• 제목/요약/키워드: thin membranes

검색결과 187건 처리시간 0.028초

호장근으로부터 분리된 emodin의 혈관신생 억제 활성 (Emodin from Polygonum cuspidatum showed Angiogenesis Inhibiting Activity in vitro)

  • 이태규;김종화;소준노
    • Applied Biological Chemistry
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    • 제46권1호
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    • pp.50-54
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    • 2003
  • 호장근에서 분리한 emodin은 VEGF로 유도된 혈관신생의 한 단계인 혈관내피세포의 이동을 강하게 억제하였다. 또한 emodin은 혈관내피세포 이동을 억제시킨 $0.1\;{\mu}g/ml$ 농도에서 시험관내 혈관신생을 억제하였으며, 그 효과는 농도의존적인 양상을 보였다. 생체내 혈관신생 모델인 CAM assay에서도 emodin은 혈관신생을 억제하였다. 이러한 결과는 emodin이 현재까지 보고된 여러 가지 생리활성 이외에 혈관신생 억제활성을 가지고 있다는 사실을 보여주는 것이다. 따라서 emodin을 함유하고 있는 호장근은 혈관신생 관련 질환에 대한 천연물 유래 치료제의 개발을 위한 중요한 식물자원으로 활용될 수 있을 것이다.

표면수식된 프로리포솜에 의한 표적부위 지향성 약물수송체의 개발 I-갈락토스 당쇄로 표면수식된 리포솜의 간세포 렉틴 결합성- (Development of Target-Specific Drug Delivery Systems Using Glycosylated Proliposome I-Binding of Asialofetuin-Labeled Liposomes to Lectin RCA-)

  • 심창구;이창용;김종국
    • Journal of Pharmaceutical Investigation
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    • 제22권2호
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    • pp.155-161
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    • 1992
  • Although glycosylated liposomes have attracted much attention as targeting delivery systems (DDS) of drugs to specific organs which have glycoside receptors, physical instability of liposomes greatly limits their practical application. In this case, proliposomes might be a potential answer to solve this problem. Utilizing the proliposomes as tageting DDS has been a goal of our series of works; we have tried to develop DDS which form liposomes uppon adding water and can deliver drugs to specific target organs/cells such as hepatocytes. In this paper, preparation of glycosylated liposomes and binding of the liposomes with lectin (agglutinin RCA 120) was studied. Asialoletuin (AF) was selected as a model compound which has galactose terminal and is favorable for binding with galactose receptor on the surface of hepatocytes. AF was obtained by splitting the terminal N-acetylneuraminic acid (NANA) of fetuin. Small unilamellar AF-liposomes were prepared by mixing aqueous solution of AF-palmitate with thin film of phosphatidyl choline and cholesterol (30:10 w/w) formed on the innersurface of the round bottomed flask. They were successively extruded through polycarbonate membranes (0.45 mm). Palmitoyl-AF not incorporated into the liposomal bilayer was separated from liposomes by a Sepharose 4B column equilibrated with 10 mM Tris-HCI buffered saline. Lectin (agglutinin RCA 120) was added to the suspension of AF-liposomes and incubated at $37^{\circ}C$ for 2 hr. After centrifugation, the unbound lectin in the supernatant was assayed for protein. The binding of the lectin to AF-liposomes (AF content 2.8 nmole) at $37^{\circ}C$ was linear at least upto 35 mg of lectin indicating high affinity association of the lectin to AF molecules of the liposomes.

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내안각 췌피교정술 후 발생한 유루 (A Case Report of Epiphora after Epicanthoplasty)

  • 송선호;윤을식;동은상
    • 대한두개안면성형외과학회지
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    • 제11권1호
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    • pp.41-44
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    • 2010
  • Purpose: The epicanthus is a specific feature in Asian. Many techniques have been described to eliminate the epicanthal fold: resection of glabellar skin, resection of medial canthal skin, V-Y advancement, V-W technique, modified Z-plasty, multiple Z-plasties, and others. The authors observed postoperative epiphora after correction of epicanthal fold by periciliary skin flap without damaging lacrimal duct. Methods: A 19-year-old woman underwent non-incisional blepharoplasty, septorhinoplasty, and periciliary epicanthoplasty. On her history, she didn't have any symptom of epiphora preoperatively. And there was no specific complaint of epiphora during the postoperative two weeks. However epiphora got worse from one month after the surgery. She was out of this country, so the patient re-visited the clinic on the postoperative six months for this on-going symptom. On an ophthalmologic examination, patient's lacrimal duct and sac was intact but both lacrimal puncta of the patient were covered with a thin membrane. This membrane was punctuated by a 25 gauge needle and dilated with a standard dilator. Results: After ophthalmologic treatment, no recurrence was observed during five weeks of follow-up periods. Conclusion: Both lacrimal puncta of the patient were only covered with membranes. And we could not confirm the direct relationship between periciliary epicanthoplasty and postoperative epiphora. The probable factors will be a predisposing narrowed punctum, post operative peri-punctal edema and decrease in muscular function of orbicularis oculi.

양이온성 지질이 포함된 PEG 리포솜의 세포내 이입 및 항암효력 평가 (Intracellular delivery and anti-tumor activity of polyethyleneglycol liposomes containing cationic lipid)

  • 정순화;김성규;정석현;성하수;조선행;신병철
    • Journal of Pharmaceutical Investigation
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    • 제38권3호
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    • pp.163-169
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    • 2008
  • Liposomes are spherical vesicles composed of lipid bilayer membranes. However, the conventional liposomes have been found to be plagued by rapid opsonization and taken up by the reticuloendothelial system (RES), resulting in shortened circulation time and limited intracellular uptake to target cell. In this study, polyethyleneglycol-cationic liposomes (PCL) containing cationic lipid and DSPE-mPEG were prepared by thin film cast-hydration method. The PEG liposomes had approximately $97.0{\pm}1.3\;nm$ of mean particle diameter and $-21.7{\pm}1.2\;mV$ of zeta potential value. PCL had $96.4{\pm}1.8\;nm$ of mean particle diameter and $-8.7{\pm}1.1\;mV$ of zeta potential value with a decrease of about 10 mV compared to the PEG liposomes. Loading of model drug, doxorubicin (DOX), in liposomes were carried out by using remote loading method and the loading efficiency of DOX in liposomes was about $95.0{\pm}1.9%$. Intracellular uptake and cytotoxicity of PCL were higher than that of PEG liposomes to murine B16F10 melanoma cells. In addition, anti-tumor activity of PCL was similar to that of PEG liposomes on growth of A549 human lung carcinoma in BALB/c mice. Consequently, PCL modified with cationic lipid may be applicable as anticancer drug carriers that can increase intracellular uptake and therapeutic efficacy.

동양달팽이 Nesiohelix samarangae 소화관에서의 cellulase 활성에 대한 세포화학적 및 면역세포화학적 연구 (Cytochemical and Immunocytochemical Study on the Cellulase Activity in the Digestive Tract of the Land Snail Nesiohelix)

  • 정계헌;이용석;김은정
    • 한국패류학회지
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    • 제14권2호
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    • pp.149-159
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    • 1998
  • In order to observe the anticellulolytic localization in the epithelia of the digestive tract such as esophagus, crop, and intestine of a Korean land snail N. samarangae, a cytochemical method and a immunogold labelling method were applied. For the cytochemical study on the cellulase activity, Benedict reaction method applied. And for the immunocytochemical study, the rabbit serum immunoglobuins (IgG) was obtained from the rabbits injected with cellulase which was extracted from body fluid of the snail. The digestive tract tissues of N. samarangae were fixed with 4% paraformaldehyde and 2% OsO4 and embedded in Lowicryl K4M at -40$^{\circ}C$ under UV light (360 nm). The thin sections were loaded on the nickel grids and stained with the serum IgG and protein A-gold complex (particle size: 10 nm). Observations were undertaken with transmission electron microscope (Jeol, JEM-1010). The epithelium of the digestive tract was consisted of five types of cells. In the cytochemical study, the reaction products were found along the periphery of the vacuoles derived from the Bebedict reaction. In the immunocytochemical study, the protein-A gold particles were selectively labelled in Type 1, Type 3 and Type 4 cells in intestinal tissue. membranes of rER, in the surrounding cytoplasm of the rER and secretory granules, and in the apical cytoplasm of the cells. On the material being secreted from the apical cytoplasm was also labelled with the immunogold particles. The all results obtained throughtout present study suggest that the intestinal epithelium of the snail N. samarangae seretes cellulase as one of digestive enzymes.

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거대고리 중성 운반체를 갖는 Hg(II)이온 선택성 전극 (Hg(II) ion- Selective Electrodes with Neutral Carriers of Macrocycles)

  • 정오진
    • 한국환경과학회지
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    • 제5권2호
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    • pp.211-220
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    • 1996
  • 두 개의 황과 셀렌의 주개원자를 포함한 새로운 thia 및 diselena 크라운에데르 화합물을 합성하였다. 그리고 이 화합들을 중성운반체로 하고 PVC-가소제 (STPB)를 포함한 Hg(ll) 선택성 전극을 제작하였다. 이 전극들을 이용하여 여러 이온들의 전기화학적 선택성, 중성운반체의 종류 및 농도와 선택막의 매질에 대한 효과 그리고 실험용액의 pH변화에 대한 전극의 선택적 감응성들의 영향을 각각 검토하였다. 1,10-diselena-18-crown-6-PVC-STPB의 중성운반체의 막전극은 $10^{-2}$-10- M $Hg^{2+}$ 이온의 농도범위에서 ${28.2}\pm{0.6}$의 Nernstian 기울기를 갖는 좋은 선형적 감응성을 갖는다. 그리고 이 전극은 pH 2.5~6.0 범 위에서 알칼리토 금속, 몇가지 중금속 및 희토류 금속 이온에 대하여 좋은 선택성을 갖는다. 특히 이 전극은 수용액 중에서.$1^-$ 이온으로 Hg^{2-}$ 이온을 전위차 적정할 수 있는 센서로서 응용할 수 있다.

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Benzo(a)pyrene-Triglyceride Adduct: a Potential Molecular Biomarker for Carcinogen Exposure

  • Lee, Byung-Mu
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2002년도 국제심포지움
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    • pp.20-45
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    • 2002
  • In this study, we demonstrated the in vitro and in vivo formation of carcinogen-lipid adduct and its correlation with DNA or protein adducts. The lipids from serum or hepatocyte membranes of Spragu-Dawley rats. human serum, and standard major lipids were in vitro reacted with benzo[a]pyrene(BP) and BP metabolites. 7,8-Dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]-pyrene(BPDE-I), an ultimate carcinogenic form of BP, was covalently bound to triglyceride(TG). BPDE-I-TG adducts isolated by thin-layer chromatography (TLC) were further detected by high performance liquid chromatography(HPLC). TGs, including triolein, tripalmitin and tristearin, showed positive reactions with BPDE-I. However, cholesterol, phospholipids(Phosphatidylcholine, phosphatidyl-ethanolamine, phosphatidyl-inositol and sphingomyelin) and nonesterified fatty acids(palmitic acid, oleic acid, linoleic acid and stearic acid) did not react with BPDE-I. In addition, other BP metabolites (BP-phenols and -diols) did not react with TG, which TG appeared to be the most reactive lipid yet studied with respect to its ability to form an adduct with BPDE-I. There was a clear-cut dose-respect to its ability to form an adduct with BPDE-I-lipid adduct in vitro between TG and [1,3-3H]BPDE-I. In an animal study, BPDE-I-TG was also formed in the serum of rats orally treated with BP(25 mg/rat). Also, obvious correlations between [3H]BP related-biomolecule adducts (DNA, protein) or lipid damage and the BPDE-I-TG adduct were obtained in various tissues of mice i.p. treated with [3H]BP. These data suggest that TG can form an adduct with BPDE-I, as do other macromolecules (DNA, RNA, and protein). Therefore, a carcinogen-lipid adduct would be a useful biomarker for chemical carcinogenesis research and cancer risk assessment.

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흉수의 혈관육종의 세포학적 소견 - 1예 보고 - (Cytologic Features of an Angiosarcoma in Pleural Fluid - A Case Report -)

  • 주영채;박인서;김윤주;한혜승;한지영
    • 대한세포병리학회지
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    • 제10권1호
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    • pp.61-66
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    • 1999
  • Angiosarcomas are rare tumors, seen most commonly in the skin and soft tissue of head and neck legion. But it has been described in numerous body sites including thyroid, breast, liver, spleen, bone, etc.. Their biological behaviors depend on the microscopic grade, site of origin, and multifocality. We report the unique cytological features of an angiosarcoma in pleural fluid. A 61-year-old woman presented with a 6 month history of dyspnea on exertion and chest pain. Chest computerized tomography(CT) revealed multiple subpleural small nodules in the right lung and widespread all space consolidation and pleural effusion in the left lung. CT of liver revealed multiple small low attenuated lesion. The smears obtained from pleural fluid showed hypocellularity with a hemorrhagic background. The tumor cells were highly pleomorphic oval or spindle in shape and presented singly, in loose groups, in knitted syncytial aggregates, and in acinar pattern. Their nuclei had vesicular chromatin with delineated, thick nuclear membranes and occasionally a large eosinophilic, prominent nucleolus. The cytoplasm was plump, thin or protected in spindly fashion. Almost ail tumor cells showed variable sized intracytoplasmic vacuoles and their nuclei were sometimes crescentic by a huge vacuole. Occasional binucleated tumor cells and mitotic figures were present. Cellular debris and streaky materials were identified. Needle biopsy specimen from the pleura revealed anastomosing slit-like spaces lined by pleomorphic tumor cells. The tumor cells showed a strong reactivity for CD31 and vimentin and focal weak reactivity for factor VIII-related antigen.

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Ti 합금을 이용한 항공기용 Flexible PTO 샤프트 개발 시험 (Development Test for Flexible PTO Shaft Made of Ti Alloy for Aircraft)

  • 이주홍;강보식;유현석;이지만;조해용
    • 대한기계학회논문집A
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    • 제40권8호
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    • pp.759-765
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    • 2016
  • 항공기 등에 사용되는 Flexible PTO(Power Take-Off) 샤프트는 스프링 특성을 좋게 하기 위해 여러장의 얇은 멤브레인을 용접한 형태로 1950년대에 이미 개발됐으며, AMAD(Aircraft Mounted Accessory Drive) 기어박스와 EMAD(Engine Mounted Accessary Drive) 기어박스 사이에서 회전동력을 전달한다. 이런 종류의 샤프트는 가볍고 특히 스프링 특성이 좋기 때문에 축 정렬이 틀어진 고속회전 상태에서도 안정적으로 회전동력을 전달할 수 있어 대부분의 전투기에 사용된다. 이번 연구에서 티타늄 합금으로 개발된 Flexible PTO 샤프트의 구조해석을 통해 제품의 안전성을 확인하였고, 실제 실험실에서 진행된 고속회전 시험에서 굽힘과 비틀림 부하를 동시에 인가하여 샤프트의 고주기 피로에 대한 내성을 실증하였다. 또한, 고주기 피로 시험 조건에서 항공기용 볼 조인트의 마모 특성 분석을 통해 수명을 예측하였다.

상악동점막 천공의 미세봉합술을 이용한 처치 (REPAIR OF THE PERFORATED SINUS MEMBRANE WITH A MICRO-SUTURE TECHNIQUE : REPORT OF CASES)

  • 임대호;장소정;김경아;백진아;고승오;신효근
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제29권3호
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    • pp.241-249
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    • 2007
  • An augmentation of the maxillary sinus floor facilitates placement of dental implants in the posterior atrophic maxilla. However, a maxillary sinus augmentation has potential complications that can lead to early failure and loss of the bone graft. One specific complication is sinus membrane perforation. Especially, large perforations may cause loss of the graft materials into the sinus and infection, so, early failure of the sinus lift. Attempts at managing sinus membrane perforations are difficult because of the limited access to them and friability of the thin Schneiderian membrane. Repair of sinus membrane perforations intraoperatively may be performed using a variety of techniques and materials, including sutures, collagen membranes, fibrin glue. Inspite of various repair technique, as has been reported extensively in the literature, large perforations represent an absolute contraindication to the continuation of surgery. But, we obtained clinically favorable results in cases that show repair of the perforated sinus membrane with a micro-suture technique by 4X Loupe ($Surgitel^{(R)}$ Loupe, General Scientific Corporation) in large perforation. The objective of this presentation is to report of several cases of repair of the perforated sinus membrane with micro-suture technique using 7.0 or 8.0 suture materials, to make a brief review of the literature about various technique managing perforated sinus membrane.