Interventions for hand eczema

BackgroundHand eczema is an inflammation of the skin of the hands that tends to run a chronic, relapsing course. This common condition is often associated with itch, social stigma, and impairment in employment. Many different interventions of unknown effectiveness are used to treat hand eczema.ObjectivesTo assess the effects of topical and systemic interventions for hand eczema in adults and children.Search methodsWe searched the following up to April 2018: Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, AMED, LILACS, GREAT, and four trials registries. We checked the reference lists of included studies for further references to relevant trials.Selection criteriaWe included randomised controlled trials (RCTs) that compared interventions for hand eczema, regardless of hand eczema type and other affected sites, versus no treatment, placebo, vehicle, or active treatments.Data collection and analysisWe used standard methodological procedures expected by Cochrane. Primary outcomes were participant‐ and investigator‐rated good/excellent control of symptoms, and adverse events.Main resultsWe included 60 RCTs, conducted in secondary care (5469 participants with mild to severe chronic hand eczema). Most participants were over 18 years old. The duration of treatment was short, generally up to four months. Only 24 studies included a follow‐up period. Clinical heterogeneity in treatments and outcome measures was evident. Few studies performed head‐to‐head comparisons of different interventions. Risk of bias varied considerably, with only five studies at low risk in all domains. Twenty‐two studies were industry‐funded.Eighteen trials studied topical corticosteroids or calcineurin inhibitors; 10 studies, phototherapy; three studies, systemic immunosuppressives; and five studies, oral retinoids. Most studies compared an active intervention against no treatment, variants of the same medication, or placebo (or vehicle). Below, we present results from the main comparisons.Corticosteroid creams/ointments: when assessed 15 days after the start of treatment, clobetasol propionate 0.05% foam probably improves participant‐rated control of symptoms compared to vehicle (risk ratio (RR) 2.32, 95% confidence interval (CI) 1.38 to 3.91; number needed to treat for an additional beneficial outcome (NNTB) 3, 95% CI 2 to 8; 1 study, 125 participants); the effect of clobetasol compared to vehicle for investigator‐rated improvement is less clear (RR 1.43, 95% CI 0.86 to 2.40). More participants had at least one adverse event with clobetasol (11/62 versus 5/63; RR 2.24, 95% CI 0.82 to 6.06), including application site burning/pruritus. This evidence was rated as moderate certainty.When assessed 36 weeks after the start of treatment, mometasone furoate cream used thrice weekly may slightly improve investigator‐rated symptom control compared to twice weekly (RR 1.23, 95% CI 0.94 to 1.61; 1 study, 72 participants) after remission is reached. Participant‐rated symptoms were not measured. Some mild atrophy was reported in both groups (RR 1.76, 95% CI 0.45 to 6.83; 5/35 versus 3/37). This evidence was rated as low certainty.Irradiation with ultraviolet (UV) light: local combination ultraviolet light therapy (PUVA) may lead to improvement in investigator‐rated symptom control when compared to local narrow‐band UVB after 12 weeks of treatment (RR 0.50, 95% CI 0.22 to 1.16; 1 study, 60 participants). However, the 95% CI indicates that PUVA might make little or no difference. Participant‐rated symptoms were not measured. Adverse events (mainly erythema) were reported by 9/30 participants in the narrow‐band UVB group versus none in the PUVA group. This evidence was rated as moderate certainty.Topical calcineurin inhibitors: tacrolimus 0.1% over two weeks probably improves investigator‐rated symptom control measured after three weeks compared to vehicle (14/14 tacrolimus versus 0/14 vehicle; 1 study). Participant‐rated symptoms were not measured. Four of 14 people in the tacrolimus group versus zero in the vehicle group had well‐tolerated application site burning/itching.A within‐participant study in 16 participants compared 0.1% tacrolimus to 0.1% mometasone furoate but did not measure investigator‐ or participant‐rated symptoms. Both treatments were well tolerated when assessed at two weeks during four weeks of treatment.Evidence from these studies was rated as moderate certainty.Oral interventions: oral cyclosporin 3 mg/kg/d probably slightly improves investigator‐rated (RR 1.88, 95% CI 0.88 to 3.99; 1 study, 34 participants) or participant‐rated (RR 1.25, 95% CI 0.69 to 2.27) control of symptoms compared to topical betamethasone dipropionate 0.05% after six weeks of treatment. The risk of adverse events such as dizziness was similar between groups (up to 36 weeks; RR 1.22, 95% CI 0.80 to 1.86, n = 55; 15/27 betamethasone versus 19/28 cyclosporin). The evidence was rated as moderate certainty.Alitretinoin 10 mg improves investigator‐rated symptom control compared with placebo (RR 1.58, 95% CI 1.20 to 2.07; NNTB 11, 95% CI 6.3 to 26.5; 2 studies, n = 781) and alitretinoin 30 mg also improves this outcome compared with placebo (RR 2.75, 95% CI 2.20 to 3.43; NNTB 4, 95% CI 3 to 5; 2 studies, n = 1210). Similar results were found for participant‐rated symptom control: alitretinoin 10 mg RR 1.73 (95% CI 1.25 to 2.40) and 30 mg RR 2.75 (95% CI 2.18 to 3.48). Evidence was rated as high certainty. The number of adverse events (including headache) probably did not differ between alitretinoin 10 mg and placebo (RR 1.01, 95% CI 0.66 to 1.55; 1 study, n = 158; moderate‐certainty evidence), but the risk of headache increased with alitretinoin 30 mg (RR 3.43, 95% CI 2.45 to 4.81; 2 studies, n = 1210; high‐certainty evidence). Outcomes were assessed between 48 and 72 weeks.Authors' conclusionsMost findings were from single studies with low precision, so they should be interpreted with caution. Topical corticosteroids and UV phototherapy were two of the major standard treatments, but evidence is insufficient to support one specific treatment over another. The effect of topical calcineurin inhibitors is not certain. Alitretinoin is more effective than placebo in controlling symptoms, but advantages over other treatments need evaluating.Well‐designed and well‐reported, long‐term (more than three months), head‐to‐head studies comparing different treatments are needed. Consensus is required regarding the definition of hand eczema and its subtypes, and a standard severity scale should be established.The main limitation was heterogeneity between studies. Small sample size impacted our ability to detect differences between treatments

Characterization of leaf apoplastic peroxidases and metabolites in Vigna unguiculata in response to toxic manganese supply and silicon

Previous work suggested that the apoplastic phenol composition and its interaction with apoplastic class III peroxidases (PODs) are decisive in the development or avoidance of manganese (Mn) toxicity in cowpea (Vigna unguiculata L.). This study characterizes apoplastic PODs with particular emphasis on the activities of specific isoenzymes and their modulation by phenols in the Mn-sensitive cowpea cultivar TVu 91 as affected by Mn and silicon (Si) supply. Si reduced Mn-induced toxicity symptoms without affecting the Mn uptake. Blue Native-PAGE combined with Nano-LC-MS/MS allowed identification of a range of POD isoenzymes in the apoplastic washing fluid (AWF). In Si-treated plants Mn-mediated induction of POD activity was delayed. Four POD isoenzymes eluted from the BN gels catalysed both H2O2-consuming and H2O2-producing activity with pH optima at 6.5 and 5.5, respectively. Four phenols enhanced NADH-peroxidase activity of these isoenzymes in the presence of Mn2+ (p-coumaric=vanillic>>benzoic>ferulic acid). p-Coumaric acid-enhanced NADH-peroxidase activity was inhibited by ferulic acid (50%) and five other phenols (50–90%). An independent component analysis (ICA) of the total and apoplastic GC-MS-based metabolome profile showed that Mn, Si supply, and the AWF fraction (AWFH2O, AWFNaCl) significantly changed the metabolite composition. Extracting non-polar metabolites from the AWF allowed the identification of phenols. Predominantly NADH-peroxidase activity-inhibiting ferulic acid appeared to be down-regulated in Mn-sensitive (+Mn, –Si) and up-regulated in Mn-tolerant (+Si) leaf tissue. The results presented here support the previously hypothesized role of apoplastic NADH-peroxidase and its activity-modulating phenols in Mn toxicity and Si-enhanced Mn tolerance

Quantum coherence controls the charge separation in a prototypical artificial light harvesting system

In artificial light harvesting systems the conversion of light into charges or chemical energy happens on the femtosecond time scale and is thought to involve the incoherent jump of an electron from the optical absorber to an electron acceptor. Here we investigate the primary process of electronic charge transfer dynamics in a carotene-porphyrin-fullerene triad, a prototypical elementary component for an artificial light harvesting system combining coherent femtosecond spectroscopy and first-principles quantum dynamics simulations. Our experimental and theoretical results provide strong evidence that the driving mechanism of the photoinduced current generation cycle is a quantum-correlated wavelike motion of electrons and nuclei on a timescale of few tens of femtoseconds. We furthermore highlight the fundamental role played by the interface between the light-absorbing chromophore and the charge acceptor in triggering the coherent wavelike electron-hole splitting. © 2013 IEEE

Comparative Proteomics Analysis of the Root Apoplasts of Rice Seedlings in Response to Hydrogen Peroxide

-responsive proteins in the apoplast of rice seedling roots. stress. response

Evidence-Based Management of Hand Eczema

Hand eczema is a common skin disease with a wide variation in morphology and a complex etiology based on endogenous and exogenous factors.The diagnosis of hand eczema is based on patient history, exposure assessment, physical examination, and the results of patch testing. Management of hand eczema starts with education of the patient on the etiology of the disease, and the needed changes in behavior regarding skin care and preventive measures, and avoidance of relevant exposure factors. In many cases, medical treatment is needed for successful management of the disease; use of medication can only be successful with proper education and avoidance of relevant exposure

Herbicide resistance-endowing ACCase gene mutations in hexaploid wild oat (Avena fatua): insights into resistance evolution in a hexaploid species

Many herbicide-resistant weed species are polyploids, but far too little about the evolution of resistance mutations in polyploids is understood. Hexaploid wild oat (Avena fatua) is a global crop weed and many populations have evolved herbicide resistance. We studied plastidic acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicide resistance in hexaploid wild oat and revealed that resistant individuals can express one, two or three different plastidic ACCase gene resistance mutations (Ile-1781-Leu, Asp-2078-Gly and Cys-2088-Arg). Using ACCase resistance mutations as molecular markers, combined with genetic, molecular and biochemical approaches, we found in individual resistant wild-oat plants that (1) up to three unlinked ACCase gene loci assort independently following Mendelian laws for disomic inheritance, (2) all three of these homoeologous ACCase genes were transcribed, with each able to carry its own mutation and (3) in a hexaploid background, each individual ACCase resistance mutation confers relatively low-level herbicide resistance, in contrast to high-level resistance conferred by the same mutations in unrelated diploid weed species of the Poaceae (grass) family. Low resistance conferred by individual ACCase resistance mutations is likely due to a dilution effect by susceptible ACCase expressed by homoeologs in hexaploid wild oat and/or differential expression of homoeologous ACCase gene copies. Thus, polyploidy in hexaploid wild oat may slow resistance evolution. Evidence of coexisting non-target-site resistance mechanisms among wild-oat populations was also revealed. In all, these results demonstrate that herbicide resistance and its evolution can be more complex in hexaploid wild oat than in unrelated diploid grass weeds. Our data provide a starting point for the daunting task of understanding resistance evolution in polyploids

Mechanism and Enantioselectivity in Palladium-Catalyzed Conjugate Addition of Arylboronic Acids to β‑Substituted Cyclic Enones: Insights from Computation and Experiment

Enantioselective conjugate additions of arylboronic acids to β-substituted cyclic enones have been previously reported from our laboratories. Air- and moisture-tolerant conditions were achieved with a catalyst derived in situ from palladium(II) trifluoroacetate and the chiral ligand (S)-t-BuPyOx. We now report a combined experimental and computational investigation on the mechanism, the nature of the active catalyst, the origins of the enantioselectivity, and the stereoelectronic effects of the ligand and the substrates of this transformation. Enantioselectivity is controlled primarily by steric repulsions between the t-Bu group of the chiral ligand and the α-methylene hydrogens of the enone substrate in the enantiodetermining carbopalladation step. Computations indicate that the reaction occurs via formation of a cationic arylpalladium(II) species, and subsequent carbopalladation of the enone olefin forms the key carbon–carbon bond. Studies of nonlinear effects and stoichiometric and catalytic reactions of isolated (PyOx)Pd(Ph)I complexes show that a monomeric arylpalladium–ligand complex is the active species in the selectivity-determining step. The addition of water and ammonium hexafluorophosphate synergistically increases the rate of the reaction, corroborating the hypothesis that a cationic palladium species is involved in the reaction pathway. These additives also allow the reaction to be performed at 40 °C and facilitate an expanded substrate scope

Molecular properties of deep-sea dissolved organic matter are predictable by the central limit theorem: evidence from tandem FT-ICR-MS

The reason behind the millennial stability of marine dissolved organic matter (DOM) is subject of controversial discussion. It may be derived by either the occurrence of mainly stable chemical structures or concentrations of individual DOM molecules too low for efficient microbial growth. One of the major challenges in solving this enigma is that, to date, full structural elucidation of DOM remains impossible. Ultrahigh-resolution mass spectrometry can resolve the composition of DOM on a molecular formula level, but the molecular diversity of the isomers behind each formula is unknown. The objective of our study was to fill this gap of knowledge. Molecular fragmentation experiments were performed via Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) on single substances and molecular formulae isolated from deep-sea DOM. We estimated carboxyl (COOH) content with help of two novel measures, one derived from molecular formula information alone and one from fragment ion intensities. For the carboxyl content of single substances, they were poor predictors and fragment ion intensities were highly sensitive to structural properties. For natural DOM, on the contrary, both parameters were highly significantly correlated, despite obvious structural differences between the molecular formulae considered in this study. By using a model approach based on the central limit theorem, we were able to show that the observed fragment ion intensities of DOM may be explained by intrinsic averaging. These results are clear experimental evidence that many isomers exist per molecular formula. Model calculations showed that the observable molecular properties of DOM apparently emerged as averages of multiple isomers according to the central limit theorem. Structural differences between isomers that would reduce the accuracy of our measures for carboxyl content lost their effect due to averaging. Our model calculations based on the central limit theorem indicated that there are at least 100,000 different compounds in DOM each present in seawater at picomolar concentrations