Jee-Young Park

Comparative Analysis between Homoeologous Genome Segments of Brassica napus and Its Progenitor Species Reveals Extensive Sequence-Level Divergence

Homoeologous regions of Brassica genomes were analyzed at the sequence level. These represent segments of the Brassica A genome as found in Brassica rapa and Brassica napus and the corresponding segments of the Brassica C genome as found in Brassica oleracea and B. napus. Analysis of synonymous base substitution rates within modeled genes revealed a relatively broad range of times (0.12 to 1.37 million years ago) since the divergence of orthologous genome segments as represented in B. napus and the diploid species. Similar, and consistent, ranges were also identified for single nucleotide polymorphism and insertion-deletion variation. Genes conserved across the Brassica genomes and the homoeologous segments of the genome of Arabidopsis thaliana showed almost perfect collinearity. Numerous examples of apparent transduplication of gene fragments, as previously reported in B. oleracea, were observed in B. rapa and B. napus, indicating that this phenomenon is widespread in Brassica species. In the majority of the regions studied, the C genome segments were expanded in size relative to their A genome counterparts. The considerable variation that we observed, even between the different versions of the same Brassica genome, for gene fragments and annotated putative genes suggest that the concept of the pan-genome might be particularly appropriate when considering Brassica genomes.

Correlation of clinical features and skin barrier function in adolescent and adult patients with atopic dermatitis

Backgroundu2002 Xerotic changes in atopic skin are considered to be related to a decrease in the water permeability barrier. Whether abnormal skin barrier function is the main cause of atopic dermatitis (AD) or a secondary change of the disease is still controversial. Noninvasive bioengineering methods, including the measurement of the transepidermal water loss (TEWL) and water capacitance, have been commonly used to evaluate skin barrier function.

Are there predominant strains and toxins of Staphylococcus aureus in atopic dermatitis patients? Genotypic characterization and toxin determination of S. aureus isolated in adolescent and adult patients with atopic dermatitis

The colonization of Staphylococcus aureus is one of the most important aggravating factors of atopic dermatitis (AD). Until now, the importance of S. aureus in AD and a positive correlation between colonization with S. aureus and clinical severity/skin barrier function has been demonstrated. The aim of this study was to determine whether there are certain clones of S. aureus which colonize the skin of AD patients. For this purpose, the genotype of S. aureus isolated from AD patients was examined by newly‐developed typing methods. With 36 strains of S. aureus isolated from 35 patients with AD, spa typing, multi‐locus sequence typing (MLST), and staphylococcal toxin gene assay by multiplex polymerase chain reaction, were performed. Clinical severity and skin barrier function were evaluated with eczema area and severity index (EASI) and with transepidermal water loss (TEWL). Among 36 strains of S. aureus, 14 sequence types (ST) and 20 spa types were identified, suggesting a very heterogeneous genetic composition of S. aureus and the absence of a prevailing genotype in S. aureus colonized with AD patients. Furthermore, there was no specific genotype of S. aureus which was associated with the clinical severity of AD or skin barrier dysfunction. A toxin gene assay, however, showed the predominance of S. aureus strains carrying sea and/or tsst‐1. To the best of our knowledge, this is the first report to show the genetic composition of S. aureus strains isolated from AD patients determined by sequence‐based typing methods.

Flame figures in molluscum contagiosum.

Flame figures represent dermal collagen fibers coated with eosinophilic granules, first described in eosinophilic cellulitis (Wells syndrome). They are known to occur in a variety of other dermatoses such as bullous pemphigoid, eczema, urticaria, myeloproliferative disease, tinea, and arthropod bite reactions, but not in molluscum contagiosum (MC). We found flame figures in an inflamed lesion of molluscum contagiosum in a 10-year-old female. There were multiple pruritic erythematous papules in a linear arrangement on the groin and thigh. Each lesion measured 2 to 3 mm in diameter. The lesions had waxed and waned for about 8 years, so we performed a skin biopsy to rule out the possibility of other diseases (eg, histiocytosis X). On histopathologic examination, many epidermal cells contained large intracytoplasmic inclusion bodies, the so-called molluscum bodies with partial intradermal rupture (Fig. 1). There was a dense infiltrate of lymphohistiocytes and moderate number of eosinophils, especially in the lower half of the dermis and several typical flame figures were found (Fig. 2). Possible explanations of the formation of flame figures include an isolated occurrence, a hypersensitivity response to the invading parasite, or simply a reaction pattern seen with eosinophil-mediated tissue injury. Peters et al 2 have shown that major basic protein, a toxin important in resistance to parasites and the major constituents of eosinophilic granules, may play a role in the tissue injury seen with flame figures. As for another possible causative factor of flame figures, the degree of tissue eosinophilia may be relevant to its formation. Flame figures are also found in bullous pemphigoid with marked tissue eosinophilia and their incidence in bullous pemphigoid is unexpectedly high (8.8%). We suppose that MC, more spe-