Do-Won Kim

Expression of brain-derived neurotrophic factor in rat dorsal root ganglia, spinal cord and gracile nuclei in experimental models of neuropathic pain

Chronic constriction injury of the sciatic nerve and lumbar L5 and L6 spinal nerve ligation provide animal models for pain syndromes accompanying peripheral nerve injury and disease. In the present study, we evaluated changes in brain-derived neurotrophic factor (BDNF) immunoreactivity in the rat L4 and L5 dorsal root ganglia (DRG) and areas where afferents from the DRG terminates (the L4/5 spinal cord and gracile nuclei) in these experimental models of neuropathic pain. Chronic constriction injury induced significant increase in the percentage of small, medium and large BDNF-immunoreactive neurons in the ipsilateral L4 and L5 DRG. Following spinal nerve ligation, the percentage of large BDNF-immunoreactive neurons increased significantly, and that of small BDNF-immunoreactive neurons decreased markedly in the ipsilateral L5 DRG, while that of BDNF-immunoreactive L4 DRG neurons of all sizes showed marked increase. Both chronic constriction injury and spinal nerve ligation induced significant increase in the number of BDNF-immunoreactive axonal fibers in the superficial and deeper laminae of the L4/5 dorsal horn and the gracile nuclei on the ipsilateral side. Considering that BDNF may modulate nociceptive sensory inputs and that injection of antiserum to BDNF significantly reduces the sympathetic sprouting in the DRG and allodynic response following sciatic nerve injury, our results also may suggest that endogenous BDNF plays an important role in the induction of neuropathic pain after chronic constriction injury and spinal nerve ligation. In addition, the increase of BDNF in L4 DRG may contribute to evoked pain which is known to be mediated by input from intact afferent from L4 DRG following L5 and L6 spinal nerve ligation.

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.

TSLP induces mast cell development and aggravates allergic reactions through the activation of MDM2 and STAT6.

Thymic stromal lymphopoietin (TSLP) is known to promote T helper type 2 cell-associated inflammation. Mast cells are major effector cells in allergic inflammatory responses. We noted that the population and maturation of mast cells were reduced in TSLP-deficient mice (TSLP-/-). Thus, we hypothesized that TSLP might affect mast cell development. We found that TSLP induced the proliferation and differentiation of mast cells from bone marrow progenitors. TSLP-induced mast cell proliferation was abolished by depletion of mouse double minute 2 (MDM2) and signal transducers and activators of transcription 6 (STAT6), as an upstream activator of MDM2. TSLP-/-, in particular, had a considerable deficit in the expression of MDM2 and STAT6. Also, the TSLP deficiency attenuated mast cell-mediated allergic reactions through the downregulation of STAT6 and MDM2. In an antibody microarray chip analysis, MDM2 expression was increased in atopic dermatitis patients. These observations indicate that TSLP is a factor for mast cell development, and that it aggravates mast cell-mediated immune responses.

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.

Detection of human papillomavirus 60 in epidermal cysts of nonpalmoplantar location

Human papillomavirus (HPV) types 57 and 60 are associated with epidermal cysts of palmoplantar location (PPECs). Recently, there was a report of HPV 60 in a wart located in a nonpalmoplantar area as a possible precursor of a nonpalmoplantar epidermal cyst (NPPEC). There has been no study that has examined the presence and frequency of HPV in ordinary NPPECs. We reviewed 63 cases of epidermal cysts, including 59 NPPECs and 4 PPECs. After routine histopathologic review, polymerase chain reaction (PCR) of extracted DNA, sequencing of PCR products, and, finally, a homology search were undertaken. As a result, 9 of 63 (14.3%) cysts, including 6 of 59 NPPECs (10.2%), showed a positive reaction on PCR. By homology search after PCR, all were demonstrated as HPV 60. For NPPECs, no variables, including some histopathologic features, are significantly related to the presence of HPV 60 in univariate or multivariate analysis (P > 0.05).

Fragrance contact dermatitis in Korea: a joint study

The purpose of this study is to determine the frequency of responses to selected fragrances in patients with suspected fragrance allergy and to evaluate the risk factors. 9 dermatology departments of university hospitals have participated in this study for the past 1 year. To determine allergic response to fragrances, 18 additional fragrances in addition to the Korean standard and a commercial fragrance series were patch‐tested in patients with suspecting cosmetic contact dermatitis. Over 80% of the patients were women, and the most common site was the face. Cinnamic alcohol and sandalwood oil (Santalum album L.) showed high frequencies of positive responses. Of the specific fragrances, ebanol, α‐isomethyl‐ionone (methyl ionone‐γ) and Lyral® (hydroxyisohexyl 3‐cyclohexane carboxdaldehyde) showed high positive responses. We compared the results obtained during this study with those of other studies and concluded that including additional fragrance allergens may be useful for the detection of fragrance allergy.

Expression of brain-derived neurotrophic factor in catecholaminergic neurons of the rat lower brainstem after colchicine treatment or hemorrhage

Widespread brain-derived neurotrophic factor messenger RNA expression has been detected in the region of catecholamine groups of the rat lower brainstem, while few brain-derived neurotrophic factor-immunoreactive cells were found in this area. In the present study, a double-color immunofluorescence technique for brain-derived neurotrophic factor and tyrosine hydroxylase after colchicine treatment was employed to evaluate the possible presence of brain-derived neurotrophic factor immunoreactivity in the catecholaminergic cells of the rat lower brainstem. We detected many new brain-derived neurotrophic factor-immunoreactive cells in the A1, A2, A4, A6-A10 and C1-C3 cell groups and in the other lower brainstem nuclei where, without colchicine treatment, brain-derived neurotrophic factor messenger RNA was expressed, but not brain-derived neurotrophic factor immunoreactivity. In addition, the catecholaminergic neurons were found to express brain-derived neurotrophic factor immunoreactivity with the co-existence being greatest, in percentage terms, in medullary catecholaminergic cell groups. Hypotensive hemorrhage, which activates medullary catecholaminergic neurons, induced the expression of brain-derived neurotrophic factor immunoreactivity in catecholaminergic neurons (A1/C1 and C2). The results demonstrate that brain-derived neurotrophic factor is regulated by neuronal activity in medullary catecholaminergic cell groups involved in central cardiovascular regulation.

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-

Phototrichogram analysis of normal scalp hair characteristics with aging

BACKGROUNDnPhototrichogram analysis of normal scalp hair characteristics in Asian populations is not well characterized.nnnOBJECTIVEnTo investigate the normal hair characteristics of South Koreans using a phototrichogram.nnnMETHODSnWe enrolled 674 males and 683 females between the ages of 10 and 69. Hair density, thickness and the white hair percentage were measured via phototrichogram. Six scalp sites, including front, top, the peak between top and back, back, and the right and left sides were targeted.nnnRESULTSnThe mean hair density, hair thickness, and the white hair percentages were not significantly different between genders at any scalp site. The mean hair density and thickness were significantly different according to scalp sites. Hair density declined with age, especially at the peak between the top and back. Males and females showed different patterns of aging in hair density. Hair thickness changed little with age. Mean hair thickness generally tended to increase until the 20s, reach a plateau between the 20s and 50s, and decrease after the 50s. The mean white hair percentages were 1.84 ± 4.24% in males and 1.66 ± 4.21% in females. The mean white hair percentages were significantly increased in subjects over 40 years of age.nnnCONCLUSIONnWe described the normal characteristics and aging patterns of scalp hair in a Korean population.

Change in Antimicrobial Susceptibility of Skin-Colonizing Staphylococcus aureus in Korean Patients with Atopic Dermatitis during Ten-Year Period

Background A small subset of adolescents atopic dermatitis (AD) tends to persist. This also leads to get more antibiotics exposure with advancing years. Antibiotic resistance has been regarded as a serious problem during Staphylococcus aureus treatment, especially methicillin-resistant S. aureus (MRSA). Objective It was investigated the S. aureus colonization frequency in the skin lesions and anterior nares of adolescent AD patients and evaluated the changes in S. aureus antimicrobial susceptibility for years. Methods Patients who visited our clinic from September 2003 to August 2005 were classified into group A, and patients who visited from August 2010 to March 2012 were classified into group B. To investigate the differences with regard to patients age and disease duration, the patients were subdivided into groups according to age. Lesional and nasal specimens were examined. Results Among the 295 AD patients, the total S. aureus colonization rate in skin lesions was 66.9% (95/142) for group A and 78.4% (120/153) for group B. No significant changes in the systemic antimicrobial susceptibilities of S. aureus strains isolated from adolescent AD patients were observed during about 10-year period. The increased trend of MRSA isolation in recent adolescent AD outpatients suggest that the community including school could be the source of S. aureus antibiotic resistance and higher fusidic acid resistance rates provides evidence of imprudent topical use. Conclusion Relatively high MRSA isolation and fusidic acid resistance rates in recent AD patients suggest that the community harbors antibiotic-resistant S. aureus.