한국인에 있어 유전성안드로겐 탈모증의 유병율과 임상 유형

유재학(Jae Hak Yoo),은희철(Hee Chul Eun),김계정(Kea Jeung Kim),문상은(Sang Eun Moon) 대한피부과학회 1995 대한피부과학회지 Vol.33 No.1

Background : Androgenetic alopecia is a common problem, affecting approximately 50 percent of men and perhaps many women, over the age of 40 in Caucasians. There have been several reports about the prevalence and types of androgenet clopecia in the general population of Caucasians however the prevalence and types of and renetic alopecia has not been reported in the general population of Korea. Objective : Our purpose was to ascertain the prevalence ar d ypes of androgenetic alopecia in Koreans and to compare it with that of the Caueasian. Methods : A survey on the prevalence and clinical types of aidrogenetic alopecia was conducted by one dermatologet from July to September, 1993. The total number of subjects was 1224 males and 1094 femaly., Results : The following esults were obtained from this sudy l. In men, the prevalence rate of androgenetic alopecia increased steadily with advancing age and the prevalence rate of more advanced degrees of alepcia(types V, VI and VII) remained relatively low until the seventh decade of life. The preralence rates until the age of sixties in Korean men were lower than that of the white and is pattern became closer with that of the white after the seventies. 2. In Korean women, the prevalence rate of androgenetic was lower than that of the white until fifties and it increased markedly after sixties. Conclusion : The prevalence rate of androgenetic alopecia in Korean was lower than that of the Caucasian. Our data adicates that Korean men have a late onset of baldness and more preservation of the frontal hair line with decreased frequencyte frontoparitetal loss than the Caucasian. (Kor J Dermatol 1995; 33(1): 67-75)

배양된 인체 조갑 기질세포와 표피 각질형성세포에 미치는 수종 항진균제의 영향

유재학 ( Jae Hak Yoo ),정진호 ( Jin Ho Chung ),은희철 ( Hee Chul Eun ) 대한피부과학회 1998 大韓皮膚科學會誌 Vol.36 No.3

Background: Long-term oral itraconazole and terbinafine are widely used in the treatment of onychomycosis. Accelerated nail growth in patients with itraconazole has been described in several reports. However, there has been no report regarding the effect of antifungal agents on cultured nail matrix cells(NMCs). Objective :We applied several antifungal agents on cultured human NMCs and epidermal kera- tinocytes(EKs) to compare the cytotoxicity of several antifungal agents and also to verify possible stimulating effects of itraconazole and 6-hydroxyitraconazole on nail growth. Methods : To evaluate the effect of antifungal agents, the 3-(4,5-dimethylthiazo1-2-yl) 2,5-diphenyl- tetrazolium bromide(MTT) test, tritiated thymidine incorporation test, and lactic dehydrogenase(LDH) leakage test were used. Results: Dose dependent decreases in cell viability and DNA synthesis, and dose dependent increases in LDH liberation were observed in cultured human NMCs and EKs after exposure to several antifungal agents. The dose-response reaction patterns for NMCs and EKs to antifungal agents were similar. The cytotoxicity potency of several antifungal agents measured by each method were slightly different. Itraconazole and 6-hydroxyitraconazole did not show stimulating effects on cell proliferation in in vitro monolayer cell culture systems. Conclusion : These observations suggest that itraconazole appeared less cytotoxic but showed no stimulating effects on nail matrix cell proliferation in vitro. Cultured human EKs as well as NMCs may be useful in evaluating the effects of agents which are involved in nails. (Korean J Dermatol 1998;36(3): 415-421)

Phototrichogram 을 이용한 한국인 두피 모발 특성의 정량적 분석

유재학(Jae Hak Yoo),박형윤(Hyung Yoon Park),박태호(Tae Ho Park),김계정(Kea Jeung Kim) 대한피부과학회 2002 대한피부과학회지 Vol.40 No.9

N/A Background: Although the diagnosis of hair disease depends on the comparison of normal and abnormal findings, data on normal hair characteristics in Koreans have not been reported. We have developed some technical improvements on phototrichogram methodology to assess hair characteristics, Objective: This study was performed to quantify Koreans` hair characteristics at each site (eg, vertex, occipital, temporal) of the scalp according to the age and sex using the phototrichogram and to compare the differences of hair characteristics between Caucasian and Korean population. Methods: Hairs in the precisely defined circle at each (vertex, temporal, occipital) area of the scalp in 42 healthy volunteers (16 men and 26 women) were evaluated according to sex and age groups, respectively. Each circumscribed area of the scalp, centered with a dot tattoo to ensure reproducibility, were first shaved: The shaven area was first photographed just after shaving. Two days later, grouping pattern of grouped hair unit, total and anagen hair counts were determined from low magnification image. The linear hair growth rate (㎛/day) and hair shaft diameter were obtained from high magnification image. Results: The results can be summarized as follows: 1. The range of hair density was 119±13/㎠~137±12/㎠ in male and 92±24/㎠~139±23/㎠ in female. Hair density of the occiput was significantly higher that of temple. 2. The range of linear hair growth rate was 300±19㎛/day~319±27㎛/day in males and 289±17㎛/day~327±54㎛/day in females. Hair growth rate in each group decreased in order of vertex, occiput and temple. Most of the hairs on the vertex in older males have slower growth rate than in other groups. 3. The range of hair thickness was 70±6㎛~89±10㎛ in males and 75±7㎛~87±6㎛ in females. Hairs of the vertex in the older male group (age≥45 year-old) were thinner than those of the occiput. The population of thin hair (<40㎛) on the vertex in older males was 7.6% larger than that of other sites. 4. The range of anagen ratio was 91.0%~93.7% in males and 91.9%~94.1% in females. Conclusions: Lower hair density, larger hair diameter and slower hair growth rate were remarkable in Koreans than in Caucasian. In addition, considering the hair characteristics of Koreans, the newer, improved method of phototrichogram will be a promising tool in the study of the hair disease including androgenetic alopecia, and in the quantitative analysis of the effects of agents stimulating hair growth. (Korean J Dermatol 2002;40(9):1035~1043)

인체 각질형성세포 배양모델을 이용한 수종 용제의 독성도 측정에 관한 연구

유재학 ( Jae Hak Yoo ),은희철 ( Hee Chul Eun ),정진호 ( Jin Ho Chung ),유일재 ( Il Je Yu ) 대한피부과학회 1996 대한피부과학회지 Vol.34 No.1

Background: As in vivo models such as animal and human tests have many potential problems the keratinocyte culture model has previously been used as an in vitro model for testing skin irritancy for common skin irritants. Objective : To determine the skin irritant potency of several solvents, we employed cultured human keratinocytes as an in vitro model. Methods : To evaluate the cytotoxicity of solvents, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) test, lactic dehydrogenase(LDH) release test, and tritiated thymidine incorporation test were used. Results : Dose dependent decrease of cell viability and DNA synthesis, and dose dependent increase in leakage of LDH liberation were observed in normal cultured human keratinocytes after exposure to several solvents. The cytotoxicity potency of several solvents measured by each method were slightly different. Conclusion : These observations suggest that the cultured human keratinocyte model would be useful in evaluating the cytotoxicity of solvents. (Kor J Dermatol 1996;34(1): 58~63)

건선에서의 Calcipotriol 연고의 치료효과

유재학(Jae Hak Yoo),고우석(Woo Seok Koh),윤재일(Jai Il Youn) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.4

Background : Topical vitamine D analogues have been reported to bean effective treatment in patients with psoriasis. Calcipotriol, a new vitamin D analogue, is effect ve and at least 100 times less calcemic than calcitriol. Objective : Our purpose was to study the clinical efficacy, safety and tolerability of calcipotriol ointment in the treatment of psoriasis. Methods : Twenty five patients with chronic poriasis were treated with calcipotriol ointment(50pg/g) twice daily. Efficacy as meaaured by the clinical degree of erythcimor, scale and thickness of the lesions, and safety were assessecl every 2 weeks. Results : The total score of erythema, scale and thickness of the lesions decreased in 6 weeks from 8.52+0.76 to 3.80+1.7 with calcipotriol. Some patients developed mild and transient local side effects. The laboratory tests including serum calcium remained unchanged. Conclusion : Topical applicalion of calcipotriol ointment for 6 week was found to bean effective and safe treatment of psoriasis vulgaris. (Kor J Dermatol 1994; 32(4): 655-661)

비침습적 측정방법을 이용한 수종 용제가 자극 피부염에 미치는 영향

유재학(Jae Hak Yoo),은희철(Hee Chul Eun),서대헌(Dae Hun Suh),유일재(Il Je Yu) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.6

Background : Solvents play an immense role in the industria sector. Irritant dermatitis which is more common than allergic contact dermatitis can be caused by solvents, Objective : Our purpose was to compare the skin irritancy of several solvents using human and guinea pig skin models. Methods : The skin responses to short contact with etharol, acetone, dimethylsulfoxide (DMSO) and xylene were measured by visual scoring of erythm, transepidermal water loss and laser doppler flowmetry. Results : The results are summarized as follows . 1. Guinea pig and human skin responses to normal saline, ethanol, and acetone were nearly negligible. 2. Guinea pig skin responses to 99.9% DMSO under occlusion for 0.5 min were assessed by visual scoring system, TEWL, and LDF. They are measured 3+0.(0,1+21.70, 45+12.70 at 5 min after removal of 99.9% DMSQ, and 0.83+0.41, 10.5+3.83, 36+4.0, to 120 min after removal. 3. Guinea pig skin responses to 97% xylene under occlusion for 5 nin were assessed by visual scoring system, TEWL and LDF. They are measured 3+0.00, 1. 5.82, 77+11.7 at 5 min after removal of 97% xylene, and 1.83+0.75, 5.5+3.21, 39.17+11.53 at l2 min after removal. 4. Human skin responses to 75% DMSO under occlusion for 1 min were assessed by visual scoring system, TEWL and LDF. They are measured 2,5+0.5, 63+25.8, 51+13.7 at 5 min after removal of 75% DMSO, and 0.17+0.41, 14.67+15.87, 21.17-8. 1 at 120 min after removal. 5. Human skin responses to 97% xylene under occlusion for 12 min were assessed by visual scoring system, TEWL and LDF. They are measured 2.7+0.52+4.22, 76+14.30 at 5 min after removal of 97% xylene, and 0+0, 2.5+0.55, 3.17+0.98, 120 emOVBI. Concbsion : Short contact vrith DMSO and xylene cause visib erythema and an increase in TEWL and cutaneous blood flow. The reaction patterns in hurr an and guinea pig skin models were similar. (Kor J Dermatol 1994: 32(6): 1026-1034)

초음파를 이용한 수삼의 품질 예측

유재학 ( Jae Hak Yoo ),장규섭 ( Kyu Seob Chang ),장동일 ( Dong Il Chang ),강호양 ( Ho Yang Kang ) 한국산업식품공학회 2002 산업 식품공학 Vol.6 No.2

직업적으로 <SUP>192</SUP>Ir에 피폭되어 발생된 방사선피부염

김계정(Kea Jeung Kim),유재학(Jae Hak Yoo) 대한직업환경의학회 1998 대한직업환경의학회지 Vol.10 No.1

에너지 절약을 위한 토굴저장 통계란의 품질특성

장영일(Yeong Il Chang),유재학(Jae Hak Yoo),한성욱(Sung Wook Han),장규섭(Kyu Seob Chang) 한국산업식품공학회 2001 산업 식품공학 Vol.5 No.4

N/A N/A

성인 남녀의 가마와 앞머리선의 형태에 관한 연구

김창식 ( Chang Sik Kim ),유재학 ( Jae Hak Yoo ),박태호 ( Tae Ho Park ),김계정 ( Kea Jeung Kim ) 대한피부과학회 2005 大韓皮膚科學會誌 Vol.43 No.8