatient dermatology visits.

KCNQ1 p.D446E Variant as a Risk Allele for Arrhythmogenic Phenotypes: Electrophysiological Characterization Reveals a Complex Phenotype Affecting the Slow Delayed Rectifier Potassium Current (IKs) Voltage Dependence by Causing a Hyperpolarizing Shift and a Lack of Response to Protein Kinase A Activation.

Genetic testing is crucial in inherited arrhythmogenic channelopathies; however, the clinical interpretation of genetic variants remains challenging. Incomplete penetrance, oligogenic, polygenic or multifactorial forms of channelopathies further complicate variant interpretation. We identified the KCNQ1/p.D446E variant in 2/63 patients with long QT syndrome, 30-fold more frequent than in public databases. We thus characterized the biophysical phenotypes of wildtype and mutant IKs co-expressing these alleles with the ß-subunit minK in HEK293 cells. KCNQ1 p.446E homozygosity significantly shifted IKs voltage dependence to hyperpolarizing potentials in basal conditions (gain of function) but failed to shift voltage dependence to hyperpolarizing potentials (loss of function) in the presence of 8Br-cAMP, a protein kinase A activator. Basal IKs activation kinetics did not differ among genotypes, but in response to 8Br-cAMP, IKs 446 E/E (homozygous) activation kinetics were slower at the most positive potentials. Protein modeling predicted a slower transition of the 446E Kv7.1 tetrameric channel to the stabilized open state. In conclusion, biophysical and modelling evidence shows that the KCNQ1 p.D446E variant has complex functional consequences including both gain and loss of function, suggesting a contribution to the pathogenesis of arrhythmogenic phenotypes as a functional risk allele.

Updates in SJS/TEN: collaboration, innovation, and community.

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) is a predominantly drug-induced disease, with a mortality rate of 15-20%, that engages the expertise of multiple disciplines: dermatology, allergy, immunology, clinical pharmacology, burn surgery, ophthalmology, urogynecology, and psychiatry. SJS/TEN has an incidence of 1-5/million persons per year in the United States, with even higher rates globally. One of the challenges of SJS/TEN has been developing the research infrastructure and coordination to answer questions capable of transforming clinical care and leading to improved patient outcomes. SJS/TEN 2021, the third research meeting of its kind, was held as a virtual meeting on August 28-29, 2021. The meeting brought together 428 international scientists, in addition to a community of 140 SJS/TEN survivors and family members. The goal of the meeting was to brainstorm strategies to support the continued growth of an international SJS/TEN research network, bridging science and the community. The community workshop section of the meeting focused on eight primary themes: mental health, eye care, SJS/TEN in children, non-drug induced SJS/TEN, long-term health complications, new advances in mechanisms and basic science, managing long-term scarring, considerations for skin of color, and COVID-19 vaccines. The meeting featured several important updates and identified areas of unmet research and clinical need that will be highlighted in this white paper.

Multicentre, prospective, randomized control non-inferiority trial of bladder catheter management in colon surgery.

AIM: Perioperative bladder catheterization is a controversial issue. Most current recommendations are based on data from open surgery extrapolated to enhanced recovery after surgery or fast-track programmes ranging between 24 and 48 h. The aim of this study is to provide a rationale for reducing catheterization time while at the same time avoiding acute urine retention (AUR), in patients undergoing scheduled laparoscopic colon surgery. METHOD: This is a multicentre, prospective, controlled, randomized non-inferiority study of bladder catheter management in patients undergoing scheduled laparoscopic colon surgery, randomized into two groups: experimental (with catheter removal immediately after surgery) and control (with catheter removal 24 h post-surgery). The main outcome will be the development of AUR, and secondary outcomes the development of urinary infection within the first 30 days and hospital stay. Demographic, surgical and pathological variables will also be evaluated, especially the development of adverse effects assessed according to the Clavien scale and the Comprehensive Complication Index. Following the literature, we assume an incidence of AUR of 11% and a margin of non-inferiority (delta) of 8% and estimate that a sample size of 208 patients per group will be required (with an estimated 10% of losses per group). CONCLUSIONS: In this study we try to demonstrate that the bladder catheter can be removed immediately after scheduled laparoscopic colon surgery, without increasing acute urine retention. This measure would offers the benefits of earlier mobilization and reduces catheter-related morbidity.

Synergistic effect of antagonists to KRas4B/PDE6 molecular complex in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis among all human cancers as it is highly resistant to chemotherapy. K-Ras mutations usually trigger the development and progression of PDAC. We hypothesized that compounds stabilizing the KRas4B/PDE6δ complex could serve as PDAC treatments. Using in silico approaches, we identified the small molecules C14 and P8 that reduced K-Ras activation in primary PDAC cells. Importantly, C14 and P8 significantly prevented tumor growth in patient-derived xenotransplants. Combined treatment with C14 and P8 strongly increased cytotoxicity in PDAC cell lines and primary cultures and showed strong synergistic antineoplastic effects in preclinical murine PDAC models that were superior to conventional therapeutics without causing side effects. Mechanistically, C14 and P8 reduced tumor growth by inhibiting AKT and ERK signaling downstream of K-RAS leading to apoptosis, specifically in PDAC cells. Thus, combined treatment with C14 and P8 may be a superior pharmaceutical strategy to improve the outcome of PDAC.

Implementation and evaluation of a store-and-forward teledermatology workflow in a United States safety-net hospital urgent care emergency center: A retrospective cohort study.

Background: Teledermatology (TD) is an important method for increasing access to care in outpatient settings. However, less is known regarding its use in emergency/urgent care centers. Objective: To evaluate the effect of TD on urgent care emergency center (UCEC) dwell time and postencounter utilization. Study type and methods: This retrospective cohort study evaluated patients in a safety-net hospital (Parkland Health, Dallas, Texas, USA) UCEC, who (1) received a TD consult in 2018, (2) were referred to dermatology clinic in 2017, or (3) were referred to dermatology clinic in 2018 without a TD consult. Results: We evaluated 2024 patients from 2017 to 2018. Of the 973 referred to dermatology clinic in 2018, 332 (34%) received TD consultations. Mean dwell time for patients receiving TD was longer versus the 2017 cohort (303 vs 204 minutes, respectively). Patients receiving TD consultation with inflammatory skin conditions had lower odds of dermatology clinic visits compared with those that did not (odds ratio, 0.5; 95% CI, 0.3-0.8). Teledermatology was not associated with differences in repeat UCEC utilization. Limitations: Single institution study and inability to account for differences in patient complexity. Conclusion: TD increases dwell time in a safety-net hospital's UCEC but can reduce dermatology clinic utilization for patients with inflammatory skin conditions.

A plague passing over: Clinical features of the 2022 mpox outbreak in patients of color living with HIV.

INTRODUCTION: Compared with previous geographically localized outbreaks of monkeypox (MPOX), the scale of the 2022 global mpox outbreak has been unprecedented, yet the clinical features of this outbreak remain incompletely characterized. METHODS: We identified patients diagnosed with mpox by polymerase chain reaction (PCR; n = 36) from July to September 2022 at a single, tertiary care institution in the USA. Demographics, clinical presentation, infection course, and histopathologic features were reviewed. RESULTS AND CONCLUSION: Men who have sex with men (89%) and people living with HIV (97%) were disproportionately affected. While fever and chills (56%) were common, some patients (23%) denied any prodromal symptoms. Skin lesions showed a wide range of morphologies, including papules and pustules, and lesions showed localized, not generalized, spread. Erythema was also less appreciable in skin of colour patients (74%). Atypical clinical features and intercurrent skin diseases masked the clinical recognition of several cases, which were ultimately diagnosed by PCR. Biopsies showed viral cytopathic changes consistent with Orthopoxvirus infections. All patients in this case series recovered without complications, although six patients (17%) with severe symptoms were treated with tecovirimat without complication.

Development of a Skin-Directed Scoring System for Stevens-Johnson Syndrome and Epidermal Necrolysis: A Delphi Consensus Exercise.

Importance: Scoring systems for Stevens-Johnson syndrome and epidermal necrolysis (EN) only estimate patient prognosis and are weighted toward comorbidities and systemic features; morphologic terminology for EN lesions is inconsistent. Objectives: To establish consensus among expert dermatologists on EN terminology, morphologic progression, and most-affected sites, and to build a framework for developing a skin-directed scoring system for EN. Evidence Review: A Delphi consensus using the RAND/UCLA appropriateness criteria was initiated with a core group from the Society of Dermatology Hospitalists to establish agreement on the optimal design for an EN cutaneous scoring instrument, terminology, morphologic traits, and sites of involvement. Findings: In round 1, the 54 participating dermatology hospitalists reached consensus on all 49 statements (30 appropriate, 3 inappropriate, 16 uncertain). In round 2, they agreed on another 15 statements (8 appropriate, 7 uncertain). There was consistent agreement on the need for a skin-specific instrument; on the most-often affected skin sites (head and neck, chest, upper back, ocular mucosa, oral mucosa); and that blanching erythema, dusky erythema, targetoid erythema, vesicles/bullae, desquamation, and erosions comprise the morphologic traits of EN and can be consistently differentiated. Conclusions and Relevance: This consensus exercise confirmed the need for an EN skin-directed scoring system, nomenclature, and differentiation of specific morphologic traits, and identified the sites most affected. It also established a baseline consensus for a standardized EN instrument with consistent terminology.

Cutaneous Angiosarcoma.

This case report describes a large, purpuric plaque involving most of the right face with associated periorbital swelling but without ulceration.

Severe Mpox Infections in People With Uncontrolled Human Immunodeficiency Virus.

In the current mpox outbreak, infections are usually self-limited. We describe 3 patients with uncontrolled HIV and mpox infections lasting months, causing debilitating lesions, complications, and death, despite initiating anti-mpox and antiretroviral therapy. Delayed treatment of mpox with antiviral agents may contribute to poor outcomes in severely immunocompromised patients.

Sudden Conjunctivitis, Lymphopenia, and Rash Combined With Hemodynamic Changes (SCoRCH) After Trimethoprim-Sulfamethoxazole Use: A Case Series Study of a Hypersensitivity Reaction.

Importance: Trimethoprim-sulfamethoxazole (TMP-SMX) hypersensitivity reaction, ranging from circulatory shock to aseptic meningitis and respiratory failure, is a potentially life-threatening condition with dermatologic relevance. Objective: To describe the mucocutaneous findings and clinical features of TMP-SMX hypersensitivity reaction. Design, Setting, and Participants: This was a retrospective case series study of 7 patients who developed a characteristic rash, hemodynamic changes, and end-organ dysfunction after treatment with TMP-SMX at a large university hospital system during January 2013 to March 2022. Exposures: Treatment with TMP-SMX within 2 weeks of the reaction. Main Outcome and Measures: Descriptions of the condition, including the demographic information of the affected population, the reaction timeline, and mucocutaneous and clinical features. Results: The cohort comprised 7 patients (median [range] age, 20 [15-66] years; 4 female and 3 male). The most common mucocutaneous findings were generalized sunburn-like erythema without scale, conjunctivitis, and mild facial and acral edema. Three patients had previous exposure to TMP-SMX and developed symptoms in 1 day or less, while those without prior exposure presented from 4 to 11 days after drug initiation. Among the 7 patients, 6 had fever, 7 had hypotension, and 7 had tachycardia. All patients had lymphopenia and evidence of end-organ dysfunction with either kidney or liver involvement. Median (range) time to resolution was 72 (48-96) hours. Conclusions and Relevance: This retrospective case series indicates that SCoRCH (sudden conjunctivitis, lymphopenia, and rash combined with hemodynamic changes) should be considered in the differential diagnosis of patients presenting with acute generalized sunburn-like erythema, conjunctivitis, systemic symptoms, and hemodynamic changes in the setting of recent TMP-SMX use.

Efficacy of a lay community health worker (promotoras de salud) program to improve adherence to emollients in Spanish-speaking Latin American pediatric patients in the United States with atopic dermatitis: A randomized, controlled, evaluator-blinded study.

BACKGROUND: Latin American patients in the United States experience significant health disparities. Community health workers (promotoras de salud) reduce disparities by providing culturally appropriate education. While educational interventions have been studied in atopic dermatitis (AD), a chronic dermatologic condition affecting children, none have evaluated the use of promotoras in Spanish-speaking pediatric patients in the United States. OBJECTIVE: To create and evaluate a promotora-led education program for Spanish-speaking caregivers of Latin American, pediatric patients with AD through a randomized, controlled, evaluator-blinded study. METHODS: Children with moderate/severe AD (n = 48) were recruited from the pediatric dermatology clinic at Children's Health℠ in Dallas, TX and randomized to receive clinic education (n = 26) or clinic education plus promotora home visits (n = 22). The primary outcome was overall adherence to topical emollients over the 12-week study, quantified by MEMSCap™ devices; several secondary endpoints were evaluated. RESULTS: Intention-to-treat analysis revealed a trend toward increased overall adherence to emollients over the 12-week study period in promotora (median [interquartile range, IQR]: 43% [26%-61%]) versus non-promotora (median [IQR]: 20% [11%-49%]) (p = .09) groups. SCORAD, AD knowledge, and Spanish-language Parental Quality of Life Questionnaire for AD (Sp-PIQoL-AD) improved in both groups, although there was no statistically significant difference between groups. There was a trend toward increased AD knowledge at Week 4 (p = .06) in the promotora group. CONCLUSIONS: A promotora-led educational intervention is a promising approach in increasing caregiver medication adherence in pediatric, Latin American patients with AD in the United States. Further research using creative and culturally appropriate strategies to increase medication adherence is necessary to reduce health disparities in other racial and ethnic minority populations in the United States.