Low-Cost, Low-Power, High-Capacity 3R OEO-Type Reach Extender for a Long-Reach TDMA-PON

Kwangok Kim,JieHyun Lee,Sang Soo Lee,Jong-Hyun Lee,장윤선 한국전자통신연구원 2012 ETRI Journal Vol.34 No.3

This paper proposes a low-cost, low-power, and highcapacity optical-electrical-optical-type reach extender that can provide 3R frame regeneration and remote management to increase the reach and split ratio with no change to a legacy time division multiple access passive optical network. To provide remote management, the extender gathers information regarding optical transceivers and link status per port and then transmits to a service provider using a simple network management protocol agent. The extender can also apply to an Ethernet passive optical network (E-PON) or a gigabit-capable PON (G-PON) by remote control. In a G-PON, in particular, it can provide burst mode signal retiming and burst-to-continuous mode conversion at the upstream path through a G-PON transmission convergence frame adaptor. Our proposed reach extender is based on the quad-port architecture for cost-effective design and can accommodate both the physical reach of 60 km and the 512 split ratios in a G-PON and the physical reach of 80 km and the 256 split ratios in an E-PON.

The Antimicrobial Activity of (-)-Epigallocatehin-3-Gallate and Green Tea Extracts against Pseudomonas aeruginosa and Escherichia coli Isolated from Skin Wounds

( Jiehyun Jeon ),( Joo Ha Kim ),( Chang Kyu Lee ),( Chil Hwan Oh ),( Hae Jun Song ) 대한피부과학회 2014 Annals of Dermatology Vol.26 No.5

Background: Skin infections with Gram-negative bacteria are sometimes challenging to treat, because these bacteriashow multidrug resistance against commonly used antibiotics and patients with Gram-negative bacterial infection overall have deteriorated in conditions in many cases. Studies have shown that epigallocatechin gallate (EGCG) and green tea extracts (GTE) inhibit the growth of several Gram-positive bacteria species. Objective: The purpose of this study was to investigate the minimum inhibitory concentrations (MICs) of EGCG and GTE in Pseudomonas aeruginosa and Escherichia coli, and assess the use of these chemicals as an alternative or adjunct topical antimicrobial agent against P. aeruginosa and E. coli with multidrug resistance. Methods: The MICs of EGCG, GTE, and other tested antibiotics were measured and compared to determine the antibacterial efficacy and the differences in pattern of resistance. Results: The P. aeruginosa and E. coli strains used in this study showed multidrug resistance. EGCG inhibited the growth of P. aeruginosa at a MIC level of 200∼400 μg/ml. The MIC of GTE was a 1 : 16 dilution for P. aeruginosa. EGCG showed antimicrobial activity against E. coli at a MIC of 400 μg/ml. In the case of GTE, the MIC was a dilution between 1:8 and 1:4 for E. coli. Conclusion: EGCG and GTE showed potential as alternative or adjunct topical antimicrobial agents for infections that are resistant to traditional antibiotic therapy. (Ann Dermatol 26(5) 564∼569, 2014)

레이저 치료 후 발생한 부작용 69예에 대한 고찰

전지현 ( Jiehyun Jeon ),이정우 ( Jung Woo Lee ),윤석권 ( Seok Kweon Yun ),양준모 ( Jun Mo Yang ),고현창 ( Hyun Chang Ko ),김일환 ( Il Hwan Kim ),노영석 ( Young Suck Ro ),박미연 ( Mi Youn Park ),박영립 ( Young Lip Park ),박천욱 ( C 대한피부과학회 2016 대한피부과학회지 Vol.54 No.5

Background: During the past two decades, laser treatments have been increasingly performed by various personnel in Korea. However, as a result, adverse events related to laser treatments have also increased. Objective: This study aimed to characterize cutaneous adverse events associated with laser treatments in Korea and to consider feasible ways to minimize possible laser-associated adverse events. Methods: Adverse event reports after laser treatments were collected from the members of the Korean Dermatological Association. A retrospective analysis of clinical data was performed regarding the pre-treatment lesion, specific laser type applied, personnel who performed the procedure, and consequences in terms of treatmentrelated complications. Results: A total of 69 reported cases of adverse events associated with laser treatment were collected. The most frequently reported adverse event was postinflammatory dyspigmentation, followed by secondarily induced dermatological disease, treatment-inflicted burn, and residual scar. Conclusion: Both expected and unexpected adverse events occur after laser treatments. Most adverse events are not serious, but proper dermatological attention should be given to avoid complications. It should be noted that the safest and the most successful laser treatment can be provided only by qualified personnel. (Korean J Dermatol 2016;54(5):362∼367)

A case of paronychia caused by Citrobacter koseri

( Jung Woo Lee ),( Jiehyun Jeon ),( Hae Jun Song ),( Chil Hwan Oh ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Paronychia usually is caused by infection and bacteria are the most common causative organisms. It generally presents as redness, tenderness and swelling with occasional oozing of nail fold of digits. This may be commonly caused by Staphylococcus aureus, and other bacterial causes of paronychia in the current study included Streptococcus pyogenes and Psudomonas aeruginosa. A 57-year-old male was seen for pain on subungal area of his right 5th toe lasted for 4-5 years. The patient was diagnosed nasopharyngeal cancer with neck metastasis in 2001 and underwent numerous sessions of chemotherapy and radiotherapy. Clinical examination revealed tender erosive patches with oozing. The toenail was extracted and bacterial swab culture was done on the lesion. Gram’s stain and culture result showed Citrobacter koseri. The patient was treated with cephalexin, which was shown to be susceptible, for several weeks and wound was improved. Citrobacter species are motile, facultative, and anaerobic gram-negative enteric bacilli found in the intestinal tract. The genus consists of three different species, one of which, Citrobacter koseri is known cause of devastating meningitis. Antimicrobial therapy is based on the sensitivity of the pathogen microorganism. Subungal involvement of Citrobacter koseri has not yet been reported on our knowledge. Thus we report a case of paronychia caused by Citrobacter koseri infection in an immunocompetent individual.

Lymphocele after Lipoma Removal in Inner Thigh

( Jung Woo Lee ),( Jae Woo Ahn ),( Geo Han ),( Seung Hwi Kwon ),( Jiehyun Jeon ),( Soo Hong Seo ) 대한피부과학회 2017 Annals of Dermatology Vol.29 No.1

Multiple pyogenic granulomas over previous treated area in a postmenopausal woman on hormone replacement therapy

( Jung Woo Lee ),( Geo Han ),( Hae Jun Song ),( Chil Hwan Oh ),( Jiehyun Jeon ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.1

Pyogenic granuloma is a benign vascular tumor that is common in children but may occur at any age. Although the lesion usually presents as a solitary papule, the development of multiple satellite pyogenic granulomas has been rarely reported. A 53-year-old woman presented with easily bleeding sessile papule and surrounding reddish papules on scalp lasted for a year. The primary lesion had been treated by electrodessication 1.5 years ago but the lesion has been recurred with new multiple satellites. She was treated with hormone replacement therapy to improve menopausal symptoms for 3 years. The histological findings of the primary and satellite lesions showed many dilated capillaries and epidermal collarette which are consistent with pyogenic granuloma. Two consecutive excisions for remnants were done and all the specimens confirmed the diagnosis of pyogenic granuloma. Multiple pyogenic granulomas are known to develop around the recently treated areas and one of hypotheses proposes releasing of various endogenous substances including angiogenic factors by trauma. Furthermore, frequent development of pyogenic granuloma during pregnancy implies the hormonal factors as a major role. Therefore, postmenopausal women treated with hormonal therapy may be at increased risk for pyogenic granuloma. We report herein a rare case of multiple pyogenic granulomas over previous treated area, in a postmenopausal woman on hormone replacement therapy.

A case of cutis marmorata telangiectatica congenita

( Jung Woo Lee ),( Geo Han ),( Hae Jun Song ),( Chil Hwan Oh ),( Jiehyun Jeon ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Cutis marmorata telangiectatica congenita(CMTC) is rare, sporadic, congenital lymphovascular malformation. The cutaneous manifestations are characterized by the presence of a purplish, reticulated, vascular network with a segmental distribution, commonly involving the lower limbs and trunk. A male newborn vaginally delivered at full-term without any fetal distress had congenital purpuric bluish reticulated maculopatches on his right leg. With his cutaneous manifestation, the diagnosis of CMTC was suspected. Serial orthopedic measurements showed no sign of limb length discrepancy. However, sonographic findings of brain and abdomen revealed grade 1 germinal matrix hemorrhage in brain and mild hydronephrosis in left kidney. In addition, audiologic screening showed slight hearing abnormality at right ear. Cutaneous lesion improved after 7 weeks of follow up with no further extracutaneous symptom appeared. Differential diagnosis of CMTC is mainly from cutis marmorata, which is not persistent and regarded as a physiological phenomenon. Numerous extracutaneous, systemic anomalies can be present in CMTC patient. The most common association is limb asymmetry and other vascular anomalies or neurologic, skeletal defects should also be regarded. CMTC itself has a good prognosis gradually improving within first 2 years of life. Therefore, understanding of benign nature and emphasizing the need for periodic follow up in the case of CMTC is important.

A case of concomitant psoriasis and atopic dermatitis treated with ustekinumab

( Jung Woo Lee ),( Jiehyun Jeon ),( Chil Hwan Oh ),( Hae Jun Song ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

In its pathogenesis, psoriasis has been considered as Th1 and Th17 immune response while Th2 response is dominant in atopic dermatitis(AD). Therefore, they were expected to be mutually exclusive. But it was also known that Th1, Th17, and Th22 cells were also involved in AD. Recently there were emerging reports of managing AD with ustekinumab, a monoclonal antibody blocking both interleukin(IL)-12 and IL-23 used to treat psoriasis. A 35-year-old man was presented with over a 5-year history of psoriasis which was waxing and waning despite of 3 months of oral cyclosporine. He also had AD that was relatively well controlled. His psoriatic condition was suboptimally controlled with even over 3 months of narrow band-UVB phototherapy. Then the patient received treatment of ustekinumab administered in a single dose of 45 mg at weeks 0, 4, and 12. One month after the second injection, most of his psoriatic lesions showed improvement, but his AD symptom was flared up, especially on the face. While using topical corticosteroids and antihistamines for AD, ustekinumab therapy was continued further. After third administration of ustekinumab, AD as well as psoriasis showed marked improvement. We assume that ustekinumab may work for improvement of AD by preventing the upregulation of Th17 cells in our case as previous reports of AD treated with ustekinumab. We hereby report a rare case of concurrent psoriasis and AD treated with ustekinumab.

Need for applying high index of suspicion in daily practice: four cases of tinea incognito

( Cjung Woo Lee ),( Jae Woo Ahn ),( Jiehyun Jeon ),( Chil Hwan Oh ),( Hae Jun Song ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Tinea incognito is dermatophyte infection of the skin with an atypical appearance. In many cases, there are previous treatments-tend to be improper-with immunosuppressive agents such as steroids or calcineurin inhibitors. As the fungus-induced local inflammation is suppressed, it may show a modification of typical manifestations, presenting various morphologies. Patient 1 was a 66-year-old man presenting erythematous macules, papules with scanty scales on face and neck. He had applied topical steroids for previous 4 months. Patient 2, 37-year-old man visited for mild tender, itchy erythematous bullous oozing patches on left great toe area about a year ago. The lesion was thought to be kind of contact dermatitis with secondary infection. Despite of continuous treatment, the lesion kept worsening. Patient 3 was a 39-year-old woman with underlying psoriasis. Her psoriasis was generally stable but scaly erythematous patch on left post-auricle was the only lesion goes worsening. Patient 4, 23-year-old man with atopic dermatitis presented for uncontrolled itchy xerotic patches on whole body. All of above cases revealed positive findings on serial KOH test and were successfully treated by antifungal therapies. The entity of tinea incognito can mimic many other cutaneous disorders. Whenever patients complain about atypical skin lesions unresponsive to immunosuppressive agents, it is important Tinea incognito is dermatophyte infection of the skin with an atypical appearance. In many cases, there are previous treatments-tend to be improper-with immunosuppressive agents such as steroids or calcineurin inhibitors. As the fungus-induced local inflammation is suppressed, it may show a modification of typical manifestations, presenting various morphologies. Patient 1 was a 66-year-old man presenting erythematous macules, papules with scanty scales on face and neck. He had applied topical steroids for previous 4 months. Patient 2, 37-year-old man visited for mild tender, itchy erythematous bullous oozing patches on left great toe area about a year ago. The lesion was thought to be kind of contact dermatitis with secondary infection. Despite of continuous treatment, the lesion kept worsening. Patient 3 was a 39-year-old woman with underlying psoriasis. Her psoriasis was generally stable but scaly erythematous patch on left post-auricle was the only lesion goes worsening. Patient 4, 23-year-old man with atopic dermatitis presented for uncontrolled itchy xerotic patches on whole body. All of above cases revealed positive findings on serial KOH test and were successfully treated by antifungal therapies. The entity of tinea incognito can mimic many other cutaneous disorders. Whenever patients complain about atypical skin lesions unresponsive to immunosuppressive agents, it is important

Pseudoaneurysm as a Post-Biopsy Complication

( Geo Han ),( Jung Woo Lee ),( Seung Hwi Kwon ),( Jiehyun Jeon ),( Hae Jun Song ),( Chil Hwan Oh ),( Sang Il Suh ),( Soo Hong Seo ) 대한피부과학회 2016 Annals of Dermatology Vol.28 No.6