학동기이전 소아 안와골절 환자의 임상양상과 예후

박정현,김대현,Jung Hyun Park,Dae Hyun Kim 대한안과학회 2011 대한안과학회지 Vol.52 No.12

Purpose: To evaluate the clinical aspects associated with the preoperative and postoperative state of blow-out fractures in preschool children. Methods: The authors of the present study retrospectively reviewed 11 cases of blow-out fracture repaired by orbital reconstruction. Results: The most common cause of fracture was a traffic accident (45%); there were 7 cases (63%) of inferior wall fracture and 7 cases (63%) of trapdoor-type fracture. All patients with trapdoor-type fractures had nausea and vomiting. After the operation, the majority of patients (88%) had mild ocular motility restriction and diplopia. Conclusions: In preschool children, systemic symptoms such as nausea and vomiting presented frequently. In addition, complications such as restriction in ocular movement and diplopia often developed postoperatively. J Korean Ophthalmol Soc 2011;52(12):1490-1495

자연 퇴행한 양안 망막모세포종

박정현,정호경,곽상인,유영석,Jung Hyun Park,Ho Kyung Chung,Sang In Kwarg,Young Suk Yu 대한안과학회 2006 대한안과학회지 Vol.47 No.12

Purpose: To report four cases of spontaneous regression of retinoblastoma. Methods: The clinical courses of two patients were retrospectively investigated: a patient who has been diagnosed with bilateral retinoblastoma and has survived more than six years after his parents refused treatment and a patient with bilateral retinal lesions who has survived nine years whose sister was treated for unilateral retinoblastoma. Results: A nine-year-old girl, diagnosed with bilateral retinoblastoma when she was three months old, remained well for nine years after her parents refused to seek treatment. The right eye had three retinal masses that had regressed, and the left eye showed signs of phthisis and was enucleated for a cosmetic purpose. Microscopic examination of the left eye showed a mass, which consisted mostly of fibroblasts and ground substance and a few retinoblasts without mitotic figures. A six-year-old boy with a family history of retinoblastoma presented with regressed retinal masses in both of his eyes at the first funduscopic examination. The retinal lesions showed no change until his ninth year. Conclusions: Two cases of spontaneous regression of bilateral retinoblastoma were observed. No distant metastasis was detected during long-term follow-up. The retinal lesions were similar to regressed masses after treatment.

Application of Fluorescence Polarization Immunoassay for the Screening of Ochratoxin A in Unpolished Rice

박정현,정덕화,이인선,Park, Jung-Hyun,Chung, Duck-Hwa,Lee, In-Seon Korean Society of Life Science 2006 생명과학회지 Vol.16 No.6

To High Throughput Screening (HTS), a homogeneous fluorescence polarization immunoassay (FPIA) was developed for the quantitative determination of ochratoxin A(OTA) using a $Victor^3$ (PerkinElmer). The homologous tracer, fluorescein-labelled OTA-EDF were synthesized and a specific OTA antibody has been used in the development of the method. It allowed the determination of OTA in the concentration range 0.5-200 ng/ml, with the detection limit of 0.3 ng/ml. The method developed was highly specific and reproducible. OTA spikes in unpolished rice extracts were determinable by FPIA with good recovery. For naturally contaminated unpolished rice samples some disagreement was observed between the results obtained by FPIA and HPLC, which could be related to the a little matrix effect observed for FPIA. Further research is needed to validate the procedure. On the basis of these initial results, this FPIA appears to meet the performance criteria for OTA screening of food samples without a complicated clean-up. 식품안전에 대한 관심이 증가되고 있는 현재, 생물학적 화학적 위해요소로 분류되고 있고, 현재 많은 나라에서 규제치를 설정하고 있는 곰팡이 독소인 ochratoxin A(OTA)에 대한 정량적 측정이 가능한 고속검색법을 개발 하고자 단클론성 항체를 이용하여, 측정시 분리과정이 필요 없는 형광편광면역분석법(FPIA)을 개발하고 최적화 시켰다. 동일구조를 가지는 형광물질 표식자인 OTA-EDF를 합성하여 OTA에 대한 특이항체와 경쟁반응을 시켜 나타나는 형광-편광도(mP)의 변화를 측정하였다. 이는 면역분석법의 특이성과 민감성을 충분히 만족하였다. OTA의 검출범위는 0.5-200 ng/ml였고, 검출한계는 0.3 ng/ml였다. 개발된 분석법은 다른 곰팡이 독소들과의 교차반응은 없었고 높은 특이성과 재현성 및 회수율을 나타내었다. HPLC 방법에 의한 회수율은 88-84%로 다소낮게, FPlA법의 회수율은 90-110%로 다소 높게 나타났다. 16점의 현미시료를 분석하였을 때, 2점이 상관관계가 높게 12-20 ppb 정도 오염된 것으로 나타났다. 4점은 FPIA 및 HPLC 모두에서 음성으로 판정되었다. 개발된 FPIA는 복잡한 전처리 방법이 필요 없는 신속한 검색이 가능하므로, 식품 및 환경에서의 OTA 잔류 검사에 유용하게 사용될 수 있을 것이다.

3D 프린팅 기술을 활용한 낙상충격 보호패드 구조설계 및 필라멘트 소재에 따른 특성 비교

박정현,정희경,이정란,Park, Jung Hyun,Jung, Hee-Kyeong,Lee, Jeong Ran 한국의류학회 2017 한국의류학회지 Vol.41 No.5

This study uses 3D printing technology to design and fabricate a fall impact protection pad with a spacer fabric structure. The design of the pads consists of hexagonal three-dimensional units connected in a honey-comb shape; in addition, the unit consists of a surface layer and a spacer layer. Protect pads were designed as either a hexagonal type or diamond type according to the surface layer structure; subsequently, a spacer filament was also designed as the most basic I-shape type. Designed pads were printed using four types of flexible filaments to select suitable material for a fall impact protection pad. Impact protection performance and bending stiffness were evaluated for the eight type of pad outputs. As a result of the impact protection performance evaluation, when the force of 6,500N was applied, the force passed through the pad was in the range of 1,370-2,132N. FlexSolid$^{(R)}$ and Skinflex$^{TM}$ showed good protection performance and cubicon flexible filament showed the lowest protection. NinjaFlex$^{(R)}$ was found to be the most flexible in the bending stiffness evaluation.

PSZ, Al₂O₃, TiO₂를 반응소결하여 제조한 쾌삭(快削) 세라믹스

박정현,정동식,이원재,김일수,Park, Jeong Hyun,Jung, Dong Sik,Lee, Won Jae,Kim, Il Soo 한국세라믹학회 2012 한국세라믹학회지 Vol.49 No.6

Machinability is important in engineering applications, especially in the current micro-electronics industry. Most ceramic components have complex shapes and hence require machining generally with diamond tools, which incurs a high production cost. Recently, h-BN-containing machinable ceramics have been developed, but these materials are very expensive due to the high raw materials and production costs. Therefore, the development of low-cost machinable ceramics is necessary. In this study, inexpensive $Al_2TiO_5$ was studied as a replacement for h-BN. $Al_2O_3$, $TiO_2$ and partially stabilized $ZrO_2$(PSZ) powders were mixed with various mole ratios and were sintered at $1500^{\circ}C$ for 1 h. The density, hardness and strength were then measured. The phase analysis and microstructures were observed by XRD and SEM, respectively. The machinability of each specimen was tested by micro-hole machining. The results of this research showed that the produced composites could be used as low-cost machinable ceramics.

사람 Mesenchymal stromal cell(hMSC) 분리를 위한 간소화된 방법에 대한 연구

박정현,김경화,이용무,구영,류인철,한수부,정종평,Park, Jung-Hyun,Kim, Kyoung-Hwa,Lee, Yong-Moo,Ku, Young,Rhyu, In-Chul,Han, Soo-Boo,Chung, Chong-Pyoung 대한치주과학회 2004 Journal of Periodontal & Implant Science Vol.34 No.1

많은 연구들에서 hMSC를 얻기 위해 centrifugation, fluoroscence activated cell sorter(FACS), magnetic activated cell sorter(MACS)가 이용되어져 왔다. 그러나 centrifugation만을 이용한 경우 순도가 떨어지며 FACS나 MACS의 경우에는 비용, 시간이 많이 드는 단점이 있다. 따라서 이 연구에서는 antibody cocktail을 이용하여 hMSC를 좀더 쉽게 얻어내는 방법에 대해 알아보았다. 사람의 골반에서 12G의 바늘을 이용하여 골수를 흡입한 후 heparin이 들어있는 시험관에 넣고 처리과정을 시행하기 전에 냉장고에 보관하며 가능한 한 빨리 처리 과정을 실시한다. 얻은 골수에 적당량의 RosetteSep( Stemcell Technologies)을 첨가한 후 실온에서 20분간 반응시킨다. 그 후 적당량의 Ficoll-paque위에 골수와 RosetteSep의 혼합물을 섞이지 않게 올리고 원심분리를 이용하여 원하는 세포층을 얻어낸다. 이 세포층을 따로 분리한 뒤 배양한다. 배양 시 세포가 80%이상 차기 전에 계속 passage를 시행하며 배양한다. 이는 세포가 밀도가 높아져 원치 않는 세포로 분화되는 것을 막기 위함이다. 배양된 세포가 다양한 분화능력을 가지고 있는지 알아보기 위해 세 가지로 분화를 유도하였다. 적절한 배지와 적절한 환경에서 배양함으로써 얻어진 세포를 osteoblast, chondroblast, adipocyte로 분화를 유도하였다. 분화된 세포가 원하는 형질의 세포로 분화되었는지를 확인하기 위하여 osteoblast의 경우 alizarin red staining, alkaline phosphatase activity, chondroblast의 경우 toluidine blue staining, adipocyte의 경우 Oil-Red-O staining으로 염색하여 분화를 확인하였다. 분리해낸 세포는 각각 세 가지 세포로 분화가 되었으며 이는 RosetteSep이 hMSC를 성공적으로 분리해냈다는 것을 보여준다. 그러나 모든 세포가 분화를 보이지는 않았으며 따라서 hMSC의 순도를 높이기 위한 연구가 더 필요하다. RosetteSep을 이용하면 다른 방법들 보다 쉽게 hMSC를 얻을 수 있으나 기존의 방법과 순도의 측면에서 더 비교할 필요가 있다.

경북지역에서 파종시기가 춘파 귀리의 생육특성과 사료작물 종자생산에 미치는 영향

박정현,최광원,정기웅,조익환,Park, Joung-Hyun,Choi, Gwang-Won,Jung, Gi-Woung,Jo, Ik-Hwan 한국초지조사료학회 2016 한국초지조사료학회지 Vol.36 No.4

경북 지역에서 수요가 높은 사료작물 중 춘파 귀리(Avena sativa L., cv. High Speed)의 안정적인 종자생산을 위하여 2015년과 2016년 2년간 파종 시기별(2월 말일, 3월 10일, 20일)로 파종(130 kg/ha) 하였을 때 귀리의 생육 특성, 종자 생산성 및 사료가치를 조사하였다. 출수기, 개화기 및 성숙기는, 매년 2월 말일 파종구와 3월 10일 파종구가 1~2일 차이로 거의 비슷하였다. 2월 말일 파종의 경우, 귀리의 초장이 타 파종구 대비 유의적으로 길었고 (p<0.05) 수장(穗長)은 2016년 최대 1cm 유의적으로 길었으며 단위 면적($m^2$)당 수수(穗數)도 2015년 유의적으로 가장 많았다($416.7ea/m^2$). 이상, 파종 시기별 춘파 귀리는 2월 말 파종이 초장, 간장, 수장 및 단위 면적($m^2$)당 수수 등에서 비교적 양호한 생육을 보였다. 1수립수(穗粒數)는, 2월 말일 파종구가 2016년 및 두 해 평균 각각 56.3 및 63.3개로 유의적으로 많았다(p<0.05). 1수립중(穗粒重)도, 2월 말일 파종구가 2016년 및 두 해 평균 각각 1.72 및 2.00 g/spike로 유의적으로 높았다(p<0.05). 종실 수량의 경우, 2월 말일 파종구에서 3월 10, 20일 파종구 보다 높은 수준이었으며 두 해 평균 가장 높은 종자 생산성(6,243 kg/ha)을 보였다(p<0.05). 조단백질, 조지방, 조섬유, ADF, NDF 및 TDN 함량에서 파종기와 무관하게 귀리의 사료가치가 우수한 것으로 평가되며 이상의 결과로 볼 때, 경북 경주지역에서 춘파 귀리의 적절한 파종 시기는, 종자 생산성 면에서 2월 말일이 효과적이었다. The objective of this study was to efficiently produce forage crop seed of spring oat (Avena sativa L., cultivar High Speed) in Gyeongbuk area. Forage crop oats (130 kg/ha) were sown with a randomized block design. They were sown in triplicates in 2015 and 2016 using basal fertilizer of 70 kg N, 74 kg P, and 39 kg K/ha. Agronomic traits and seed production of oats were investigated to determine the influence of seeding dates (February 28/29th, March 10th, and March 20th). Heading, flowering, and maturing dates of these oats sown on February 28/29th and March 10th were almost close to each other with 1-2 days of difference for all test plots. For oats sown on the last day (28/29) of Feb., plant heights (111.6-122.6 cm) were significantly longer than those sown in March each year. In addition, panicle number ($416.7per\;m^2$) and panicle length (17.3 cm) of oats sown on the last day of February were also significantly (p < 0.05) larger than those of oats sown in March in 2015 and 2016, respectively. Based on these results, it is recommended to sow these oats on the last day of February to have better agronomic traits in terms of plant height, stem length, panicle length, and panicle number $per\;m^2$. Grain numbers (56.3 and 63.3) and kernel weights (1.72 and 2.00 g) per spike in plots of oats sown on the last day of February were also significantly (p < 0.05) larger than those of oats in other plots in 2016 and in the average of 2015~2016, respectively. The highest grain yield (6,243 kg/ha) was obtained when oats were sown on the last day of February. Feed value of harvested oats was good in terms of proximate compositions including fiber contents and TDN contents. In conclusion, sowing on the last day of February is the most effective way to increase seed production of spring oats in Gyeongbuk area of Korea.

Stem Cell Based Strategies for the Treatment of Degenerative Retinal Diseases

박정현,구승엽,조명수,이학섭,최영민,문신용,유형곤,Park, Jung-Hyun,Ku, Seung-Yup,Cho, Myung-Soo,Lee, Hak-Sup,Choi, Young-Min,Moon, Shin-Yong,Yu, Hyeong-Gon The Korean Society for Reproductive Medicine 2010 Clinical and Experimental Reproductive Medicine Vol.37 No.3

망막 질환에서의 줄기세포 치료는 이전까지 치료가 불가능하다고 여겨졌던 환자들에서 시력을 향상시킬 수 있는 가능성 때문에 주목 받고 있다. 본문에서는 망막 전구세포의 분화를 위해 사용되는 태아 줄기세포, 배아줄기세포 및 성체줄기세포 등 다양한 세포 종류와, 내인적, 외인적 인자 및 이식 방법에 대해 논의하였다. 망막색소상피세포뿐만 아니라 시각세포 전구체로 성공적으로 분화시킨 실험적 연구가 보고되고 있다. 줄기세포기반치료는 아직 한계가 있지만 망막 질환 환자에서 시력을 회복하기 위한 보다 근본적인 치료 방법으로 기대되고 있다. Stem-cell therapy has the potential to improve vision in patients with untreatable retinal disease. Various types of cell source including fetal, embryonic and adult stem cells, intrinsic and extrinsic factors for differentiation into retinal progenitors and transplantation mode were discussed in this review. Experimental approaches have successfully induced photoreceptor precursor cells and retinal pigment epithelium. Stem-cell-based therapy is a promising treatment to restore vision in patients with retinal disease, in spite of the challenges.

수포각막병증에서 양막 이식술의 효용성

박정현,정진욱,위원량,이진학,김미금,이재림.Jung Hyun Park. M.D.. Jin Wook Jeoung. M.D.. Won Ryang Wee. M.D.. Ph.D... Jin Hak Lee. M.D. Ph.D... Mee Kum Kim. M.D.. Ph.D... Jae Lim Lee. M.D. 대한안과학회 2007 대한안과학회지 Vol.48 No.8

Purpose: To evaluate the efficacy of amniotic membrane (AM) transplantation in symptomatic bullous keratopathy using cryo-preserved or lyophilized AM. Methods: Eight bullous keratopathic patients, who experienced intractable pain despite medication and the application of a therapeutic lens, underwent permanent AM transplantation with 5 cryo-preserved and 3 lyophilized AMs following removal of epithelium using a trephine. The time to re-epithelization and the subsidence of pain were evaluated retrospectively. Results: Mean follow-up was 252±171.0 days. Pain relief and re-epithelization were obtained in all eight patients. The times to complete relief of pain was 32.2±22.7 days in patients with cryo-preserved AM transplantations (n=5) and 22.0±18.0 days in those with lyophilized AM transplantations (n=3) (p=0.549, Mann-Whitney U test). Respective times to re-epithelization were 25.4±20.7 days and 23.0±25.2 days (p=0.297). There were no significant differences in the diameter of transplanted AMs between the two groups (7.6±0.2 vs. 7.3±0.3 mm, p=0.172). Conclusions: Permanent AM transplantation effectively reduced the intractable pain caused by epithelial bulla. Whether the AM was cryo-preserved or lyophilized did not affect the efficacy of the treatment.

케미컬 라이트에 의한 각결막 화상 1예

박정현,송낭희,지남철,고재웅,Jung Hyun Park,MD,Nang Hee Song,MD,Nam Chul Chi,MD,PhD,Jae Woong Koh,MD,PhD 대한안과학회 2010 대한안과학회지 Vol.51 No.9

Purpose: Chemical lights, also called Luminous Sticks, consist of a solution of diphenyl oxalate (C14H10O4) and hydrogen peroxide (H2O2). Human tissue can be damaged when the mixed solution contacts the human body. The authors report a single case of chemical injury of keratoconjunctiva by exposure to chemical lights. Case summary: A 47-year-old man’s right eye accidentally contacted the fluorescent material when breaking a Luminous Stick 7 days before being referred to our clinic. He had pain in the right eye and experienced visual loss. The patient’s best corrected visual acuity in the right eye was 20/50. An ulcerative lesion with edema at the inferior bulbar and palpebral conjunctiva and coneal epithelial defect was observed upon biomicroscopic examination. The patient was hospitalized and antibiotics, steroids, mydriatic and artificial tear eye drops were applied for treatment. After 9 days of treatment, the best corrected visual acuity of the patient recovered to 20/20, and the conjunctiva and cornea were mostly healed. No complication was observed. Conclusions: Chemical lights are commonly used in concerts and festivals. If the contents contact the eyes when breaking the chemical lights, various chemical burns can occur and cause ophthalmologic complications. Since no regulations have been passed regarding chemical lights, safety education and supervision are considered to be necessary for children. J Korean Ophthalmol Soc 2010;51(9):1282-1286