A case of acquired dermal melanocytosis on the face and extremities

( Chong Won Choi ),( Bo Ri Kim ),( Kwang Hyun Cho ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Dermal melanocytosis includes various kinds of congenital and acquired hyperpigmentation, which is characterized by a presence of intradermal dendritic, pigmented melanocytes. Among the congenital dermal melanocytosis, Mongolian spots, nevi of Ota, and nevi of Ito are usually present at birth or appear in early childhood. However, there are several types of acquired dermal melanocytosis that usually appear during adult life. Acquired dermal melanocysosis usually appears in Asian women. A 22-year-old woman presented with asymptomatic, multiple, symmetric, brown colored macules on the nasal ala, both dorsums of hands and feet which had been for more than 10 years. A skin biopsy from her dorsum of foot showed some pigmented dendritic cells in superficial dermis. Immunostaining for Mart-1 revealed positivity for the pigmented dendritic cells. Based on the clinical and histopathological findings, she was diagnosed with acquired dermal melanocytosis on the face and extremities.

Conformational Transition of Poly(γ-benzyl-L-glutamate)-Poly(ethylene glycol) Block Copolymers in Bulk

Choi, Young-Wook,Park, Young-Mi,Choo, Jae-Bum,Cho, Chong-Su,Sohn, Dae-Won Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.5

The bulk properties of poly(γ-benzyl-L-glutamate)-poly(ethylene glycol), PBLG-PEO, diblock copolymer were investigated. The helical transition from 7/2 to 13/5 for pure PBLG was at 120 oC while those of GE-1 and GE-2, which contain flexible PEO block 40 wt% and 60 wt% respectively, were shown at 135℃ on DSC experiments. FT-IR and XRD experiments were shown that the diblock copolymers maintained their α-helical structure in the temperature range between 25℃ and 175℃. Increasing relative size of coil part resulted in the increase of intermolecular packing distances. Due to well-maintained helical structure, lyotropic LC phases were observed for the PBLG-PEO block copolymer by the polarized optical microscope (POM). Especially, GE-3 copolymer, which has 12.5 wt% PEO contents, showed the smectic C phase. The competition of favorable aggregation energy between rod-rod and coil-coil, and unfavorable aggregation energy of rod-coil give rise to change the supramolecular structure in mixed solvent.

Bilirubin nanoparticles alleviates inflammation and angiogenesis in rosacea mouse model: Nanomedicine for rosacea therapy

( Chong Won Choi ),( Hyeongseop Keum ),( Seoyun Yang ),( Jee Woo Kim ),( Bo Ri Kim ),( Sang Woong Youn ),( Sangyong Jon ) 대한피부과학회 2021 대한피부과학회 학술발표대회집 Vol.73 No.1

Comparison of Inodilator Effect of Higenamine, YS49, YS51, Tetrahydroisoquinoline Analogs, and Dobutamine in the Rat

Won-Seog Chong,Young-Soo Lee,Young-Jin Kang,Duck-Hyung Lee,Jae-Chun Ryu,Hye Sook Yun-Choi,Ki-Churl Chang 대한생리학회-대한약리학회 1998 The Korean Journal of Physiology & Pharmacology Vol.2 No.3

<P> Tetrahydroisoquinoline (THI) alkaloids can be considered as cyclized derivatives of simple phenylethylamines. Many of them, especially with 6,7-disubstitution, demonstrate a relatively high affinity for catecholamines. Present study examines the pharmacological action of limited series of THI, using rats isolated atria and aorta. In addition, a [<SUP>3</SUP>H] prazosin displacement binding study with THI compounds was performed, using rat brain homogenates to investigate whether these probes have ㄁-adrenoceptor affinity. We also compared the vascular relaxation potency of these probes with dobutamine. YS 49, YS 51, higenamine and dobutamine, concentration-dependently, relaxed endothelium-denuded rat thoracic aorta precontracted with phenylephrine (PE, 0.1 ㄍM) in which pEC<SUB>50</SUB> were 5.56⁑0.32 and 5.55⁑0.21, 5.99⁑1.16 and 5.57⁑0.34, respectively. These probes except higenamine also relaxed KCl (65.4 mM)-contracted aorta. In isolated rat atria, all THIs and dobutamine increased heart rate and contractile force. In the presence of propranolol, the concentration response curves of YS 49 and YS 51 shifted to the right and resulted in pA<SUB>2</SUB> values of 8.07⁑0.84 and 7.93⁑0.11, respectively. The slope of each compound was not deviated from unity, indicating that these chemicals are highly competitive at the cardiac ㄂-adrenoceptors. YS 49, YS 51, and higenamine showed ㄁-adrenoceptor affinity in rat brain, in which the dissociation constant (K<SUB>i</SUB>) was 2.75, 2.81, and 1.02 ㄍM, respectively. It is concluded, therefore, that THI alkaloids have weak affinity to ㄁<SUB>1</SUB>-adrenoceptors in rat aorta and brain, respectively, while these probes show relatively high affinity for cardiac ㄂-adrenoceptors. Thus, these chemicals may be useful in the treatment of congestive heart failure.

Comparative genomic hybridization analysis of fetal chromosomal aberrations

Choi, Soo-Kyung,Kim, Young-Mi,Park, So-Yeon,Kim, Jin-Woo,Ryu, Hyun-Mee,Go, Chang-Won,Park, Chong-Tak,Jun, Jung-Young,Park, In-Suh Korean Society of Medical Genetics 1998 대한의학유전학회지 Vol.2 No.2

Comparative genomic hybridization (CGH) can now be applied to detect the origin of extra or missing chromosomal material in cases with common unbalanced aberrations and in prenatal investigations. This method has been used in 13 cases of fetal samples for this study; 3 for amniocytes, 2 for cord blood and 8 for abortus tissues. These samples were previously subjected to GTG-banding. Our study showed aneuploidy in 8 cases, and partial monosomy, partial trisomy or marker chromosome in the remaining 5. The CGH disclosed further small genetic imbalances in 4 of all 13 cases: a prenatal sample showing del(20)(q13) by GTG confirmed a loss of the segment 20p13-pter by CGH; a marker chromosome manifested normal CGH profile; chromosome der(?)(?;15) found in an abortus sample by GTG turned out to be a loss of 15pter-q14 (partial monosomy) and a gain of 10pter-q22 (partial trisomy); the der(15) shown by GTG represented partial trisomy of 3q24-qter. These findings show that CGH is very useful and efficient for cytogenetic investigations of clinical cases.

The Advantage of Cyclosporine A and Methotrexate Rotational Therapy in Long-Term Systemic Treatment for Chronic Plaque Psoriasis in a Real World Practice

( Chong Won Choi ),( Bo Ri Kim ),( Jungyoon Ohn ),( Sang Woong Youn ) 대한피부과학회 2017 Annals of Dermatology Vol.29 No.1

Background: Psoriasis is a chronic inflammatory disease. In the treatment of psoriasis, cyclosporine is commonly prescribed systemic agents. However, long-term use of cyclosporine is not recommended because of side effects such as nephrotoxicity or hypertension. Objective: To ascertain the improved safety of rotational therapy using cyclosporine and methotrexate, we investigated the frequency of abnormal results in laboratory test after long term rotational therapy using cyclosporine and methotrexate. Methods: From January 2009 to June 2014, patients who were treated with cyclosporine or methotrexate were enrolled. The clinical data and usage of medications were reviewed. Laboratory tests were conducted before starting the treatment and regularly follow- up. The occurrences of any laboratory abnormalities during the treatments were investigated. Results: A total of 21 psoriatic patients were enrolled. The mean of medication period and cumulative dose of cyclosporine and methotrexate were 497.81±512.06 days and 115.68±184.34 g in cyclosporine and 264.19±264.71 days and 448.71±448.63 mg in methotrexate. Laboratory abnormalities were found in total two patients after rotational therapy: two patients (9.5%) in aspartate aminotransferase/alanine aminotransferase and one patient (4.8%) in uric acid. No laboratory abnormalities were found in renal function test. Conclusion: We found that the rotational approaches using cyclosporine and methotrexate reduced the possibility of the development of nephrotoxicity. In addition to other advantage such as quick switching from one agent to another, the rotational therapy using cyclosporine and methotrexate can minimize the adverse events during the systemic treatment of chronic plaque psoriasis. (Ann Dermatol 29(1) 55∼60, 2017)

Both Educational Lectures and Reference Photographs Are Necessary to Improve the Accuracy and Reliability of Psoriasis Area and Severity Index (PASI) Assessment: Results from Korean Nation-Wide PASI Educational Workshop

( Chong Won Choi ),( Bo Ri Kim ),( Jong Seo Park ),( Sang Woong Youn ) 대한피부과학회 2018 Annals of Dermatology Vol.30 No.3

Background: Accurate assessment of the severity of psoriasis is important in daily practice and clinical studies. However, the assessment of psoriasis area and severity index (PASI) reflects the physician’s experience, and thus evaluations by physicians are inherently subjective, with intra-rater and inter- rater variability. Objective: To elucidate the effectiveness of PASI educational lectures and the use of reference photographs on the improvement of accuracy and reliability in PASI assessments and to develop effective educational programs for PASI assessments. Methods: We performed a before- and-after comparison study during nation-wide PASI educational workshops. The participants were asked to assess the severity components of PASI (erythema, thickness, scale, and affected area) three times: in the test administered before an educational lecture, the test immediately after the lecture, and lastly the test with the use of reference photographs. The improvement of accuracy and reliability was analyzed by comparing the results of three tests. Results: Ninety-six board-certified dermatologists and residents participated and 72 participants completed all three tests. The accuracy and reliability of the assessment of severity components of PASI increased significantly after the educational lecture and the use of reference photographs. Use of reference photographs resulted in limited improvements when the recognition of three-dimensional structures was required, such as in the assessment of thickness or scale. Conclusion: Our study confirmed that the combination of standardized educational training and reference photographs can improve the accuracy and reliability of PASI assessments. Understanding how to evaluate three-dimensional psoriatic lesions can help with proper assessment of the severity of psoriasis. (Ann Dermatol 30(3) 284∼289, 2018)

Economic Burden Can Be the Major Determining Factor Resulting in Short-Term Intermittent and Repetitive Ustekinumab Treatment for Moderate-to-Severe Psoriasis

( Chong Won Choi ),( Ji Young Choi ),( Bo Ri Kim ),( Sang Woong Youn ) 대한피부과학회 2018 Annals of Dermatology Vol.30 No.2

Background: The continuous use of biologic agents in the treatment of psoriasis has been reported to result in successful and sustained therapeutic effects and safety. However, some patients choose intermittent and repetitive treatment. Objective: To determine the factors for selecting intermittent and repetitive ustekinumab treatment for the management of psoriasis. Methods: From January 2011 to October 2016, we enrolled 30 psoriasis patients who discontinued ustekinumab treatment and were followed up for psoriasis treatment. We reviewed data regarding patients’ clinical characteristics and the treatment they received, and investigated the factors for selecting intermittent treatment. Results: A total of 52 ustekinumab treatment periods were administered to the 30 patients. Of the 52 treatment periods, 34.6% were covered by insurance and 82.4% were discontinued after sufficient improvement had been made or at the patient’s request. Further analysis comparing the first and second ustekinumab treatments revealed that the patients who used ustekinumab in second treatment were more likely to be insured. In addition, the rate of patients reaching psoriasis area and severity index (PASI)75 and PASI90 was similar between the first and subsequent ustekinumab treatments. Conclusion: We found that the patients who used ustekinumab intermittently were those who were satisfied with the outcome of ustekinumab treatment but could not afford the treatment. These results suggested that economic burden can be a factor for the patients’ choice of short-term intermittent treatment. The expansion of insurance coverage can increase the effectiveness of, and patients’ satisfaction with, the management of psoriasis. (Ann Dermatol 30(2) 179∼185, 2018)

Studies on the Differentiation of Skeletal Muscle Cells in vitro : Protein Kinase C in the Differentiation of Skeletal Muscle Cells 근세포 분화에 있어서 Protein Kinase C

Choi, Won Chul,Kim, Han Do,Kim, Chong Rak 부산대학교 기초과학연구소 1992 부산대학교 기초과학연구소 연구논문집 Vol.12 No.-

TPA나 PDGF를 처리로 인한 Protein Kinase C의 신호절단은 인산화에 의해 일어난다. 그렇지만, PKC에 의해 인산화 되어지는 targeting protein은 TPA나 PDGF 처리시에는 분자량이 서로 다른 단백질들이 인산화가 되어졌다. TPA 처리한 myoblast에서 분자량 20,000의 단백질이 인산화되었다. PDGF 처리한 세포에서는 분자량 40,000의 단백질이 인산화된 반면에 TPA와 PDGF 가 신호전달계의 활성에 있어서 다를 뿐만 아니라 그들은 장시가의 처리 동안에 PKC의 down regulation에 관계되어 짐을 암시한다. 그러나 PDGF는 TPA의 경우에서 보다 빠른 down regulation을 유도하였다. 면역세포화학적인 연구에서 PKC의 동위효소인 PKC Ⅱ는 세포질에, PKC Ⅲ는 세포질과 인에 각각 분포하고 있었다. Myoblast에 있어서 PKC의 두가지 형태의 동위효소의 발현은 이들 동위효소들이 signal transduction이나 down regulation의 각기 다른 경로에 개입되어 진다는 것을 암시한다. Treating 12-0-tetradecanoylphorbol 13-acetate(TPA) or platelet-derived growth factor(PDGF), the signal transduction of protein kinase C(PKC) is occurred by the phosphorylation. However the targeting proteins phosphorylated by PKC were found to be different proteins in molecula weights when TPA or PDGF was treated to the myoblast. In the TPA-treated myoblast cells, te protein of Mr. 20Kd was phosphorylated. In the PDGF-treated cells, the protein of Mr.40 Kd was phosphorylated, while the protein of Mr.20 Kd which phosphorylated in the TPA-treatment was dephosphorylated. These results indicate that not only TPA and PDGF are different in activating the signal transduction pathways, but also they may involve in the down regulation of PKC during the long-term treatment. But PDGF gave rise more rapidly down regulation than in the case of TPA. Using immunocytochemical approach, two distinct PKC isozymes, PKC Ⅱ and PKC Ⅲ, have been localized in cytoplasm and both cytoplasm and nucleolus, respectively. Therefore, the expression of two types of PKC in the myoblast suggest that the isozymes of PKC may involve in each different pathway of signal transduction or down-regulation.

Anisotropic twinning and slip behaviors and their relative activities in rolled alpha-phase titanium

Won, Jong Woo,Choi, Seong-Woo,Yeom, Jong-Taek,Hyun, Young-Taek,Lee, Chong Soo,Park, Sung Hyuk Elsevier Sequoia 2017 Materials science & engineering Structural materia Vol.698 No.-

<P><B>Abstract</B></P> <P>Loading-direction-dependent anisotropic behaviors of twinning and dislocation slip of rolled alpha-phase titanium (<I>α</I>-Ti) were investigated via uniaxial compression tests performed along three orthogonal directions (the rolling direction (RD), transverse direction (TD), and normal direction (ND)). The initial texture with basal poles inclined at ~30° from the ND toward the TD caused the angle relationship between the <I>c</I>-axis and the loading axis, which governed the Schmid factor (SF) for twinning and slip systems, to differ with the applied loading direction. Analyses of the SF and Taylor axis along with electron backscatter diffraction measurements revealed the dominant deformation mechanisms to be {10-12} twinning and prismatic slip under compression along the RD and TD and {11-22} twinning and basal slip under compression along the ND. Calculation of twinning strain and analysis of the in-grain lattice rotation angle revealed that the relative contribution of twinning to deformation increased in the order of ND>RD>TD, but that of prismatic slip decreased in the order of ND<RD<TD. These results demonstrate that activations of twinning and slip systems and their relative activities vary significantly with the applied deformation direction owing to the preferred crystallographic orientation of the initial material.</P>