P277 : Epidemiological, clinical, and histopathological characteristics of Riehl`s melanosis

( Chulhyun Yun ),( Ryuha Ryeong ),( Jihoon Kim ),( Joonseok Choi ),( Jinok Baek ),( Joo Young Roh ),( Jongrok Lee ) 대한피부과학회 2014 대한피부과학회 학술발표대회집 Vol.66 No.2

Background: Riehl’s melanosis is a nonpruritic pigmented dermatitis characterized by a brownish gray pigmentation and is almost synonomous with pigmented contact dermatitis of the face, the most common causes of which are sensitizing chemicals in cosmetics. So far, there have only been a few Korean studies of Riehl’s melanosis, which have a limited number of patients. Objectives: The aim of this study is to evaluate the epidemiological, clinical, histopathological characteristics of Riehl’s melanosis in Korean patients. Methods: We retrospectively reviewed the medical records and biopsy specimen of 14 patients who were diagnosed with Riehl’s melanosis. A biopsy specimen was obtained from a pigmented macules, and a patch test in 10 patients was performed. Results: The mean age was 47.4 years (range, 26~68), and the average duration of the lesion was 18.0 months. The face(71.4%) and neck(71.4%) were the most frequently occurring sites of the lesion. Only patients of 14.3% had a systemic disease. Melanophage in papillary dermis (100%) was the most common histopathologic finding. The most positive finding of patch test was nickel sulfate (30.0%), followed by fragrance mix (20.0%), colophony (10.0%), balsam of peru (10.0%). Conclusion: Dermatologists should consider these characteristics in patients with Riehl’s melanosis. Further investigation and follow-up studies are necessary to better understand the epidemiological, clinical, and histopathological findings of Riehl’s melanosis.

P091 : Clinical efficacy of alitretinoin in patients with palmoplantar pustular psoriasis

( Chulhyun Yun ),( Haryeong Ryu ),( Jihoon Kim ),( Joonseok Choi ),( Jinok Baek ),( Jongrok Lee ),( Jooyoung Roh ) 대한피부과학회 2014 대한피부과학회 학술발표대회집 Vol.66 No.2

Background: Palmoplantar pustular psoriasis(PPP) is a chronic inflammatory skin disease which is often resistant to treatment. Oral alitretinoin is a vitamin A derivative that has emerged as a novel treatment for recalcitrant chronic hand eczema. The effect of alitretinoin for recalcitrant PPP is still poorly investigated. Objectives: The aim of this study is to evaluate the therapeutic effect of alitretinoin in recalcitrant PPP. Methods: Six patients with moderate to severe PPP unresponsive to conventional treatment were treated with oral alitretinoin 30mg once daily for 12 weeks. Efficacy was assessed at week 12 by modified Palmoplantar Pusutular Psoriasis And Severity Index (m-PPPASI), Physician’s Global Assessment (PGA), Patient’s Global Assessment (PaGA). Results: At baseline, the mean m-PPPASI was 26.03 (range: 5.0-43.8). The mean m-PPPASI score at week 12 was 3.88 (range: 0-10.7). At week 12, 83.3% (n=5) of patients achieved an m-PPPASI 75. PGA response of ‘clear (n=2, 33.3%)’ or ‘almost clear(n=1, 16.6%)’ was reported in 50.0% of patients. PaGA results were consistent with PGA in 3 patients rating their disease as ‘clear(n=2, 33.3%)’ or ‘almost clear(n=1, 16.7%)’ at the end of treatment. Conclusion: Alitretinoin might be suggested as a new treatment modality for the patients who have failed to respond to conventional therapy. Further randomized controlled study with large number of patients and comparison with conventional treatment is pending.

Effects of Electrical Characteristics on the Non-Rectangular Gate Structure Variations for the Multifinger MOSFETs

Chulhyun Park,Youngkyu Song,Jung Han Kang,Seong-Ook Jung,Ilgu Yun IEEE 2011 IEEE transactions on components, packaging, and ma Vol.1 No.3

<P>In this paper, modeling methodology of electrical characteristics for non-rectangular gate structured multifinger metal-oxide-semiconductor field-effect transistors based on minimum channel length is proposed. The test structures are fabricated and the parasitic model parameters are extracted using the measured data for the proposed model. The proposed model can support better physical explanation than the previously presented integrated length model. The proposed model can precisely explain the electrical characteristics and is supported by theoretical equations for non-rectangular gates, such as the threshold voltage, the saturation voltage, the saturation current, and the leakage current. However, the previous integrated length model cannot sufficiently explain the electrical characteristics for non-rectangular gates although it is sustained by theoretical equations. Furthermore, this paper shows the relationship between gate poly area and the electrical characteristics. As a result, the electrical characteristics are dependent on the variation of the minimum of the gate length, rather than the profile of gate length variation.</P>

Variation Analysis of DC Characteristics for Multi-Finger MOSFETs

Chulhyun Park,Junghan Kang,Seong-Ook Jung,Ilgu Yun 대한전자공학회 2008 ICEIC:International Conference on Electronics, Inf Vol.1 No.1

Variation analysis of the DC characteristics for multi-finger MOSFETs is investigated using the measured data from the test structure. The DC characteristics of multi-finger MOSFET, such as the threshold voltage, saturation current, saturation voltage and unit-finger current are analyzed according to the finger length and the number of fingers. The analysis results show which design factor can impact on the DC characteristics of multi-finger MOSFET and provide the more accurate prediction for the operation of multi-finger MOSFET.

심음 향상을 위한 단일채널 적응 잡음 제거기

이철현(Chulhyun Lee),김필운(Pil Un Kim),이윤정(Yun Jung Lee),장용민(Yongmin Chang),배건성(Keun-Sung Bae),조진호(Jin Ho Cho),김명남(Myoung Nam Kim) 한국멀티미디어학회 2010 멀티미디어학회논문지 Vol.13 No.7

A case of Woringer-Kolopp disease on the hand

( Haryeong Ryu ),( Jeongsoo Kim ),( Chulhyun Yun ),( Jihoon Kim ),( Hyunchul Kim ),( Jongrok Lee ),( Jooyoung Roh ),( Jinok Baek ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Woringer-Kolopp disease is a rare variant of mycosis fungoides and it is also known as localized pagetoid reticulosis. It is slowly presented as a solitary, localized hyperkeratotic patch or a plaque on the extremities follows a benign course. Effective treatments for Woringer-Kolopp disease include skin-directed therapies such as topical nitrogen mustard, high-potency topical steroids, and phototherapy that may include PUVA, narrow-band UVB, or both. For small and localized lesions, surgical excision may be pursued. A 39-year-old man had presented with a 3-month history of an asymptomatic plaque on his hand. Physical examination showed a solitary round, erythematous, scaly plaque, 10 mm in size, with a slightly raised edge, on the dorsum of his left hand. A skin biopsy showed numerous atypical lymphocytes had infiltrated into the upper dermis and expanded into the epidermis with a pagetoid pattern. These pagetoid atypical cells were strongly positive for CD3, CD8, T-cell intracellular antigen-1, and they were negative for CD20, CD30 and CD56. Some reactive lymphoid cells in the dermis were positive for CD4. Further general examination revealed no evidence of systemic involvement. He was treated with surgical excision, and there has been no recurrence during the last 9 months of follow-up period. Herein, we report a rare case of Woringer-Kolopp disease.

Severe cutaneous adverse effects in patients after Influenza vaccination

( Haryeong Ryu ),( Jeongsoo Kim ),( Chulhyun Yun ),( Jihoon Kim ),( Jinok Baek ),( Jooyoung Roh ),( Jongrok Lee ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Influenza vaccines are the primary method for controlling influenza and its complication. In Korea, annual influenza immunization for all children 6 months through 59 months of age and children who are at increased risk of severe complications from influenza viral infection is included in the national immunization program. Severe side effects of influenza vaccination are rare. Mild adverse reactions of influenza vaccination are relatively frequent, such as erythema, pains, fevers, myalgia, headaches and so on. We report rare cases of severe cutaneous adverse effect in two patients after influenza vaccination. The first case is Stevens-Johnson syndrome in a 3-year-old boy which developed 4 days after influenza vaccination. Physical examination showed erythematous scaly patches on his whole body, bilateral conjunctiva injection and superficial erosion with crust on lips. He had been egg allergy. His serum was determined to be high levels of white egg specific allergen. The patient was treated with systemic steroid, topical steroid and antihistamine for 2 weeks, the lesions were improved. The second case is generalized exanthematous eruption in a 4-year-old boy which developed 6 days after influenza vaccination. Confluent erythematous maculopapules were located on his whole body. The patient was treated with systemic steroid and antihistamine for 1 week, the lesions were improved.

A case of pachydermodactyly

( Haryeong Ryu ),( Seulki Lee ),( Jeongsoo Kim ),( Chulhyun Yun ),( Jooyoung Roh ),( Jongrok Lee ),( Jinok Baek ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.1

Pachydermodactyly (PDD) is a rare, distinct form of digital fibromatosis characterized by acquired, asymptomatic swellings on the back and side of the proximal phalanges or proximal interphalangeal joint areas of the fingers. In case of patients with repetitive hand movements, appreciable improvement has been observed after cessation of the traumatic activity. Intralesional triamcinolone injections and localized surgical resection also have resulted in reduction of soft tissue swelling. A 18-year-old male gave a three year history of progressive swelling of fingers affecting predominantly the proximal interphalangeal joints of the index, middle, 4th, 5th fingers of both hands. The swelling was along the lateral aspects of the joints. There was no history of trauma or pain, and he had a full range of movement. Clinical examination was otherwise unremarkable. He also denied repetitive hand-rubbing movements. There was no family history of the disorder. X-ray of the hands showed soft tissue swelling only, no bony abnormality. Histopathologic examination showed epidermal hyperplasia with acanthosis and hyperkeratosis. Collagen fibers in the reticular dermis are thickened and haphazardly arranged, and increased deposits of connective tissue mucin. Misdiagnosis of the periarticular abnormalities as polyarticular juvenile idiopathic arthritis may lead to needless investigations and inappropriate treatment. Herein, we report a rare case of PDD

Comparison of protein quantification methods for different biopharmaceuticals

Da Hee Kang,Song Yeol Yun,Hye-Ryeon Heo,Chulhyun Lee,Seung-Rel Ryu 한국분석과학회 2023 학술대회논문집 Vol.2023 No.5

A case of pediatric hidradenitis suppurativa in girl

( Haryeong Ryu ),( Seulki Lee ),( Jeongsoo Kim ),( Chulhyun Yun ),( Jooyoung Roh ),( Jinok Baek ),( Jongrok Lee ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.1

Hidradenitis suppurativa is a chronic, recurrent inflammatory disorder of the hair follicles that affects apocrine gland bearing sites, such as the axillae and inguinal and perianal areas. Hidradenitis suppurativa is uncommon in children, with onset generally occurring well after puberty, typically between 20 and 24 years of age. We present an 8-year-old girl whose lesions commenced at the age of 6 years as painful nodules in the buttock. There was no family history of hidradenitis suppurativa or severe acne. Examination revealed few erythematous papules, nodules, and atrophic scars in the buttock. Axillary lesion was absent. She had not attained menarche and the breasts and pubic hair were Tanner stage 1. No evidence of androgen excess was noted on physical examination. A skin biopsy showed superficial dermal perivascular lymphocytic infiltration and presence of acute inflammation of apocrine glands. After the exclusion of bacterial and mycotic infections, a diagnosis of hidradenitis suppurativa was made based on the characteristic clinical presentation and the skin biopsy result. The patient had previously been treated with oral and topical antibiotics for intermittent periods with no improvement. She was treated oral roxithromycin (2.5 mg/kg/day) which marked improvement was noted after 4 weeks, and 2 months later she was in complete remission. Herein, we report a rare case of hidradenitis suppurativa in pediatric.