Generation of Transgenic Pigs Carrying a Construct for Endothelial Specific Expression of CD73

Keon Bong Oh,Bella Kim,Nayoung Ko,Dae-Jin Kwon,Dong-Hoon Kim,Gi-Sun Im,Jin-Ki Park,Seongsoo Hwang 한국동물생명공학회(구 한국동물번식학회) 2011 발생공학 국제심포지엄 및 학술대회 Vol.2011 No.1

Despite of the absence of hyperacute rejection and acute humoral xenograft rejection, the organ graft of the a1,3-galactosyltransferase (GalT) gene knockouted (KO) and complement regulatory protein (CRP) expressing pig into a nonhuman primate is rejected by development of a thrombotic microangiopathy and/or a consumptive coagulopathy. Thus further introduction of genes to overcome the coagulation incompatibilities between pig and primate under GalT KO/CRP genetic background has been strongly suggested. CD73 (ecto-5'-nucelotidase) is an enzyme attached via a glycosyl phosphoinositol anchor to the extracellular membrane of endothelial cells, which catalyses the hydrolysis of adenosine triphosphate to adenosine. Loss of activity of CD73 results in activation and aggregation of platelets by a reduced capacity to convert nucleotides to adenosine. In previous study, we reported generation of GalT KO fibroblasts concurrently expressing membrane cofactor protein and produced cloned pigs by nuclear transfer of the fibroblast cells (1). In this study, we constructed a vector for expression of human CD73 under control of promoter of pig Icam2 gene expressed specifically at endothelial cells. This vector was introduced into porcine fibroblasts using the nucleofection technology, by which we had forty three fibroblasts clones carrying pIcam2- CD73 vector. Somatic cell nuclear transfer resulted in generation of two transgenic piglets survived.

RF DIN Connector의 Passive IMD 개선에 관한 연구

고윤선,정재필,오창헌,신동욱 한국항행학회 2002 韓國航行學會論文誌 Vol.6 No.3

최근 이동통신 서비스가 확대됨에 따라 인접 기지국간의 간섭문제가 증가하게 되었으며, 그에 따라 CDMA시스템의 active IMD 뿐만 아니라 PIMD (Passive Inter Modulation Distortion)에 대한 문제도 시스템 설계 시 고려되어야 한다. 본 논문에서는 RF connector 중 대표적 connector인 7/16“ DIN connector를 통하여 동촉선에서의 PIMD발생 정도를 분석하였고, PIME 개선 방안을 제안하였다. 첫째, 대부분의 전류가 통과하는 경로에는 표면조도가 좋은 금속이 전도율이 좋아 유리하며, 둘째 RF에너지가 충분ㅎ히 한 매질에서 통과할 수 있도록 최소 5m 이상으로 도금을 해야 함을 알수 있었다. 셋째, 도금 재료의 노화현상 방지를 위해 비열이 높고 전도율이 높은 금속 선택이 필수적이며, 비용절감 면에서는 삼원합금 등 대체 도금 재질 개발이 요구됨을 알 수 있었다. 현재 국내 PIMD 규격인 KTF-150dBc를 만족시키기 위해서는 7/16“ DIN connector 의 경우 도금재질에 관계없이 표면조도 6s, 도금두께 5m일때 KTF의 PIMD 규정을 만족시킬 수 있음을 알 수 있었다. Recently, as the range of mobile communication services is extended, the interference between adjacent base-stations is increased. Nowdays, on of the important factors causing interference is IMD(Inter-Modulation Distortion) problems. Not only active IMD but also passive IMD effects must be considered to design a CDMA system. In this study, we design and implement 7/16'' DIN connectors which have a various intensity of surface illumination, thickness and quality of plating material to analyze the effects of PIMD. And propose the methods for improving the PIMD characteristics: First, it is more profitable to use the metal which has good intensity of surface illumination where most of all electric currents passes through it. Secondly, we should plate metals more than 5 μm for RF energy enough to propagate in a medium. Thirdly, it is necessary to select a metal having high conductivity and specific heat to protect the aging phenomenon of plate material. And it is required to develop a new plating material to replace the current materials, such as the alloy of three components for cost reduction. We have to know that the plate which has intensity of surface illumination 6 S and the thickness of plating material 5 μm satisfy domestic PIMD specification (KTF) - 150 dBc, regardless of the plate material in case of 7/16'' DIN connector.

당뇨병과 동반된 화농성 간농양의 임상상 및 예후인자

오은숙,강무일,이원영,오기원,임동준,이소영,이정민,고승현,김성래,안유배,손현식,윤건호,차봉연,이광우,손호영,강성구 대한당뇨병학회 2000 임상당뇨병 Vol.1 No.1

연구배경: 감염질환은 혈관질환과 함께 당뇨병의 중요한 사망원인의 하나이며, 혈당조절이 불량할수록 감염 빈도가 증가됨은 잘 알려져 있다. 간농양의 발생이 있어서도 당뇨병은 중요한 기저질환 중의 하나이다. 일반적으로 간농양의 가장 흔한 원인균은 Escherichi coli라고 알려져 있으나, 최근 당뇨병을 가진 간농양 환자에서 Klesiella pneumoniae의 검출이 증가되고 있다. 또 최근 연구에 의하면 K.pneumonie가 간농양의 가장 흔한 원인균이며, K. pneumoniae에 의한 간농양은 K.pneumoniae 이외의 균주에 의한 간농양보다 당뇨병과 밀접히 관련되어 있다고 보고된 바 있다. 이에 저자들은 간농양 환자를 대상으로 당뇨병환자의 빈도를 알아보고, 그 원인균 및 특징을 비당뇨병 환자들의 경우와 비교해 보고자 하였다. 방법: 1992년 1월부터 1999년 6월까지 방사선학적 검사 혹은 수술에 의해 간농양이 확인되거나, 경피적 천자나 수술을 통한 배농액 배양, 혹은 혈액 검사에서 원인균이 증명된 182명의 환자를 대상으로 후향적 임상고찰을 실시하였다. 결과: 화농성 농양을 가진 167명의 환자(남:94명, 여:73명)중 당뇨병을 가진 환자는 54명 (남:30명, 여:24명)으로 32.3%를 차지하였다. 환자의 평균나이는 당뇨군에서 62.1 ± 13.4세, 비당뇨군에서는 55.1 ±15.5세로 당뇨군에서 높았으며(p=0.0021), 남녀간의 평균나이 비교 시 두 군 모두 여성의 나이가 의미있게 높았다. 비당뇨군에 비하여 당뇨군의 경우 저알부민혈증의 빈도와 aspartate transaminase가 증가되어있었다. 원인균주는 K. pneumoniae (당뇨군54%, 비당뇨군 39.1%), E. coli(당뇨군 17.5%, 비당뇨군 18.8%), Pseudomonas aeruginosa, Streptococcus viridans, Enterococcus 순이었으며 두 군간의 의미는 차이는 없었으나 K. pneumoniae의 경우 다른 균종에 비해 단독감염의 빈도가 높았다(82.8%). 사망률은 당뇨군에서 16.7%, 비당뇨군에서 7.1%로 당뇨군에서 의미있게 높았으며(p=0.019), 당뇨군에서의 사망환자는 모두 패혈증이 동반되어 있었다. 당뇨환자의 사망군은 생존군에 비해 당뇨병 이환기간이 길고 혼합감염의 빈도가 높았다(p=0.046). 검사실 소견에서는 총 빌리루빈 및 알카리성 포스파타제의 증가가 관찰되어 있었다. 결론: E. coli가 간농양의 주된 원인균이라는 기존 보고와는 달리 당뇨군과 비당뇨군 모두 K. pneumoniae가 간농양의 주된 원인균이었다. 또한 당뇨 유병기간이 길고 당뇨조절이 불량한 환자에서 혼합감염이며 총 빌리루빈 및 알카리성 포스파타제의 증가등과 같은 위험인자가 존재할 경우 사망률이 증가될 수 있으므로 이들 군에서는 적극적인 치료가 필요할 것으로 사료된다. Background: Liver abscesses are commonly associated with underlying disease, particularly diabete mellitus. The number of the liver abscesses caused by Klebslella pneumoniae in diabetic patient has been increased in Korea nowadays. This study was conducted to clarify the clinical presentation and prognostic factors of pyogenic liver abscesses, especially in diabetic patients and to determine the proportion of K. pneunomiae as a pathogen in liver abscess in Korea. Methods: Medical records of 167 patients treated for pyogenic liver abscess from January, 1992 through June, 1999 were reviewed retrospectively in detail. Major Pathogenic organism, clinical manifestations, prognostic factors, the importance of diabetes mellilus as an underlying disease and its effect on clinical features and prognosis were analyzed. Results: Among 167 cases of pyogenic liver abscess, underlying diabetes mellitus was present in 32.3%. The mean age of patients was 62.7 13.4 years in diabetic liver abscess group and 55.1 15.5 years in non-diabetic liver abscess group. Most liver abscesses were cryptogenic in origin or secondary to the billary tree diseases. The clinical presentations among the two groups were not significantly different. When compared to patients without diabetes, patients with diabetes had significantly higher proportions of hypoalbuminemia and elevated aspartate transaminase level. The most common organism of the pyogenic abscess was K. pneumoniae in both groups. Percutaneous drainage of the abscess with appropriate antibiotics was the most commonly used therapeutic modality in liver abscess. The mortality rate of diabetic liver abscess is 16.1 % and 7.1% in nondiabetic liver abscess. Complications, especially septicemla, were found more frequently in patients with diabetes than in patients without diabetes (64.8% vs 28.3%, septicemia : 31.5% vs 9.7%). The factors influencing mortality in the diabetic liver abscess were disease duration, mixed infection, presence of septicemia, elevated bilirubin and alkaline phosphatase. Conclusions: In contrast to prior report that the E. coli was the most common pathogen in liver abscess, we found that K. pneumoniae was the most common organism cultured in liver abscess. Diabetic patients have more complications and higher mortality than patients without diabetes. Early detection and proper treatment are needed to improve the outcome for diabetic patient with liver abscess.

흰쥐의 악골에 동종 이식한 태아 치아싹의 장기간 발육

고동현,정한성,김성오,이제호,최형준,최병재 대한소아치과학회 2007 大韓小兒齒科學會誌 Vol.34 No.1

치아우식증이나 치주질환으로 치아를 상실한 경우 여러 가지 방법으로 수복 치료할 수 있으나 그 중에서 임플란트와 치아 이식에 대한 관심이 높아지고 있다. 최근에는 치아 이식에 대한 성공률을 높이기 위해서 치아를 형성시키고 발육시키는 과정에 관한 많은 연구가 이루어지고 있다. 치아싹 이식은 생체 내와 생체 외에서 연구되고 있고, 생체 내 이식은 쥐와 생쥐, 고양이, 개 등 여러 동물에서 시행되고 있다. 이러한 생체 내 이식은 대부분 구강 외에서 시행되고 있으며 구강 내 이식에 대한 연구는 드물다. 본 연구는 악골 내에 이식한 치아싹이 발육되고 석회화되는지 관찰하기 위하여 성숙한 흰쥐의 상악 제 1 구치를 발치하고 그 발치와에 임신 13.5일 된 태아쥐에서 모상기의 하악 제 1 구치의 치아싹을 이식하고 2. 6 개월 후 회생하여 방사선학적 그리고 조직학적으로 관찰하여 다음과 같은 결과를 얻었다. 1. 2 개월과 6 개월 동안 악골 내에 이식한 치아싹은 석회화된 치아 조직이 형성 되었고 치아 조직에서 상아질과 백악질, 치수 조직이 관찰되었으며 법랑질 공간 주변은 상피로 둘러싸여 있었다. 2. 6 개월 동안 구강 상피 하방에 위치한 치아 조직은 상피로 둘러싸여 있었고 주위에 치주인대 및 결합조직이 관찰되었다. 3. 이식한 시간이 경과함에 따라 치아 형성이 진전되었으나 치아 조직은 크기가 작았고 형태학적으로 완전하지 못하였다. In case of missing tooth caused by dental caries or periodontal disease, it can be restored by various methods, and there has been much interest in implant and tooth transplantation. The success of tooth transplantation is going to be attained through the knowledge of growth, development and calcification of tooth. Tooth transplantation has been experimented in vivo and in vitro. Many animals such as rats, mice, cats and dogs are used for tooth transplantation experiment in vivo. In most experiments, tooth was transplanted into the extraoral site, but rare into the intraoral site. In this study, to observe the capacity of formation and mineralization of tooth germ, first molar of a matured white rat was extracted and the cap stage tooth germ of a 13.5 Embryonic day embryo rat was transplanted into the extracted socket. The rats were killed 6 months later and the radiographical and histological results are as followings. 1. Tooth germ transplanted for 2 and 6 months are developing calcified tooth material such as dentin, cementum, pulp tissue, and epithelium around enamel space in the maxilla was seen. 2. The epithelium around enamel space was located beneath the oral epithelium and contained connective tissue and periodontal ligament. 3. Tooth formation was progressed as transplantation period, but the size of newly formed tooth was small and the shape of tooth was incomplete.

신경망에 의한 확대 I-PD제어계의 구성

강동원,조재오,이현철,하홍곤,고태언 동의대학교 산업기술개발연구소 2000 産業技術硏究誌 Vol.14 No.-

Many control techniques have been proposed in order to improve the control performance of discrete-time domain control system. In the position control system using a DC servo motor as a driver, the response-characteristic of system is controlled by the I-PD controller. In the I-PD control system, the transient response characteristic is more increased and settling time gets longer if gains of I-PD controller are unsuitable. In this paper, a expanded I-PD control system is constructed by inserting a pre-compensator at output terminal of I-PD controller. it is implemented by neural network with two hidden layers. From the result of computer simulation in the proposed control algorithm, its usefulness is verified.

외상성 교합으로 인한 어린이의 치주질환

최병재,고동현,김성오,이제호,손흥규 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.3

외상성 교합은 교합력의 결과로서 치주조직에 가해지는 손상이다. 주된 증상은 치아의 동요도이고, 통증, 타진에 민감, 열에 민감한 증상이 동반될 수 있으며 교합력에 의해 치아가 이동을 할 수도 있다. 만성으로 진행시 치아의 과도한 교모가 나타나며 방사선학적으로 치근막 공간의 비후, 치조백선의 비후, 치조골의 방사선 투과성, 치근흡수 등이 나타날 수 있다.외상성 교합은 치주질환의 원인과 관련되어 있다. 증가된 치아동요도를 야기하며 외상성 교합 자체는 치은염과 치주낭을 발생시키지 않으나 국소적 치태와 염증이 존재하고 있는 하에서 골소실, 치주낭이 발생할 수 있다. 치은퇴축은 외상성 반월, 맥콜스 팽윤, 스틸만 균열의 형태로 나타난다. 본 증례는 하악 유견치 부위의 치주질환을 주소로 내원한 5세 남아로서 상하악 유견치의 조기 접촉에 의해 하악 좌우측 유견치의 중증도의 동요도, 교합마모, 치은 퇴축, 치조골 파괴의 증상이 나타났기에 보고하는 바이다. Trauma from occlusion(TFO) is injury to the periodontal tissue as a result of occlusal forces. Mobility is a common clinical sign of occlusal trauma. In acute occlusal trauma, this may be accomanied by pain, tenderness to percussion, thermal sensitivity, and pathologic tooth migration. Chronic occlusal trauma may be marked by excessive wear and gingival recession. Radiographic finding include a widened periodontal ligament space, radiolucence and condensation of the alveolar bone, and root resorption. TFO is related to the pathogenesis of periodontal disease. It can cause increased tooth mobility. TFO itself does not initate or aggravate marginal gingivitis or initiate periodontal pockets. Active trauma can accelerate bone loss, pocket formation and gingival recession depending on the presence of local irritants and inflammation. Gingival recession associated with occlusal forces includes traumatic crescent, McCall's festoon and Stillman's cleft. TFO plays a minor role in the pathogenesis of early to moderate periodontitis. A 5-year-old male visited Yonsei University Pedodontics clinic with a chief complaint about gingival recession. Mobility, excessive wear, gingival recession were detected by clinical exam on the both mandibular deciduous canine. On the radiographic view, vertical alveolar bone loss was observed on both mandibular deciduous canine.

Injectable TGF-beta 3-conjugated hyaluronic acid hydrogel for cartilage regeneration

Ko, Ki Seong,Lee, Jung Seok,Park, Kyung Min,Lee, Yunki,Oh, Dong Hwan,Son, Joo Young,Kwon, Oh Hee,Eom, Min Yong,Park, Ki Dong Techno-Press 2015 Biomaterials and biomedical engineering Vol.2 No.1

Facile immobilization of growth factors in hyaluronic acid (HA) hydrogels using dual enzymes is reported in the paper. The hydrogels were formed by using horseradish peroxidase (HRP) and hydrogen peroxide ($H_2O_2$) and transforming growth factor-${\beta}3$ (TGF-${\beta}3$) was covalently conjugated on the hydrogels in situ using tyrosinase (Ty) without any modifications. For the preparation of hydrogels, HA was grafted with poly(ethylene glycol) (PEG), which was modified with a tyrosine. The gelation times of the HA hydrogels were ranging from 415 to 17 s and the storage moduli was dependent on the concentration of $H_2O_2$ and Ty (470-1600 Pa). A native TGF-${\beta}3$ (200 ng/mL) was readily encapsulated in the HA hydrogels and 17% of the TGF-${\beta}3$ was released over 1 month at the Ty concentration of 0.5 KU/mL, while the release was faster when 0.3 KU/mL of Ty was used for the encapsulation (27%). It can be suggested that the growth factors resident in the hydrogels for a long period of time may lead cells proliferating and differentiating, whereas the growth factors that are initially released from the hydrogels can induce the ingrowth of cells into the matrices. Therefore, the dual enzymatic methods as facile gel forming and loading of various native growth factors or therapeutic proteins could be highly promising for tissue regenerative medicines.

Injectable TGF-beta 3-conjugated hyaluronic acid hydrogel for cartilage regeneration

Ko, Ki Seong,Lee, Jung Seok,Park, Kyung Min,Lee, Yunki,Oh, Dong Hwan,Son, Joo Young,Kwon, Oh Hee,Eom, Min Yong,Park, Ki Dong Techno-Press 2015 Biomaterials and Biomechanics in Bioengineering Vol.2 No.1

Facile immobilization of growth factors in hyaluronic acid (HA) hydrogels using dual enzymes is reported in the paper. The hydrogels were formed by using horseradish peroxidase (HRP) and hydrogen peroxide ($H_2O_2$) and transforming growth factor-${\beta}3$ (TGF-${\beta}3$) was covalently conjugated on the hydrogels in situ using tyrosinase (Ty) without any modifications. For the preparation of hydrogels, HA was grafted with poly(ethylene glycol) (PEG), which was modified with a tyrosine. The gelation times of the HA hydrogels were ranging from 415 to 17 s and the storage moduli was dependent on the concentration of $H_2O_2$ and Ty (470-1600 Pa). A native TGF-${\beta}3$ (200 ng/mL) was readily encapsulated in the HA hydrogels and 17% of the TGF-${\beta}3$ was released over 1 month at the Ty concentration of 0.5 KU/mL, while the release was faster when 0.3 KU/mL of Ty was used for the encapsulation (27%). It can be suggested that the growth factors resident in the hydrogels for a long period of time may lead cells proliferating and differentiating, whereas the growth factors that are initially released from the hydrogels can induce the ingrowth of cells into the matrices. Therefore, the dual enzymatic methods as facile gel forming and loading of various native growth factors or therapeutic proteins could be highly promising for tissue regenerative medicines.

Superamphiphobic Silicon-Nanowire-Embedded Microsystem and In-Contact Flow Performance of Gas and Liquid Streams

Ko, Dong-Hyeon,Ren, Wurong,Kim, Jin-Oh,Wang, Jun,Wang, Hao,Sharma, Siddharth,Faustini, Marco,Kim, Dong-Pyo American Chemical Society 2016 ACS NANO Vol.10 No.1

<P>Gas and liquid streams are invariably separated either by a solid wall or by a membrane for heat or mass transfer between the gas and liquid streams. Without the separating wall, the gas phase is present as bubbles in liquid or, in a microsystem, as gas plugs between slugs of liquid. Continuous and direct contact between the two moving streams of gas and liquid is quite an efficient way of achieving heat or mass transfer between the two phases. Here, we report a silicon nanowire built-in microsystem in which a liquid stream flows in contact with an underlying gas stream. The upper liquid stream does not penetrate into the lower gas stream due to the superamphiphobic nature of the silicon nanowires built into the bottom wall, thereby preserving the integrity of continuous gas and liquid streams, although they are flowing in contact. Due to the superamphiphobic nature of silicon nanowires, the microsystem provides the best possible interfacial mass transfer known to date between flowing gas and liquid phases, which can achieve excellent chemical performance in two-phase organic syntheses.</P>

The Influence of Femoral Internal Rotation on Patellar Tracking in Total Knee Arthroplasty Using Gap Technique

Dong Oh Ko,Song Lee,Jin Hak Kim,Il Chan Hwang,Sung Jun Jang,Jin Jung 대한정형외과학회 2021 Clinics in Orthopedic Surgery Vol.13 No.3

Background: Femoral internal rotation in total knee arthroplasty (TKA) is well known as one of the main causes of patellar maltracking. Although femoral internal rotation in TKA is considered unacceptable due to the risk of patellar maltracking, it is sometimes required for ligament balancing. We evaluated the influence of femoral internal rotation on patellar tracking in TKA performed using the gap technique. Methods: From April 2008 to May 2018, 1,612 cases of TKA were done. Among them, 245 cases of TKA for osteoarthritis were followed up for at least 1 year and included in this study. We compared patellar tracking in two groups; group I consisted of 99 cases whose femoral rotation was less than 0° and group II consisted of 146 cases whose femoral rotation was 3°–5° external rotation. Preoperative femoral rotation was measured with the condylar twist angle (CTA) by using computed tomography. The patella was replaced in all cases. Patellar tracking was evaluated with patellar tilt angle (lateral tilt [+] and medial tilt [–]) in the merchant radiograph. Statistical analysis was done using Mann-Whitney U-test. Clinical assessment was performed using the Knee Society clinical rating system. Results: The preoperative CTA was 5.3° ± 1.6° in group I and 5.4° ± 1.6° in group II, showing no statistically significant difference between groups (p = 0.455). Intraoperative femoral rotation was –0.5° ± 0.8° in group I and 3.9° ± 0.8° in group II when the gap technique was used (p < 0.001). The postoperative patellar tilt angle was –0.4° ± 3.6° in group I and 0.1° ± 4.1° in group II with no statistically significant difference (p = 0.251). Conclusions: Compared with femoral external rotation, femoral internal rotation with ligament balance in TKA was not more associated with patellar maltracking. Therefore, patellar tracking might be related with ligament balance in flexion regardless of the anatomic femoral rotational alignment.