Preparation of Thermo-Responsive and Injectable Hydrogels Based on Hyaluronic Acid and Poly(N-isopropylacrylamide) and Their Drug Release Behaviors

Ha Dong In,Lee Sang Bong,Chong Moo Sang,Lee Young Moo,Kim So Yeon,Park Young Hoon The Polymer Society of Korea 2006 Macromolecular Research Vol.14 No.1

Copolymers composed of hyaluronic acid (HA) and poly(N-isopropylacrylamide) (PNIPAAm) were prepared to create temperature-sensitive injectable gels for use in controlled drug delivery applications. Semi-telechelic PNIPAAm, with amino groups at the end of each main chain, was synthesized by radical polymerization using 2-aminoethanethiol hydrochloride (AESH) as the chain transfer agent, and was then grafted onto the carboxyl groups of HA using carbodiimide chemistry. The result of the thermo-optical analysis revealed that the phase transition of the PNIPAAm-grafted HA solution occurred at around 30$\∼$33$^{circ}C$. As the graft yield of PNIPAAm onto the HA backbone increased, the HA-g-PNIPAAm copolymer solution exhibited sharper phase transition. The short chain PNIPAAm-grafted HA ($M_{w}$=6,100) showed a narrower temperature range for optical turbidity changes than the long chain PNIPAAm-grafted HA ($M_{w}$=13,100). PNIPAAm-grafted HA exhibited an increase in viscosity above 35$^{circ}C$, thus allowing the gels to maintain their shape for 24 h after in vivo administration. From the in vitro riboflavin release study, the HA-g-PNIPAAm gel showed a more sustained release behavior when the grafting yield of PNIPAAm onto the HA backbone was increased. In addition, BSA released from the PNIPAAm-g-HA gels showed a maximum concentration in the blood 12 h after being injected into the dorsal surface of a rabbit, followed by a sustained release profile after 60 h.

Bloodstream Infections and Clinical Significance of Healthcare-associated Bacteremia: A Multicenter Surveillance Study in Korean Hospitals

Son, Jun Seong,Song, Jae-Hoon,Ko, Kwan Soo,Yeom, Joon Sup,Ki, Hyun Kyun,Kim, Shin-Woo,Chang, Hyun-Ha,Ryu, Seong Yeol,Kim, Yeon-Sook,Jung, Sook-In,Shin, Sang Yop,Oh, Hee Bok,Lee, Yeong Seon,Chung, Doo The Korean Academy of Medical Sciences 2010 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.25 No.7

<P>Recent changes in healthcare systems have changed the epidemiologic paradigms in many infectious fields including bloodstream infection (BSI). We compared clinical characteristics of community-acquired (CA), hospital-acquired (HA), and healthcare-associated (HCA) BSI. We performed a prospective nationwide multicenter surveillance study from 9 university hospitals in Korea. Total 1,605 blood isolates were collected from 2006 to 2007, and 1,144 isolates were considered true pathogens. HA-BSI accounted for 48.8%, CA-BSI for 33.2%, and HCA-BSI for 18.0%. HA-BSI and HCA-BSI were more likely to have severe comorbidities. <I>Escherichia coli</I> was the most common isolate in CA-BSI (47.1%) and HCA-BSI (27.2%). In contrast, <I>Staphylococcus aureus</I> (15.2%), coagulase-negative <I>Staphylococcus</I> (15.1%) were the common isolates in HA-BSI. The rate of appropriate empiric antimicrobial therapy was the highest in CA-BSI (89.0%) followed by HCA-BSI (76.4%), and HA-BSI (75.0%). The 30-day mortality rate was the highest in HA-BSI (23.0%) followed by HCA-BSI (18.4%), and CA-BSI (10.2%). High Pitt score and inappropriate empirical antibiotic therapy were the independent risk factors for mortality by multivariate analysis. In conclusion, the present data suggest that clinical features, outcome, and microbiologic features of causative pathogens vary by origin of BSI. Especially, HCA-BSI shows unique clinical characteristics, which should be considered a distinct category for more appropriate antibiotic treatment.</P>

Valuation of ecosystem services in the organic carbon of the Pinus densiflora forest at Mt. Namsan, Seoul Metropolitan City

Lee, Eung-Pill,Lee, Soo-In,Jeong, Heon-Mo,Han, Young-Sub,Lee, Seung-Yeon,Park, Jae-Hoon,Jang, Rae-Ha,Hong, Youg-Sik,Jung, Young-Ho,Kim, Eui-Joo,Lee, Sang-Hun,You, Young-Han The Ecological Society of Korea 2019 Journal of Ecology and Environment Vol.43 No.4

Background: Standing biomass, litter production, rate of litter decomposition, amount of litter on forest floor, and amount of soil organic carbon distribution were investigated from March 2016 to November 2018 in order to evaluate the ecosystem value through organic carbon distribution in the Pinus densiflora forest at Namsan, Seoul Metropolitan City. Results: The amount of organic carbon in the Pinus densiflora forest was 261.09 ton C ha^-1 during the research period, and fixed organic carbon in plant through net photosynthesis was 3.2 ton C ha^-1 year^-1. The organic carbon in plant was 62.77 ton C ha^-1 (24.04%), in litter on the forest floor was 3.65 ton C ha^-1 (1.40%), and in soil was 194.67 ton C ha^-1 (74.56%). The value of plant, litter on forest floor, and soil organic carbon distribution were each 6,277,000 won ha^-1, 365, 000 won ha^-1, and 19,467,000 won ha^-1. The value per ton of fixed organic carbon in plant through net photosynthesis was 320,000 won ha^-1 year^-1 and the value of ecosystem services stored in carbon in the Namsan forest ecosystem was about 26.1 million won ha^-1 for 3 years. Conclusions: The results of this study suggest that the pine forests of Namsan rapidly decompose leaves due to the high atmospheric temperature and accumulate a large amount of organic carbon in the soil to provide climate control regulatory service function.

Ultrasound-Triggered Drug Release of Hydroxyapatite Coated Liposomes

조성근,위태인,하정,조선행,한건,한희동,신병철,Cho, Sung Keun,Wee, Tae In,Ha, Jeung,Cho, Sun Hang,Han, Kun,Han, Hee Dong,Shin, Byung Cheol Korean Chemical Society 2013 대한화학회지 Vol.57 No.4

리포솜은 표적 약물을 봉입하여 병소에 안전하게 전달할 수 있는 약물전달체로서 연구되고 있다. 그러나 일반적인 리포솜은 표적부위에서 약물방출이 제한적인 문제점이 있다. 따라서 본 연구에서는 리포솜의 안정성을 향상시키고 표적부위에서 외부 초음파로부터 약물의 방출을 극대화시키기 위하여 하이드록시아파타이트(hydroxyapatite, HA)가 코팅된 리포솜을 개발하였다. 대조군 리포솜은 인지질과 콜레스테롤을 이용하여 제조하였고, 대조군 리포솜의 표면에 칼슘 아세테이트, 포스포릭에시드, 그리고 25% 암모니아용액을 이용하여 HA를 코팅하였다. 모델 약물로는 독소루비신을 사용하였다. HA코팅 리포솜의 크기는 120 nm 이었고, 약물봉입효율은 95% 이상이었다. 30% 혈장용액 내에서 HA코팅 리포솜의 입자크기는 일정한 상태를 유지하였으며, 대조군 리포솜은 크기가 1.4배 증가하였다. 외부 초음파 자극에 의한 리포솜으로부터 약물 방출을 유도한 후, 방출된 약물의 세포 이입율은 HA 코팅된 리포솜이 3배 이상 대조군 리포솜에 비하여 증가하였다. 본 연구에서는 외부 초음파 자극에 의하여 리포솜으로부터 약물의 방출을 극대화시키기 위한 초음파 민감형 리포솜을 개발하였고, 본 제형은 표적부위에서 약물의 방출을 효과적으로 제어하기 위한 분야에 활용이 가능할 것이다. Liposomes, which can deliver payload at target site, have been studied as drug carrier. However, conventional liposomes have limitation for drug release at target site. Therefore, we developed hydroxyapatite (HA) coated ultrasound sensitive liposomes to increase drug release at target site and to enhance stability in blood stream. Control liposome was prepared using hydrogenated soy phosphatidylcholine (HSPC) and cholesterol, and then we assessed HA coating on the surface of control liposomes using calcium acetate, phosphoric acid, and 25% ammonium solution. Doxorubicin was used as a model drug. Size of HA coated liposomes was 120 nm and encapsulation efficiency of doxorubicin in liposomes was up to 95%. Size of HA coated liposomes are not changed in 30% serum solution, however, the control liposomes was 1.4 fold increased. After ultrasound triggered drug release from liposomes, intracellular efficiency of drug released from HA coated liposomes was 3 fold increased compared to control liposomes. In this study, we developed ultrasound sensitive liposomes to enhance drug release, which will be applied in controlled drug release at disease site.

HA 라우팅 기반의 개선된 멀티캐스트 제공 방안

김인경(In-Kyeong Kim),하정락(Jeong-Lak Ha),현은희(Eun-Hee Hyun),김상하(Sang-Ha Kim) 한국정보과학회 2001 한국정보과학회 학술발표논문집 Vol.28 No.2Ⅲ

IETF Mobile IP는 이동 컴퓨팅 환경에서 IP 멀티캐스트를 지원하기 위한 메커니즘으로 HA 기반 라우팅과 FA 기반 라우팅을 간략히 언급하고 있다. FA 기반 라우팅의 경우, 단말기 이동 시 멀티캐스트 트리를 재구성하는 오버헤드가 존재하는 단점이 있다. 반연, HA 기반 라우팅의 경우, 단말기 이동시 경로 최적화가 이루어지지 않는 단점에도 불구하고, 멀티캐스트 트리 수정에 대한 오버헤드가 존재하지 않은 장점이 있다. 이러한 장점은 망의 안정성을 높일 수 있기 때문에 많은 연구에서 HA 기반 라우팅을 채택하고 있다. 하지만, 기존의 HA 기반 라우팅 방법에서 가장 큰 장애 요소는 터널링 집중화 현상이며, 이를 해결하기 위해 Mobile Multicast(MOM) 등에서 정성적인 방법을 제안하고 있지만, 구체적인 프로토콜이 없으며 모든 HA들이 관여하는 복잡도로 인해 실제로 망에 배치되는 데 한계성을 가진다. 본 논문에서는 현재의 Mobile IP 메시지의 간단한 확장과 FA에 멀티캐스팅을 위한 기능을 첨가하여, 터널링 집중화 현상을 해결하는 프로토콜을 제안하고자 한다. 제안되는 프로토콜은 현재의 모든 IP 멀티캐스트를 수용하고, Mobile IP와의 호환성을 유지한다.

북극 스발바드 군도 스피츠베르겐섬 콩스피요르드에서의 다환 방향족 탄화수소화합물의 분포 특성

김기범,하성용,안인영,최희선 한국환경과학회 2004 한국환경과학회지 Vol.13 No.9

In order to elucidate the polycyclic aromatic hydrocarbon concentration and its origin in arctic area, four arctic brown algae (Laminaria saccharina, L. digita, Alaria esculenta, Desmarestia aculeata), one marine invertebrate (Echinoidea) and sediments were collected from Kongsfjorden in Spitsbergen from the late July to early August. 2003. In case of macroalgae, the young blade part above growth point and the old stipes and blades beneath growth point were separated and analyzed for polycyclic aromatic hydrocarbons (PAHs) in an attempt to check the mechanism of uptake in macroalgae to accumulate PAN. There was no difference in PAH concentrations between sampling sites (Stations B and C), species. and blades beneath and above growth point. PAH concentrations in all samples collected in this study were relatively higher than those reported in other areas of arctic. Especially, station C, which is known as an unpolluted area, showed 10 times higher PAH concentration (8,765 ng/g) in sediment than station A (694 ng/g) around harbor. In addition high PAH concentration, station C had very higher proportion of methylated PAH to parent PAH in sediment than station A. Source analysis using PAH isomer pair ratios as indicators showed that Kongsfjorden area seemed to be relatively contaminated with PAH derived from direct petroleum input.

비글개에서 신원방우황청심원의 급성 및 아급성독성시험

성하정,권오경,방명주,곽형일,이진영,신대희,박대규,정규혁,윤효인,조명행 성균관대학교 약학연구소 1998 成均藥硏論文集 Vol.10 No.1

Single and 4 weeks oral administration of New wonbangwoohwangchungsimwon (NSCH) which was used l-muscone as substitutive material of musk, to beagle dogs of both sexes were performed to investigate both acute and subacute toxicity. Beagle dogs (3 males and 3 females) in acute experiments were administered orally with sinlge dose of 2,000 ㎎/㎏ and groups of 9 male and 9 female beagle dogs in subacute experiments were given daily different dosage of NSCH, 160 ㎎/㎏/day (low dosage group), 400 ㎎/㎏/day (middle dosage group), 1,000 ㎎/㎏/day (high dosage group) once a day for 4 weeks by oral route according to the Established Regulation of Korea Food and Drug Administration (1996. 4. 16). LD_50 value for beagle dogs was more than 2,000 ㎎/㎏ per oral for both male and females. In animals administered with NSCH, there were neither dead animals nor significant changes of body weights. In addition, no differences were found between control and treated groups in clinical sign, urinalysis, eye examination, hematology, serum chemistry, organ weight and other fingings. No histological lesions were observed in both control and treatment groups. Above data strongly suggset that NSCH in beagle dogs is considered to be safe.

妊娠中督症을 同伴한 妊婦의 胎盤內 免疫globulins, 補體(C₃) 및 纖維素源 沈着에 關한 免疫組織化學的 硏究

黃仁奎,金善行,洪性鳳 고려대학교 의과대학 1985 고려대 의대 잡지 Vol.22 No.1

Nowadays, it is generally accepted that immunological mechanisms are relevant in the materno-fetal relationship. And the abnormal deviation of maternal immune response to paternally derived or organ specific antigens is proposed as the pathogenesis of toxemia. The primary site of antigen-antibody reaction will be the choriodecidual junction because it is the area of direct contact and exchange between mother and feto-placental unit. Therefore this investigation has focused on the term placenta of toxemic women and demonstrated more heavier deposits of IgG, IgM, and fibrinogen in the villi of toxemic placenta than that of normal placenta by the treatment of deparaffinized specimen with anti-immunoglobulins antiserum and avidin-biotinylated peroxidase. The most striking reactions were produced by anti-IgG, anti-IgM, and anti-fibrinogen antiserum in this series. The followings are more detailed results. 1. Anti-IgG antiserum routinely reacted within the syncytiotrophoblast, the peripheral surface of the chorionic villi, as segmental or linear fashion. The staining was not seen in all villi and the pattern was granular or smooth with some areas of villi being more intensively stained than others. The degree and extent of staining were more dense and wide-spread in the placenta of toxemia than that of normal. 2.Anti-IgA antiserum reacted weakly and focally along with the surface of villi as segmental fashion. No difference of staining was noted between toxemic and normal placenta. 3. One of the most striking reaction was produced by anti-IgM antiserum. The pattern and distribution of staining were similar to anti-IgG antiserum treated specimen. There was noticeable difference in the degree and extent of staining between the placenta of toxemia and normal. 4. Generally, anti-complement (C₃) antiserum reacted weakly and focally. This finding stressed the immunological concept of toxemia. 5. One of the prominent reaction was also produced by anti-fibrinogen antiserum. The densely and homogeneously stained areas along the peripheral surface of the chorionic villi were impressive. The widely spreaded staining areas were also noted in the inter-villous spaces and fibrinoid(degeneration) areas which was connected to trophoblastic basement membrane as interrupted fashion. The degree and extent of staining produced by anti-fibrinogen antiserum had the most striking difference between the placenta of toxemia and normal. Above results may allow the conclusion that the more intense immunohistologic or histochemical changes in the placenta of toxemic pregnancy imply that toxemia has definite immunologic background different from that of normal pregnancy.

대장선암에서 p53 과 P-glycoprotein의 분포에 관한 연구

강상균,김의한,장인성,김대중,양승하 순천향의학연구소 1997 Journal of Soonchunhyang Medical Science Vol.3 No.1

Adenocarcinoma of colon and rectum express many oncogenes. The p53 acts as tumor suppressor in normal tissue but mutant forms are known as doing important role in carcinogenesis of many malignant tumors, such as colorectal cancer, gastric cancer, and breast cancer. P-glycoprotein shows distribution in many normal tissues and malignant tumor. This protein occurs multidrug resistance to therapeutic anticancer drug, resulting in poor prognosis of patients. The expression of p53 and P-glycoprotein has been studied by many authors according to clinicopthologic findings of colorectal adenocarcinoma, but these results are controversial yet. To observe the relationship between both antigen and pathologic findings, including prognostic factos, of colorectal adenocarcinoma, we analysed 13 cases adenoma and 62 cases adenocarcinoma then processed for immunohistochemical stain by SLAB method using mouse monoclonal anti-p53 and JSB-1. The results were as followings; 1) The expression rate of p53 in adenoma and adenocarcinoma are 38.5% and 71.0%, respectively, and P-glycoprotein are 46.6% and 58.1%, respectively. 2) The p53 revealed higher expression rate in case of well differnetiated form, invasion to serosa and surrounding adipose tissue, lymphatic metastasis compared to that of moderately and poorly differentiated form, invasion to muscle, no lymphatic metastasis, but no difference accoding to site. 3) P-glycoprotein revealed higher positive rate in case of right side, invasion to surrounding adipose tissue, lymphatic metastasis compared to that of left side, invasion to muscle and serosa, no lymphatic metastasis, but no difference according to differentiation. 4) Both of p53 and P-glycoprotein revealed higher ex pression in case of right side, well and moderately differentiated form, invation to serosa and surrounding adipose tissue, lymphatic metastasis compared to that of left side, poorly differentiated form, invasion to muscle, no lymphatic metastasis. Above results revealed that the expression of p53 begins in adenoma and shows close relation with development of colorectal carcinoma. p53 and P-glycoprotein may reveal the relation with poor prognosis. Adenocarcinoma showing both positive reaction of p53 and P-glycoprotein is also similar prognostic relation.

해상 유류 유출 사고 후, 유류 해양 오염에 따른 주요 해산 어ㆍ패류내 PAHs 추적

황인영,박정규,박관하,김정상,정흥배,배철한 한국환경독성학회 2001 환경독성보건학회지 Vol.16 No.2

Marine organisms such as fish (Sebastes schlegeli) and mussels were cultured in sea water tanks placed at Dukpo area which was contaminated by the two oil spill accidents. Results showed that PAHs concentrations in fish tissue were higher than in fish liver. This was explained by the cytochrome P450 IA induction in fish liver after PAHs exposure. Other studies showed that higher PAHs levels were detected in mussels cultures in oil contaminated area than in control site. From these results, we concluded that Dukpo area is still polluted by oil including PAHs and it takes a long time to recover of oil contamination after the oil spill accidents.