Novel Mechanism of Massive Photoreceptor Degeneration Caused by Mutation in the trp Gene of Drosophila

Yoon, Jaeseung,Ben-Ami, Hagit Cohen,Hong, Young Seok,Park, Soyeon,Strong, Lydia L.R.,Bowman, John,Geng, Chaoxian,Baek, Kwanghee,Minke, Baruch,Pak, William L. 경희대학교 생명자원과학연구원 2000 硏究論文集 Vol.21 No.-

The Drosophila trp gene encodes a light-activated Ca^(2+) channel subunit, which is a prototypical member of a novel class of channel proteins. Previously identified trp mutants are all recessive, loss-of-function mutants characterized by a transient receptor potential and the total or near-total loss of functional TRP protein. Although retinal degeneration does occur in these mutants, it is relatively mild and slow in onset. We report herein a new mutant, Trp^(p365), that does not display the transient receptor potential phenotype and is characterized by a substantial level of the TAP protein and rapid, semi-dominant degeneration of photoreceptors. We show that, in spite of its unusual phenotypes, Trp^(p365) is a trp allele because a Trp^(p365) transgene induces the mutant phenotype in a wild-type back-ground, and a wild-type trp transgene in a Trp^(p365) background suppresses the mutant phenotype. Moreover, amino acid alterations that could cause the Trp^(p365) phenotype are found in the transmembrane segment region of the mutant channel protein. Whole-cell recordings clarified the mechanism underlying the retinal degeneration by showing that the TRP channels of Trp^(p365) are constitutively active. Although several genes, when mutated, have been shown to cause retinal degeneration in Drosophila, the underlying mechanism has not been identified for any of them. The present studies provide evidence for a specific mechanism for massive degeneration of photoreceptors in Drosophila. Insofar as some human homologs of TRP are highly expressed in the brain, a similar mechanism could be a major contributor to degenerative disorders of the brain.

A case of ostraceous psoriasis with psoriatic arthritis in AIDS patient

( Minkee Park ),( Myeong Jin Park ),( Misoo Choi ),( Chan Hee Nam ),( Byung Cheol Park ),( Seung Phil Hong ),( Myung Hwa Kim ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.1

Human immunodeficiency virus infection may be presented as severe and atypical cutaneous diseases. Psoriasis also can be developed in HIV patients associated with immune dysfunction and be presented as more severe and atypical manifestation. Furthermore, treatment of psoriasis in HIV patients can be complex and challenging. A 50-year old man with a history of 9 years of HIV presented for thick scaly hyperkeratotic plaques on the distal part of extremities and face. He has stopped highly active antiretroviral therapy (HAART) for 8 years. Physical examination showed diffuse areas of greasy scaling with underlying erythema on face and scalp. Extremities showed firmly adhered thick scales resembling an oyster shell. T lymphocyte subsets of peripheral blood revealed that CD4+ T-cell count was 66cell/ul and CD4/CD8 ratio was decreased to 0.19. HIV RNA titer was 224, 701 copies/mL. Histopathologic analysis confirmed psoriasis and rheumatologist confirmed psoriatic arthritis (PsA). We diagnosed him as an ostraceous type psoriasis with PsA. Treatment was initiated with oral acitretin, oral low-dose steroid, topical calcipotriol topical corticosteroid and re-initiation of HAART therapy. Herein, we report uncommon clinical variant of psoriasis with PsA in AIDS patient and discuss about a possible pathogenesis and treatment.

Hybrid cyst with verrucous feature on scalp

( Minkee Park ),( Mi Soo Choi ),( Chan Hee Nam ),( Ji Seok Kim ),( Byung Cheol Park ),( Myunghwa Kim ),( Seung Phil Hong ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.1

Various skin appendageal cysts including epidermal cysts, trichilemmal cysts, vellus hair cysts, pilomatricoma or steatocystoma can develop from pilosebaceous unit. A Hybrid cyst is a term proposed to describe a rare cystic lesion which involves more than two components of pilosebaceous unit. So far, there are four reports of hybridcysts in Korea up to date, however, none of them showed verrucous feature on the surface. A 46-year-old male presented with 0.5 x 0.3cm sized yellowish tender subcutaneous nodule on scalp which persisted for a year. Skin biopsy was done, featuring cystic lesion with multiple components including epidermal cyst and trichilemmal cyst. Furthermore, hyperplastic epidermis showed verrucous features. It has been reported that HPV infection could be closely related to appendageal cystic lesion, particulary plantar cyst. The report told that 30.8% of cases showed parakeratosis, vacuolar structures, and eosinophilic inclusion bodies, and 38.5% of cases showed positivity in PCR for HPV. To know whether the lesion of patient in our case corresponds with hybrid cyst with secondary verrucous change, or hybrid cyst arising from preexisting verruca, further investigation is needed regarding relationship of HPV and pathogenesis of tumors from pilosebaceous unit and multipotential stem cells of hair follicles.

[P327] Multiple basal cell carcinomas around the nose

( Minkee Park ),( Gi Hyun Sung ),( Myeong Jin Park ),( Mi Soo Choi ),( Seung Phil Hong ),( Myung Hwa Kim ),( Byung Cheol Park ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.1

Basal cell carcinoma(BCC), the most common cutanenous malignancy, occurs mainly in a single but rarely multiple. Multiple BCCs may occur with genetic disease like nevoid BCC syndrome, Bazex syndrome and Rombo syndrome and with UV radiation and long-term arsenic intake. We herein report a rare case of multiple BCCs around the nose without genetic disease. A 73-year-old female presented with multiple black colored macules, patches and nodule around the nose for about 1 year. Personal medical history was unremarkable. There was no history of sunburn, familial history of BCC nor of arsenic treatment. A skin biopsy was performed in all five separate black colored lesions. Histopathologic examination revealed that all these lesions corresponded to BCCs mostly micronodular type. After diagnosis of BCC, all lesions were excised by Mohs micrographic surgery with free resection margin. Thereafter the patient remains under close follow-up. With our knowledge, this is a rare case of multiple BCCs lacking risk factors around the nose.

Expression of wound healing markers in Neurofibromatosis type 1

( Minkee Park ),( Seung Phil Hong ),( Byung Cheol Park ),( Myung Hwa Kim ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.2

Background: Neurofibromatosis type 1(NF1) is an autosomal dominant disorder, caused by heterozygous mutations of the NF1 gene. NF1 protein has been suggested to be a downregulator of the Ras-signaling pathway which increases the cell growth and proliferation in most tissues. Although the surgical treatment is major therapeutic option to remove the NF, there are few studies regarding the complex process of wound healing in the skin of NF1. Objectives: To investigate expression of wound healing markers in the skin of NF1 compared with normal skin and hypertrophic scar(HTS). Methods: Real-time PCR was performed to compare mRNA expression of 14 wound healing marker genes. Based on the real-time PCR results, immunohistochemistry was done on NF lesions comparing HTS and normal skin. Results: Of 14 genes, the mRNAs of MMP-1, MMP-9, FGF2, KGF, TNF-α and IL-6 were in NF lesions, and that of MMP-9 showed a significant increase comparing to normal tissues (p=0.021). Immunohistochemically, MMP-9 was decreased in NF tumor per se and scar area of HTS comparing with reticular dermis of normal tissue. FGF2 and TNF-α showed moderate to intense expression in epidermis and peritumoral and tumoral area of NF lesions. By contrast, the expression of TNF-α was decreased in scar area of HTS. Conclusion: NF lesions have high expression of MMP-9 mRNA, FGF2 protein and TNF-α protein. These altered level of expression in NF suggest that NF lesion could be expected almost normal healing process instead of leaving HTS.

Comparison of responses to picosecond and nanosecond lasers in the treatment of hyperpigmented skin lesions

( Minkee Park ),( Hye Young Kang ),( Mi Soo Choi ),( Jong Gu Kim ),( Byung Cheol Park ),( Myung Hwa Kim ),( Seung Phil Hong ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.2

Background: In the field of the treatment of pigmentary lesion, the picosecond 755 Кalexandrite laser has been recently introduced, hoping for a better effect on tattoo removal and pigmentation disorders. Objectives: This study compared the efficacy of the picosecond based alexandrite laser (750 Э, 755 К) with nanosecond based conventional Q-switched Nd:YAG lasers (10 Ю, 532 and/or 1064 К) lasers in the treatment of both epidermal pigmented and multi-colored dermal tattoo lesions. Methods: KIWA:A1 guinea pigs with epidermal hyperpigmentation induced by UVB irradiation were treated with each of 755 Кpicosecond laser or 532 КQs-Nd:YAG laser. 6 different color tattoos (red, orange, yellow, green, blue, and black) on the back of albino guinea pigs were treated with one session of 755 К picosecond, 1064 Кor 532 КNd:YAG laser treatment. Results: Although both picosecond and Nd:YAG lasers showed the same effect on epidermal hyperpigmentation, the Nd:YAG laser had more initial tissue reaction and latterly developed post-inflammatory hyperpigmentation. The picosecond laser was superior for removing blue and green color tattoos only, whereas it was inferior or similar for other colors. Conclusion: Picosecond laser is better than conventional Qs-Nd:YAG laser in the treatment of epidermal pigmented lesions, because of no damage to surrounding tissue. However, this device may be less effective in the treatment of color tattoo lesions.

The oral microbiome of implant-abutment screw holes compared with the peri-implant sulcus and natural supragingival plaque in healthy individuals

MinKee Son,Yuri Song,Yeuni Yu,Si Yeong Kim,Jung-Bo Huh,Eun-Bin Bae,Won-Tak Cho,Hee Sam Na,Jin Chung Korean Academy of Periodontology 2023 Journal of Periodontal & Implant Science Vol.53 No.3

Purpose: An implant-supported prosthesis consists of an implant fixture, an abutment, an internal screw that connects the abutment to the implant fixture, and the upper prosthesis. Numerous studies have investigated the microorganisms present on the implant surface, surrounding tissues, and the subgingival microflora associated with peri-implantitis. However, there is limited information regarding the microbiome within the internal screw space. In this study, microbial samples were collected from the supragingival surfaces of natural teeth, the peri-implant sulcus, and the implant-abutment screw hole, in order to characterize the microbiome of the internal screw space in healthy subjects. Methods: Samples were obtained from the supragingival region of natural teeth, the peri-implant sulcus, and the implant screw hole in 20 healthy subjects. DNA was extracted, and the V3-V4 region of the 16S ribosomal RNA was sequenced for microbiome analysis. Alpha diversity, beta diversity, linear discriminant analysis effect size (LEfSe), and network analysis were employed to compare the characteristics of the microbiomes. Results: We observed significant differences in beta diversity among the samples. Upon analyzing the significant taxa using LEfSe, the microbial composition of the implant-abutment screw hole's microbiome was found to be similar to that of the other sampling sites' microbiomes. Moreover, the microbiome network analysis revealed a unique network complexity in samples obtained from the implant screw hole compared to those from the other sampling sites. Conclusions: The bacterial composition of the biofilm collected from the implant-abutment screw hole exhibited significant differences compared to the supra-structure of the implant. Therefore, long-term monitoring and management of not only the peri-implant tissue but also the implant screw are necessary.

Microepidemic of fiberglass dermatitis in the villages near thermoelectric power plant

( Minkee Park ),( Gi Hyun Seong ),( Myeong Jin Park ),( Byung Cheol Park ),( Myung Hwa Kim ),( Seung Phil Hong ) 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.1

It is presumed that many skin diseases are caused by environmental factor, but it is usually difficult to identify the direct cause. Fiberglass dermatitis is a classic example of occupational irritant contact dermatitis owing to the penetration into the skin of over 5 μm in diameter, fine and sharp particles. In May 2016, there was a fire explosion at the thermolelectric power plant, and since then, some nearby residents have appealed the itching of nonspecific aspects. The fire debris contained glass fiber, which was thought to have spread to neighboring villages and caused symptoms. In the spring of 2017, some of the residents recurred the symptoms and were referred to our dermatologic clinic. Fourty among about 600 nearby residents complained of generalized itching and showed nonspecific lesions of irritant contact dermatitis. In 9 among 40 patients, skin biopsy was performed and among them birefringent crystal-like materials were observed in the stratum corneum of seven patients in the polarized light microscope. After that, under electron microscope using Energy Dispersive X-ray analysis, the foreign matters were revealed to mainly consist of Si, Al and Ca, which is consistent with the composition of the glass fiber. Through this case, we learned that it should be considered that nonspecific irritant dermatitis pattern could be due to unidentified environmental factors.

Rational Design of CO₂ Adsorbents for Post-Combustion CO₂ Capture

Minkee Choi,Woosung Choi,Kyungmin Min 한국에너지기후변화학회 2017 한국에너지기후변화학회 학술대회 Vol.2017 No.5

Amine-functionalized porous materials have been extensively investigated as promising approach for post-combustion CO₂ capture due to their chemisorption of low-concentration CO₂ (ca. 15%) from a flue gas. However, earlier studies mainly focused on the improvement of CO₂ uptake capacities of adsorbents, and did not demonstrate practical adsorbent regeneration processes and long-term stabilities. Here we design a cost-effective and scalable synthesis of modified-polyethyleneimine/silica composite adsorbent that can simultaneously show a large CO₂ working capacity as well as outstanding stability in a practically meaningful temperature swing adsorption (TSA) condition (adsorbent regeneration under 100% CO₂ at 120 ℃) even without the intensive use of steam. Most importantly, it is first reported that controlled modification of polyethyleneimine (PEI) with epoxide-derivatives markedly reduces the heat of CO₂ adsorption and facilitates CO₂ desorption (>99%) compared to unmodified PEI (76%) during the adsorbent regeneration. The modification also assures long-term adsorbent stability over repeated TSA cycles due to remarkable suppression of CO₂-induced urea formation and oxidative amine degradations.

A case of using hair transplantation as a treatment of scarring alopecia assoicated with incontinentia pigmenti

( Minkee Park ),( Myeong Jin Park ),( Mi Soo Choi ),( Chan Hee Nam ),( Seung Phil Hong ),( Myung Hwa Kim ),( Byung Cheol Park ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.1

Incontinentia pigmenti (IP) is a rare X-linked genodermatosis caused by a mutation in nuclear factor-κ B essential modulator (NEMO) gene located on Xq28. The condition is characterized by typical cutaneous lesions and abnormalities of the central nervous system and eyes. It affects the skin in three or four stages: vesicular, verrucous and hyperpigmented, with or without an atrophic stage. The skin lesions typically follow the lines of Blaschko. A 20-year-old female presented with linear hypopigmented, atrophic skin lesions and whorled pattern of alopecia with surrounding erythema at vertex. And also associated with absence of molar teeth, hypermetropic astigmatism and urinary problem. Her mother also have an alopecia and urinary problem. Histopathologic examination showed few structure of hairs but sclerotic collagens in dermis which was consistent with scarring alopecia on scalp and superficial perivascular lymphocytic infiltration with decreased basal pigmentation on leg. Although there was no history of previous linear vesicular, verrucous or hyperpigmented lesion, she was diagnosed clinically as an Incontinentia pigmenti. After 18months of treatment of remained inflammation, she had a hair transplantation as a treatment of scarring alopecia. Here we report a case of using hair transplantation in treatment of scarring alopecia associated with IP with no recurrence.