353 research outputs found

    Leukonychia: What Can White Nails Tell Us?

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    Changes in nail color can provide important clues of underlying systemic and skin disease. In particular, white discoloration (leukonychia) has a high prevalence with a wide array of potential relevant causes, from simple manicure habits to life-threatening liver or kidney failure. Therefore, a reliable assessment of the patient with leukonychia is essential. In the past, two classifications for leukonychia have been presented. The morphological classifies the nail according to the distribution of the white lines: total, partial, transversal, and longitudinal leukonychia. Mees' and Muehrcke's lines are examples of transversal leukonychia, while Terry's and Lindsay's nails are examples of total and partial leukonychia. The anatomical classifies according to the structure responsible for the white color: the nail plate in true leukonychia, the nail bed in apparent leukonychia, and the surface only in pseudoleukonychia. In this review, both morphological and anatomical features have been combined in an algorithm that enables clinicians to approach leukonychia efficiently and effectively

    Changes in Disease Resistance Phenotypes Associated With Plant Physiological Age Are Not Caused by Variation in R Gene Transcript Abundance

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    Foliar late blight is one of the most important diseases of potato. Foliar blight resistance has been shown to change as a plant ages. In other pathosystems, resistance (R) gene transcript levels appear to be correlated to disease resistance. The cloning of the broad-spectrum, foliar blight resistance gene RB provided the opportunity to explore how foliar blight resistance and R-gene transcript levels vary with plant age. Plants of Solanum bulbocastanum PT29, from which RB, including the native promoter and other flanking regions, was cloned, and S. tuberosum cv. Dark Red Norland (nontransformed and RB-transformed) representing three different developmental stages were screened for resistance to late blight and RB transcript levels. Preflowering plants of all genotypes exhibited the highest levels of resistance, followed by postflowering and near-senescing plants. The RB transgene significantly affected resistance, enhancing resistance levels of all RB-containing lines, especially in younger plants. RB transgene transcripts were detected at all plant ages, despite weak correlation with disease resistance. Consistent transcript levels in plants of different physiological ages with variable levels of disease resistance demonstrate that changes in disease-resistance phenotypes associated with plant age cannot be attributed to changes in R-gene transcript abundance

    Resistance to Ralstonia Solanacearum of sexual hybrids between Solanum commersonii and S. tuberosum

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    This research was carried out to study the levels of bacterial wilt resistance and genetic diversity of (near) pentaploid sexual hybrids between S. commersonii (2n = 2x = 24, 1EBN) and cultivated S. tuberosum. Following artificial inoculations with Ralstonia solanacearum, wilting degree was estimated on a scale from 0 to 4, and seven genotypes of 26 (27%) displaying a S. commersonii like behavior were identified. Latent bacterial colonizations were detected in roots of symptomless S. commersonii and hybrids, whereas no bacterial populations were detected within stems. This suggests that the movement and/or growth of the bacterium in the aerial part were strongly inhibited. A molecular study with AFLP markers clustered hybrids into nine groups and provided evidence that resistant hybrids were slightly more similar to cultivated S. tuberosum than to the wild parent. This is important in view of the re-establishment of the cultivated genetic background through backcrosses. Hybrids displayed good fertility and are being used for further breeding efforts

    Fertilization fitness and offspring ploidy in 3x x 2x matings in potato.

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    The main objective of the current research was to study the reproductive behaviour of artificial triploid potato hybrids between wild Solanum commersonii and the cultivated potato Solanum tuberosum. When used in 3x 6 2x crosses, triploids gave aneuploid progenies with somatic chromosome number ranging from 29 to 36. Fertilization fitness data suggested that the survival rate of gametes produced by the triploid parents may be related to their chromosome number. In addition, consistent with molecular data, our results indicated that fitness of gametes and chromosome number of progenies are influenced by the genome dosage of interspecific triploids. Since a main route to polyploidy formation is via 2n gametes and triploids, our study may contribute to a better understanding of polyploid plant reproduction, evolution and breeding

    A pilot study of intralesional methotrexate injections versus triamcinolone acetonide in patients affected by nail matrix psoriasis

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    Nail disorders in general are difficult to treat and often frustrating, and this is also the case with nail psoriasis, especially when it is limited to the nails, and not affecting joints. The quality of life of patients with nail psoriasis is negatively affected, owing to the chronic course of the disease and frequent relapses. The purpose of this study was to compare treatment response and maintenance of response during follow-up of 12 patients with nail matrix psoriasis limited to a few nails, who were treated with intralesional injections of either methotrexate (MTX) 25 mg/mL or triamcinolone acetonide 10 mg/mL. Patients were treated every 6 weeks for 24 weeks and followed up for 6 months. Photographic documentation and assessment by Nail Psoriasis Severity Index were performed during each treatment session and at each follow-up visit. At the end of the four treatment sessions, all patients had improvement of their disease, which continued during follow-up, especially for the MTX-treated group

    SCREENING TOMATO GLUTATHIONE S-TRANSFERASE DIVERSITY FOR ASSOCIATION TO DROUGHT STRESS

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    Environmental stresses are one of the main challenges in agriculture, as they significantly limit crop productivity. As a result of global warming and climate change, extreme environmental events and abiotic stresses are expected to increase in intensity and frequency. Selecting tolerant plants for more resilient agro-ecosystems is a promising strategy for mitigating the effects of adverse environments. The cultivated tomato (Solanum lycopersicum L.) has a narrow genetic base, and its reduced genetic diversity hampers the progress of breeding. However, the rediscovery and use of local and wild genetic resources allow useful/beneficial alleles to be identified and used in breeding programs. To improve adaptation to harmful conditions, plants have evolved many molecular and genetics mechanisms, including hormone regulation and the activation of specific gene networks. Among others, glutathione S-transferase (GST) genes have been identified in various plant species and found to be involved in different physiological, developmental and stress modulation pathways. The aim of this research is to add insights into the role of tomato GST genes in the plant response to stress by associating allele diversity with drought tolerance. Tomato GST sequences were characterized in silico showing their diffuse clustering pattern across chromosomes with TAU class GSTs duplicated in tandem and mostly aggregated on chromosomes 7 and 9. To characterize the diversity of selected GSTs, a core collection of 75 tomato accessions was selected based on microsatellite screening from a larger collection of worldwide accessions. The core collection was screened for drought tolerance when 50% of plants showed fruit set on the lower flower truss. At this stage, two different water treatments were applied consisting in the complete restitution of the water lost due to evapo-transpiration (Full Water Restitution FWR) and the restitution of 50% of the water lost (Half Water Restitution HWR). After seven days the plants showed visible sign of drought and the leaves were analyzed for gas exchange and colorimetric variations. A gas exchange analyzer (Licor 6400) was used to measure the assimilation rate of foliar CO2 (µmol CO2 m-2 s-1) and transpiration (mmol H2O m-2 s-1). The colorimetric analysis was carried out with a portable Chroma Meters (Minolta). The eco-physiological data showed a continuous variability of the response to drought throughout the collection and allowed to identify eight tomato accessions combining a lower reduction in CO2 assimilation, transpiration and water use efficiency and higher stability in leaf temperatures and colorimetric variations when challenged with HWR. Enriched libraries for GST loci were prepared based on the specific hybridization of short oligonucleotide primers (20-25 bases). Libraries will be sequenced using next/third generation sequencing technology (Illumina or PacBio). Mapped variants and haplotypes in the GST loci will be integrated with drought tolerant traits and used to identify associations with tolerant phenotypes to additional environmental stresses

    INVESTIGATING THE NUCLEOTIDE DIVERSITY IN THE GLUTATHIONE S-TRANSFERASE GENE FAMILY ACROSS THE TOMATO GENE POOL AND ITS SIGNIFICANCE IN CONTROLLING PLANT RESPONSE TO STRESS

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    The agricultural sector faces a significant challenge in dealing with environmental stresses, which greatly reduce crop productivity. Due to global warming and climate change, abiotic stresses are predicted to become more frequent. In this scenario, to meet a growing global demand for food, breeding crops for enhanced tolerance to harsh environments is promising. The cultivated tomato (Solanum lycopersicum L.) is one of the most important vegetable crops in the world and the genome of its wild relatives Solanum pimpinellifolium, Solanum lycopersicoides and Solanum pennellii have been sequenced and their effective tolerance to extreme environments well documented. However, knowledge about tomato genetic diversity is limited and its phenotypic significance dramatically unpredictable to make its exploitation proficient. Glutathione S-transferase (GST) genes have been identified in numerous plant species and are involved in various physiological, developmental, and stress modulation pathways. The aim of this study was to provide a comprehensive description of the GST nucleotide diversity in the tomato gene pool and contextual mining of functional significance for plant adaptability to challenging stresses. We identified 83 GST genes in Solanum lycopersicum (ITAG 4.1) and their orthologues within the wild relatives. Sequences were analyzed for their exon-intron structures, conserved protein motifs, putative subcellular locations, phylogenetic relationships and duplication events. Interaction networks, promoter and cis-regulatory elements and gene expression profiles were also identified. Phylogenetic analysis enabled grouping GST genes into ten subclasses. Furthermore, protein–protein interaction networks revealed the central role of GST genes controlling the cell redox state. A reference non redundant core collection of 75 tomato genotypes was selected from a larger collection of worldwide accessions genotyped by SSR markers. The core collection was screened for drought tolerance at the fruit set stage on the first flower truss. The leaves were assayed for gas exchange and colorimetric variations and profiled for H2O2, ascorbic acid and antioxidant capacity. The most tolerant and sensitive tomato accessions were selected. Plants were grown in lysimeters where the water supply was managed to apply two levels of soil water potential that is 10-20 kPa in the control treatment and 100-120 kPa for the drought treatment, respectively. To deepen our understanding of the regulatory mechanisms that control photo-assimilation, photo-assimilate allocation and fruit yield and quality under limited levels of available water, leaves, stems and fruit at different ripening stages were collected for RNA-seq analysis. Further bioinformatics analysis will allow us to validate the role of specific GSTs and other key genes in controlling the response of tomato plants to drought and modulating photo-assimilate allocation in sensitive and tolerant genomic backgrounds

    Onychomycosis: Recommendations for Diagnosis, Assessment of Treatment Efficacy, and Specialist Referral. The CONSONANCE Consensus Project

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    Introduction: Onychomycosis is the most common nail disorder in adults, with high recurrence and relapse rates. Its diagnosis may be difficult by non-experts because the clinical signs may overlap with other dermatoses. The treatment may be challenging, as it should be patient-tailored. Methods: An online survey was conducted among European Nail Society (ENS) members to provide recommendations on the diagnosis and assessment of distal lateral subungual onychomycosis (DLSO) in non-specialized clinical environments, as well as recommendations for patient referral. Results: DLSO diagnosis is predominantly based on clinical aspects, and microscopy and fungal culture are commonly employed to establish the diagnosis. Assessment of clinical features is the main method for DLSO follow-up, and the main criterion to define cure is a combination of mycologic cure and clinical cure. The most commonly selected treatments for onychomycosis include oral antifungals, topical antifungals, and nail debridement. According to the nail experts, predisposing factors of DLSO to be evaluated include concurrent tinea pedis diagnosis, immunocompromised status, and diabetes. The minimum clinical aspects to be evaluated for DLSO diagnosis should include subungual hyperkeratosis, white-yellow-orange subungual scales, and absence of salmon-pink coloration. Recommendations for clinical signs that should be evaluated to confirm treatment effectiveness include normal appearance and color of the nail, reduction or absence of scales under the nail, and absence of onycholysis. Recommendations for specialist referral include lack of treatment effectiveness, need of additional therapies, concurrent presence of other diseases or comorbidities, severe DLSO, and presence of a dermatophytoma or involvement of the nail matrix. Conclusions: According to the surveyed nail experts, after evaluating clinical signs and predisposing factors for DLSO, the diagnosis should include subungual hyperkeratosis, nail color (yellow-orange), and onycholysis and thickening. In cases of severe DLSO, when there is treatment failure, concomitant diseases/comorbidities, presence of a dermatophytoma or involvement of the nail matrix, or involvement of several/all nails, referral should be considered

    A Practical Algorithm for the Management of Superficial Folliculitis of the Scalp: 10 Years of Clinical and Dermoscopy Experience

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    Introduction: Superficial folliculitis of the scalp (SFS) is a common complaint in clinical practice, and initial presentation may be difficult to differentiate as they may appear very similar to each other. Objectives: The aim of this thesis is to describe the pathologies that occur clinically as folliculitis of the scalp, identify their causes and characteristics and create a standardized classification. Methods: This is a retrospective clinical, dermoscopic and histopathological study over 10 years of dermatologic consultations. Only individuals with a confirmed diagnosis of SFS (updated diagnostic criteria or biopsy) were included. Results: In this review, we describe the various clinical features of different causes of SFS in ninety-nine cases and divided into infectious due to fungus, bacteria, or virus and inflammatory conditions such as rosacea, acneiform eruption and Ofuji syndrome. Conclusions: The clinician must differentiate SFS from other underlying scarring disorders to prevent poorer outcomes. We created an algorithm to help the clinician reach a proper diagnosis
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