The effect of chemical constitution on polyisoprene dynamics.

Polyisoprene (PI) melts have been studied, with most reports focusing on systems with high 1,4-cis content. In contrast, 1,4-trans PI homopolymers or random copolymers have seldom been examined, despite a handful of investigations suggesting a distinct dynamic behavior. Herein, we employ all-atom simulations to investigate the effect of chemical architecture on the dynamics of cis and trans-PI homopolymers, as well as copolymers. We examine the thermodynamic, conformational, and structural properties of the polymers and validate the performance of the models. We probe chain dynamics, revealing that cis-PI presents accelerated translation and reorientation modes relative to trans as recorded by the mean square displacement of the chain center-of-mass as well as by the characteristic times of the lower modes in a Rouse analysis. Interestingly, progressing to higher modes, we observe a reversal with trans units exhibiting faster dynamics. This was further confirmed by calculations of local carbon-hydrogen vector reorientation dynamics, which offer a microscopic view of segmental mobility. To obtain insight into the simulation trajectories, we evaluate the intermediate incoherent scattering function that supports a temperature-dependent crossover in relative mobility that extends over separations beyond the Kuhn-length level. Finally, we analyzed the role of non-Gaussian displacements, which demonstrate that cis-PI exhibits increased heterogeneity in dynamics over short-timescales in contrast to trans-PI, where deviations persist over times extending to terminal dynamics. Our all-atom simulations provide a fundamental understanding of PI dynamics and the impact of microstructure while providing important data for the design and optimization of PI-based materials.

The dangers of human papillomavirus (HPV) laser plume and best safety practices.

Human papillomavirus (HPV) remains to be one of the most common viruses that afflicts the skin and mucosa. Direct contact with cutaneous lesions facilitates a majority of viral transmission. However, the development of laser therapy as treatment for HPV brought to attention the concern of infectious laser plume and the risk it poses to those inhaling it. We conducted a literature review using English articles in PubMed to validate this risk and propose the best safety practices dermatologists can apply when using laser therapy as treatment for HPV. Our investigation identified smoke evacuators as primary modes of mitigation, and we suggest further studies will aid in the refinement of best practice recommendations.

The risk of metastases from squamous cell carcinoma of the skin.

Cutaneous squamous cell carcinoma (cSCC) is the second most common nonmelanoma skin cancer, accounting for 20% of all skin cancers. The risk of the disease continues to rise annually with an estimated 50-200% increase in incidence within the last three decades. Although cSCC is one of the most common skin cancers, reported having 1 million cases per year in the United States, there is inconsistency with its reported metastatic rate. Research exploring cSCC metastasis found an overall rate of 1.2-5% but this range varies, and some dermatologists are finding cSCC's ability to spread more worrisome. This allows for clinical variation in the appropriate treatments and follow-up guidelines when diagnosing a patient with cSCC. Poor prognosis in patients with a high metastatic potential makes cSCC clinically problematic. Clinician emphasis should be put on risk factors, anatomical site, tumor presentation, and histological features when evaluating cSCC's metastatic potential. In this review, specific skin conditions that predispose to cSCC and discrepancies in its reported metastatic potential will be discussed.

Bacteriophages: An Alternative to Combat Antibiotic Resistance?

BACKGROUND: Antibiotic resistance has become one of the largest pitfalls of modern medicine, and this has fueled the search for a safe and effective alternative. Of these alternatives, bacteriophage (phage) therapy has emerged as a potential option since it is capable of destroying pathogenic bacteria, without disrupting commensal bacterial populations. Although numerous studies have shown its efficacy in various conditions such as dysentery, sepsis, and meningitis, very little research has focused on its prospective usage to treat dermatological conditions. This review discusses the emerging phage therapy studies surrounding infections caused by Cutibacterium acnes (C. acnes), Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), and Klebsiella pneumoniae (K. pneumoniae). Phage therapy shows major potential for future usage in the field of dermatology, yet further research must be performed to assure safety and efficacy in humans. J Drugs Dermatol. 2022;21(12):1311-1315. doi:10.36849/JDD.6638.

Bleach baths for atopic dermatitis: A systematic review and meta-analysis including unpublished data, Bayesian interpretation, and GRADE.

BACKGROUND: Bleach bathing is frequently recommended to treat atopic dermatitis (AD), but its efficacy and safety are uncertain. OBJECTIVE: To systematically synthesize randomized controlled trials (RCTs) addressing bleach baths for AD. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and GREAT from inception to December 29, 2021, for RCTs assigning patients with AD to bleach vs no bleach baths. Paired reviewers independently and in duplicate screened records, extracted data, and assessed risk of bias (Cochrane version 2) and GRADE quality of evidence. We obtained unpublished data, harmonized individual patient data and did Frequentist and Bayesian random-effects meta-analyses. RESULTS: There were 10 RCTs that enrolled 307 participants (median of mean age 7.2 years, Eczema Area Severity Index baseline mean of means 27.57 [median SD, 10.74]) for a median of 6 weeks (range, 4-10). We confirmed that other trials registered globally were terminated. Bleach baths probably improve AD severity (22% vs 32% improved Eczema Area Severity Index by 50% [ratio of means 0.78, 95% credible interval 0.59-0.99]; moderate certainty) and may slightly reduce skin Staphylococcal aureus colonization (risk ratio, 0.89 [95% confidence interval, 0.73-1.09]; low certainty). Adverse events, mostly dry skin and irritation, along with itch, patient-reported disease severity, sleep quality, quality of life, and risk of AD flares were not clearly different between groups and of low to very low certainty. CONCLUSION: In patients with moderate-to-severe AD, bleach baths probably improve clinician-reported severity by a relative 22%. One in 10 will likely improve severity by 50%. Changes in other patient-important outcomes are uncertain. These findings support optimal eczema care and the need for additional large clinical trials. TRIAL REGISTRATION: PROSPERO Identifier: CRD42021238486.

Coupling between Polymer Conformations and Dynamics Near Amorphous Silica Surfaces: A Direct Insight from Atomistic Simulations.

The dynamics of polymer chains in the polymer/solid interphase region have been a point of debate in recent years. Its understanding is the first step towards the description and the prediction of the properties of a wide family of commercially used polymeric-based nanostructured materials. Here, we present a detailed investigation of the conformational and dynamical features of unentangled and mildly entangled cis-1,4-polybutadiene melts in the vicinity of amorphous silica surface via atomistic simulations. Accounting for the roughness of the surface, we analyze the properties of the polymer chains as a function of their distance from the silica slab, their conformations and the chain molecular weight. Unlike the case of perfectly flat and homogeneous surfaces, the monomeric translational motion parallel to the surface was affected by the presence of the silica slab up to distances comparable with the extension of the density fluctuations. In addition, the intramolecular dynamical heterogeneities in adsorbed chains were revealed by linking the conformations and the structure of the adsorbed chains with their dynamical properties. Strong dynamical heterogeneities within the adsorbed layer are found, with the chains possessing longer sequences of adsorbed segments ("trains") exhibiting slower dynamics than the adsorbed chains with short ones. Our results suggest that, apart from the density-dynamics correlation, the configurational entropy plays an important role in the dynamical response of the polymers confined between the silica slabs.

Consensus Statement for the Management and Treatment of Sturge-Weber Syndrome: Neurology, Neuroimaging, and Ophthalmology Recommendations.

BACKGROUND: Sturge-Weber syndrome (SWS) is a sporadic, neurocutaneous syndrome involving the skin, brain, and eyes. Because of the variability of the clinical manifestations and the lack of prospective studies, consensus recommendations for management and treatment of SWS have not been published. OBJECTIVE: This article consolidates the current literature with expert opinion to make recommendations to guide the neuroimaging evaluation and the management of the neurological and ophthalmologic features of SWS. METHODS: Thirteen national peer-recognized experts in neurology, radiology, and ophthalmology with experience treating patients with SWS were assembled. Key topics and questions were formulated for each group and included (1) risk stratification, (2) indications for referral, and (3) optimum treatment strategies. An extensive PubMed search was performed of English language articles published in 2008 to 2018, as well as recent studies identified by the expert panel. The panel made clinical practice recommendations. CONCLUSIONS: Children with a high-risk facial port-wine birthmark (PWB) should be referred to a pediatric neurologist and a pediatric ophthalmologist for baseline evaluation and periodic follow-up. In newborns and infants with a high-risk PWB and no history of seizures or neurological symptoms, routine screening for brain involvement is not recommended, but brain imaging can be performed in select cases. Routine follow-up neuroimaging is not recommended in children with SWS and stable neurocognitive symptoms. The treatment of ophthalmologic complications, such as glaucoma, differs based on the age and clinical presentation of the patient. These recommendations will help facilitate coordinated care for patients with SWS and may improve patient outcomes.

DMSO: an aid to combat pain and pruritus.

Dimethyl sulfoxide (DMSO) is a highly reactive by-product of paper production in the form of an odorless, colorless liquid that has been studied since the 1860s. Initially it was utilized as a solvent, but more recently it is being investigated for therapeutic applications. Owing to its versatility, the use of DMSO has been proposed in many different medical fields for a variety of applications, with possibly the widest use being in the field of dermatology. The clinical interest in the use of DMSO for dermatology conditions stems from this solution's efficacy as a vehicle to deliver pharmacological agents across the stratum corneum and its ability to penetrate biological membranes. Currently there is only one FDA approval for the use of DMSO, and it is not in the dermatologic field but rather for interstitial cystitis. Outside of the FDA scope of usage, DMSO is used frequently to treat osteoarthritis in humans and animals, as well as other chronic pain conditions. This suggests the possible utility of DMSO being applicable to other inflammatory conditions such as pruritus. Further research is necessary to explore the promising utilization opportunities of DMSO in dermatology.

Consensus Statement for the Management and Treatment of Port-Wine Birthmarks in Sturge-Weber Syndrome.

Importance: Sturge-Weber syndrome (SWS) is a neurocutaneous syndrome involving the skin, brain, and eyes. Consensus recommendations for management are lacking. Objective: To consolidate the current literature with expert opinion to make recommendations that will guide treatment and referral for patients with port-wine birthmarks (PWBs). Evidence Review: In this consensus statement, 12 nationally peer-recognized experts in dermatology with experience treating patients with SWS were assembled. Key topics and questions were formulated for each group and included risk stratification, optimum treatment strategies, and recommendations regarding light-based therapies. A systematic PubMed search was performed of English-language articles published between December 1, 2008, and December 1, 2018, as well as other pertinent studies identified by the expert panel. Clinical practice guidelines were recommended. Findings: Treatment of PWBs is indicated to minimize the psychosocial impact and diminish nodularity and potentially tissue hypertrophy. Better outcomes may be attained if treatments are started at an earlier age. In the US, pulsed dye laser is the standard for all PWBs regardless of the lesion size, location, or color. When performed by experienced physicians, laser treatment can be safe for patients of all ages. The choice of using general anesthesia in young patients is a complex decision that must be considered on a case-by-case basis. Conclusions and Relevance: These recommendations are intended to help guide clinical practice and decision-making for patients with SWS and those with isolated PWBs and may improve patient outcomes.

Lasers, Birthmarks, and Sturge-Weber Syndrome: A Pilot Survey.

BACKGROUND AND OBJECTIVES: There is limited or no data on the experience of patients with Sturge-Weber Syndrome (SWS) and/or their parents who seek out laser treatments for their port-wine birthmark (PWB). Our study aimed to develop a survey to understand patient perspectives on laser therapy and subsequent behaviors while focusing on three elements of the health belief model: perceived susceptibility, perceived benefits, and perceived barriers. STUDY DESIGN/MATERIALS AND METHODS: A 31 item survey was developed and sent to 650 members of the Sturge-Weber Foundation. The survey included questions regarding four domains: demographics, disease severity, laser experience, and perceptions and behaviors. Logistic regression models and bivariate analyses were conducted to analyze the results. RESULTS: Among the 123 respondents, earlier initiation of laser treatments was associated with greater birthmark satisfaction. Overall satisfaction increased up to 20 treatments and then leveled off. Color satisfaction increased up to 100 laser treatments; however, the flatness of the PWB was not associated with the number of laser treatments. The perceived benefits of lasers were not associated with the number of lifetime treatments or with spending. However, the perceived susceptibility was associated with greater spending on travel and medical expenses. CONCLUSION: The results of our survey provide insight into SWS patient experiences, beliefs, and behaviors regarding laser therapy. Further exploration of these variables may allow for the improvement of the care experience. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Backmapping coarse-grained macromolecules: An efficient and versatile machine learning approach.

Multiscale modeling of polymers exchanges information between coarse and fine representations of molecules to capture material properties over a wide range of spatial and temporal scales. Restoring details at a finer scale requires us to generate information following embedded physics and statistics of the models at two different levels of description. Techniques designed to address this persistent challenge balance among accuracy, efficiency, and general applicability. In this work, we present an image-based approach for structural backmapping from coarse-grained to atomistic models with cis-1,4 polyisoprene melts as an illustrative example. Through machine learning, we train conditional generative adversarial networks on the correspondence between configurations at the levels considered. The trained model is subsequently applied to provide predictions of atomistic structures from the input coarse-grained configurations. The effect of different data representation schemes on training and prediction quality is examined. Our proposed backmapping approach shows remarkable efficiency and transferability over different molecular weights in the melt based on training sets constructed from oligomeric compounds. We anticipate that this versatile backmapping approach can be readily extended to other complex systems to provide high-fidelity initial configurations with minimal human intervention.

"Live Sun Smart!" Testing the effectiveness of a sun safety program for middle schoolers.

BACKGROUND: Skin cancer is a well-recognized public health issue, and primary prevention is the most effective strategy for reducing skin cancer risk. The current recommendations are that behavioral counseling for sun safety measures is most beneficial and effective for children and adolescents and that targeting this population at primary and middle schools is the ideal intervention strategy to increase sun-protective behaviors and reduce UV exposure, sunburn incidence, and formation of new moles. Numerous studies on the effectiveness of school-based sun safety interventions among elementary and middle school students have shown an increase in sun safety knowledge, attitudes, and behaviors following the intervention. OBJECTIVE: To conduct a pilot feasibility study of "Live Sun Smart!," (LSS) a school-based, multicomponent, interactive sun safety presentation, at changing sun safety knowledge, attitudes, and behaviors among middle school students. METHODS: A non-randomized, single-group pretest-posttest interventional pilot study of the LSS program among children enrolled in grade 6. RESULTS: After exposure to LSS, participants were more likely to give correct answers to knowledge-based sun safety questions and to report negative attitudes toward tanning. Minimal and not significant changes were found in self-reported sun safety behaviors, though students did report an intention to change behaviors following the intervention. Participants were satisfied with the program and believed it increased their sun safety knowledge. CONCLUSION: Live Sun Smart! appears to be an effective school-based, multicomponent sun safety program for improving sun safety knowledge and attitudes toward tanning among middle school students in this initial test of it. The strengths and weaknesses of this pilot study have implications for future research.

Pediatric procedural dermatology.

Pediatric procedural dermatology is a broad and emerging field. Pediatric patients often present with unique diagnoses, and procedures in this population often require special tools. In addition, performing procedures on infants, children, and teenagers requires special considerations, skill sets, and knowledge. This article provides a brief overview of decision-making processes, common diagnoses, and common procedures performed by dermatologists in this patient population.

Pain and Pruritus: a study of their similarities and differences.

Pruritus is one of the most common dermatologic complaints and, as the most common dermatologic symptom, is a major contributor to frequent dermatology visits. Chronic pruritus mirrors another major medical condition faced by millions of Americans each year - chronic pain. In older literature, pain and pruritus were thought to have been conveyed by the same C fiber, and the proportion contributing to pruritus was just a small subset of this general fiber. Overall, pain and pruritus share many integral similarities. Although these sensations both initiate the body's awareness to injury, pain and itch may have evolved for sensing different damages such as a burrowing parasite or a noxious stimulus, respectively. This seems to have been validated through analyses of their pathophysiology, acute and chronic conditions, and treatment modalities. However, their symptoms and intrinsic mechanisms vary considerably. It is important to view pruritus in more of an overall, whole body experience, rather than just the sensory aspect. Future studies should investigate the psychological treatment of chronic pruritus, considering the immense similarities with its chronic pain counterpart.

Structural racism and its influence on the severity of atopic dermatitis in African American children.

BACKGROUND/OBJECTIVES: Atopic dermatitis (AD) is the most common skin disease of childhood and is often more severe in African American than white children. The reason for this disparity is unknown, but recent research indicates that it may be due to a combination of environmental and genetic factors. The objective of this article was to explore the relationship between measures of structural racism and residential segregation within pediatric AD. METHODS: An in-office, online survey consisting of 58 questions spanning 5 domains (demographics, in-home crowding, community crowding, air quality, and litter) was administered to a convenience sample of 201 pediatric AD patients (age 0-18 years). Survey data were geocoded and linked to a measure of structural racism (ie, residential segregation). RESULTS: African American children were more likely to live in rented homes, be in lower income families, have caregivers with lower educational attainment, and be exposed to tobacco smoke. The same factors that were associated with worse AD severity in this study were also found in published literature, emphasizing the role of social determinants of health and racial differences in AD severity. Additionally, this study found that living in highly segregated communities was more likely to be associated with severe AD in African American children. CONCLUSIONS: Consistent with reported literature, socioeconomic status, race, and the physical environment appear to affect AD severity. This investigation adds structural racism as an important community characteristic that likely has significant effects on AD severity for African American Children.

Idiopathic, Refractory Sweet's Syndrome Associated with Common Variable Immunodeficiency: a Case Report and Literature Review.

PURPOSE OF REVIEW: Sweet's syndrome (SS) is classically considered a hypersensitivity reaction often associated with autoimmune disorders and malignancy. SS has also been increasingly reported to occur with immunodeficiencies. We present a case of treatment-refractory, systemic SS as the initial manifestation in a young child with common variable immunodeficiency (CVID). We also review current literature about SS and concurrent immunodeficiencies and autoimmunity in CVID patients. RECENT FINDINGS: Few case reports exist regarding the co-occurrence of Sweet's syndrome and primary immunodeficiencies. SS is characterized by a pro-inflammatory state with a neutrophil predominance resulting in a spectrum of clinical manifestations. CVID is a multifactorial antibody deficiency that can be associated with autoimmunity, which some studies have proposed to be secondary to altered CD21 expression. SS occurring in patients with CVID has been infrequently reported, and one case study demonstrated improvement of Sweet's associated skin lesions with immunoglobulin replacement. In our case, the patient had multi-system SS refractory to multiple immunomodulatory therapies. To our knowledge, this is the first report of the effective and safe use of intravenous tocilizumab and oral lenalidomide to treat SS in a child with CVID. Immunoglobulin replacement reduced the frequency of infections and may have contributed to the opportunity to wean the immunosuppressive therapies for Sweet's syndrome. Sweet's syndrome as an initial manifestation of co-occurring immunodeficiencies is rare, and providers need a high index of suspicion. In addition, treatment of SS associated with an immunodeficiency can be a challenge. Treatment with immunoglobulin replacement reduces the frequency of infections, and in some patients with concurrent SS may improve skin lesions and reduce the need for immunomodulator therapy. Further study is necessary to better understand the pathogenesis of CVID in patients with SS and to identify possible biomarkers that predict who with SS are at risk for developing hypogammaglobulinemia.