143 research outputs found

    Constraints, Histones, and the 30 Nanometer Spiral

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    We investigate the mechanical stability of a segment of DNA wrapped around a histone in the nucleosome configuration. The assumption underlying this investigation is that the proper model for this packaging arrangement is that of an elastic rod that is free to twist and that writhes subject to mechanical constraints. We find that the number of constraints required to stabilize the nuclesome configuration is determined by the length of the segment, the number of times the DNA wraps around the histone spool, and the specific constraints utilized. While it can be shown that four constraints suffice, in principle, to insure stability of the nucleosome, a proper choice must be made to guarantee the effectiveness of this minimal number. The optimal choice of constraints appears to bear a relation to the existence of a spiral ridge on the surface of the histone octamer. The particular configuration that we investigate is related to the 30 nanometer spiral, a higher-order organization of DNA in chromatin.Comment: ReVTeX, 15 pages, 18 figure

    Global Guidelines in Dermatology Mapping Project (GUIDEMAP):a scoping review of dermatology clinical practice guidelines

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    Background Clinical practice guidelines (CPGs) play a critical role in standardizing and improving treatment outcomes based on the available evidence. It is unclear how many CPGs are available globally to assist clinicians in the management of patients with skin disease. Objectives To search for and identify CPGs for dermatological conditions with the highest burden globally. Methods We adapted a list of 12 dermatological conditions with the highest burden from the Global Burden of Disease (GBD) study 2019. A systematic literature search was done to identify CPGs published between October 2014 to October 2019. The scoping review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Results A total of 226 CPGs were included. Melanoma had the greatest representation in the CPGs, followed by dermatitis and psoriasis. Skin cancers had a relatively high CPG representation but with lower GBD disease burden ranking. There was an uneven distribution by geographical region, with resource-poor settings being under-represented. The skin disease categories of the CPGs correlated weakly with the GBD disability-adjusted life-years metrics. Eighty-nine CPGs did not have funding disclosures and 34 CPGs were behind a paywall. Conclusions The global production of dermatology CPGs showed wide variation in geographical representation, article accessibility and reporting of funding. The number of skin disease CPGs were not commensurate with its disease burden. Future work will critically appraise the methodology and quality of dermatology CPGs and lead to the production of an accessible online resource summarizing these findings.Dermatology-oncolog

    The effectiveness of antibacterial therapeutic clothing compared with non-antibacterial therapeutic clothing in patients with moderate-to-severe atopic dermatitis: A randomized controlled, observer-blind pragmatic trial (ABC trial)

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    BACKGROUND Increased Staphylococcus aureus (SA) colonization is considered an important factor in the pathogenesis of atopic dermatitis (AD). Antibacterial therapeutic clothing aims to reduce SA colonization and AD inflammation, however its role in the management of AD remains poorly understood. OBJECTIVE To investigate the effectiveness of antibacterial therapeutic clothing plus standard topical treatment in patients with moderate-to-severe AD, compared to standard therapeutic clothing plus standard topical treatment. If effectiveness is demonstrated, the cost-effectiveness will be evaluated. METHODS A pragmatic, double-blinded, multicenter, randomized, controlled, trial (NCT04297215) was conducted in patients of all ages with moderate-to-severe AD. Patients were centrally randomized 1:1:1 to receive standard therapeutic clothing, antibacterial clothing based on chitosan or silver. The primary outcome was the between-group difference in Eczema Area and Severity Index (EASI) measured over 52 weeks. Secondary outcomes included patient-reported outcomes, topical corticosteroid use, SA colonization, safety, and cost-effectiveness. Outcomes were assessed by means of (generalized) linear mixed model analyses. RESULTS Between March 16, 2020, and December 20, 2021, 171 patients were enrolled. In the analyses 159 patients were included (n=54 in the standard therapeutic clothing group, n=50 in the chitosan group and n=55 in the silver group). Adherence was high (median: 7 nights/week, IQR: 3-7). Median EASI scores at baseline, 4, 12, 26 and 52 weeks were in the standard therapeutic clothing group 11.8, 4.3, 4.6, 4.2, 3.6 compared to 11.3, 5.0, 3.0, 3.0, 4.4 in the chitosan and 11.6, 5.0, 5.4, 4.6 and 5.8 in the silver group. No differences in EASI over 52 weeks between the standard therapeutic clothing, chitosan (-0.1, 95%CI: -0.3 to 0.2, p=0.53), and silver group (-0.1, 95%CI: -0.3 to 0.2, p=0.58) were found. However, a small significant (P=0.035) group-by-time interaction effect between the standard and silver group was found, in which the silver group performed worse after 26 weeks. No differences between groups were found in patient-reported outcomes, topical corticosteroid use, SA skin colonization, and healthcare utilization. No severe adverse events or silver absorption were observed. CONCLUSIONS The results of this study suggest no additional benefits of antibacterial agents in therapeutic clothing in patients with moderate-to-severe AD

    European guideline (EuroGuiDerm) on atopic eczema - part II: non-systemic treatments and treatment recommendations for special AE patient populations.

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    The evidence- and consensus-based guideline on atopic eczema was developed in accordance with the EuroGuiDerm Guideline and Consensus Statement Development Manual. Four consensus conferences were held between December 2020 and July 2021. Twenty-nine experts (including clinicians and patient representatives) from 12 European countries participated. This second part of the guideline includes recommendations and detailed information on basic therapy with emollients and moisturizers, topical anti-inflammatory treatment, antimicrobial and antipruritic treatment and UV phototherapy. Furthermore, this part of the guideline covers techniques for avoiding provocation factors, as well as dietary interventions, immunotherapy, complementary medicine and educational interventions for patients with atopic eczema and deals with occupational and psychodermatological aspects of the disease. It also contains guidance on treatment for paediatric and adolescent patients and pregnant or breastfeeding women, as well as considerations for patients who want to have a child. A chapter on the patient perspective is also provided. The first part of the guideline, published separately, contains recommendations and guidance on systemic treatment with conventional immunosuppressive drugs, biologics and janus kinase (JAK) inhibitors, as well as information on the scope and purpose of the guideline, and a section on guideline methodology

    Effectiveness of antibacterial therapeutic clothing vs. nonantibacterial therapeutic clothing in patients with moderate-to-severe atopic dermatitis: a randomized controlled observer-blind pragmatic trial (ABC trial)

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    Background Increased Staphylococcus aureus (SA) colonization is considered an important factor in the pathogenesis of atopic dermatitis (AD). Antibacterial therapeutic clothing aims to reduce SA colonization and AD inflammation; however, its role in the management of AD remains poorly understood. Objectives To investigate the effectiveness of antibacterial therapeutic clothing+standard topical treatment in patients with moderate-to-severe AD vs. standard therapeutic clothing+standard topical treatment; and, if effectiveness was demonstrated, to demonstrate its cost-effectiveness. Methods A pragmatic double-blinded multicentre randomized controlled trial (NCT04297215) was conducted in patients of all ages with moderate-to-severe AD. Patients were centrally randomized 1:1:1 to receive standard therapeutic clothing or antibacterial clothing based on chitosan or silver. The primary outcome was the between-group difference in Eczema Area and Severity Index (EASI) measured over 52 weeks. Secondary outcomes included patient-reported outcomes (PROs), topical corticosteroid (TCS) use, SA colonization, safety and cost-effectiveness. Outcomes were assessed by means of (generalized) linear mixed-model analyses. Results Between 16 March 2020 and 20 December 2021, 171 patients were enrolled. In total, 159 patients were included (54 in the standard therapeutic clothing group, 50 in the chitosan group and 55 in the silver group). Adherence was high [median 7 nights a week wear (interquartile range 3–7)]. Median EASI scores at baseline and at 4, 12, 26 and 52 weeks were 11.8, 4.3, 4.6, 4.2 and 3.6, respectively, in the standard therapeutic clothing group vs. 11.3, 5.0, 3.0, 3.0 and 4.4, respectively, in the chitosan group, and 11.6, 5.0, 5.4, 4.6 and 5.8, respectively, in the silver group. No differences in EASI over 52 weeks between the standard therapeutic clothing group, the chitosan group [–0.1, 95% confidence interval (CI) –0.3 to 0.2; P=0.53] or the silver group (–0.1, 95% CI –0.3 to 0.2; P=0.58) were found. However, a small significant group×time interaction effect between the standard and silver groups was found (P=0.03), in which the silver group performed worse after 26 weeks. No differences between groups were found in PROs, TCS use, SA skin colonization and healthcare utilization. No severe adverse events or silver absorption were observed. Conclusions The results of this study suggest no additional benefits of antibacterial agents in therapeutic clothing in patients with moderate-to-severe AD

    European guideline (EuroGuiDerm) on atopic eczema – part II: non-systemic treatments and treatment recommendations for special AE patient populations

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    The evidence- and consensus-based guideline on atopic eczema was developed in accordance with the EuroGuiDerm Guideline and Consensus Statement Development Manual. Four consensus conferences were held between December 2020 and July 2021. Twenty-nine experts (including clinicians and patient representatives) from 12 European countries participated. This second part of the guideline includes recommendations and detailed information on basic therapy with emollients and moisturizers, topical anti-inflammatory treatment, antimicrobial and antipruritic treatment and UV photo- therapy. Furthermore, this part of the guideline covers techniques for avoiding provocation factors, as well as dietaryinterventions, immunotherapy, complementary medicine and educational interventions for patients with atopic eczema and deals with occupational and psychodermatological aspects of the disease. It also contains guidance on treatment for paediatric and adolescent patients and pregnant or breastfeeding women, as well as considerations for patients who want to have a child. A chapter on the patient perspective is also provided. The first part of the guideline, published sepa- rately, contains recommendations and guidance on systemic treatment with conventional immunosuppressive drugs, biologics and janus kinase (JAK) inhibitors, as well as information on the scope and purpose of the guideline, and a sec- tion on guideline methodology. Received: 17 February 2022; Accepted: 3 June 202

    TREatment of ATopic eczema (TREAT) Registry Taskforce : Consensus on how and when to measure the core dataset for atopic eczema treatment research registries

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    BACKGROUND: Comparative, real-life and long-term evidence on the effectiveness and safety of phototherapy and systemic therapy in moderate-to-severe atopic eczema (AE) is limited. Such data must come from well-designed prospective patient registries. Standardization of data collection is needed for direct comparisons and data pooling. OBJECTIVES: To reach a consensus on how and when to measure the previously defined domain items of the TREatment of ATopic eczema (TREAT) Registry Taskforce core dataset for research registries for paediatric and adult patients with AE. METHODS: Proposals for the measurement instruments were based on recommendations of the Harmonising Outcome Measures for Eczema (HOME) initiative, the existing AE database of TREATgermany, systematic reviews of the literature and expert opinions. The proposals were discussed at three face-to-face consensus meetings, one teleconference and via e-mail. The frequency of follow-up visits was determined by an expert survey. RESULTS: A total of 16 experts from seven countries participated in the 'how to measure' consensus process and 12 external experts were consulted. A consensus was reached for all domain items on how they should be measured by assigning measurement instruments. A minimum follow-up frequency of initially 4 weeks after commencing treatment, then every 3 months while on treatment and every 6 months while off treatment was defined. CONCLUSIONS: This core dataset for national AE research registries will aid in the comparability and pooling of data across centres and country borders, and enables international collaboration to assess the long-term effectiveness and safety of phototherapy and systemic therapy used in patients with AE. What's already known about this topic? Comparable, real-life and long-term data on the effectiveness and safety of phototherapy and systemic therapy in patients with atopic eczema (AE) are needed. There is a high diversity of outcomes and instruments used in AE research, which require harmonization to enhance comparability and allow data pooling. What does this study add? Our taskforce has reached international consensus on how and when to measure core domain items for national AE research registries. This core dataset is now available for use by researchers worldwide and will aid in the collection of unified data. What are the clinical implications of this work? The data collected through this core dataset will help to gain better insights into the long-term effectiveness and safety of phototherapy and systemic therapy in AE and will provide important information for clinical practice. Standardization of such data collection at the national level will also allow direct data comparisons and pooling across country borders (e.g. in the analysis of treatment-related adverse events that require large patient numbers)
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